阅读说明：本技术 供气系统及离子源的供气方法 (Gas supply system and gas supply method of ion source ) 是由 於鹏飞 李飞逸 汪东 于 2021-09-01 设计创作，主要内容包括：本发明提供了一种供气系统及离子源的供气方法,包括反应腔、第一加热装置、流量控制器和气体管路；所述反应腔用于放置固体源；所述气体管路的一端连接所述反应腔,另一端用于连接所述离子源；所述第一加热装置设置于所述反应腔上,并用于加热所述固体源至预设温度,以使所述固体源气化,所述固体源气化后的气体由所述反应腔流出并通过所述气体管路进入所述离子源。该供气系统可使固体源加热气化并为离子源提供稳定的气流,从而保证晶圆表面离子注入的均匀性,提高晶圆离子注入的产能,同时延长离子源的保养周期。(The invention provides a gas supply system and a gas supply method of an ion source, which comprise a reaction cavity, a first heating device, a flow controller and a gas pipeline; the reaction chamber is used for placing a solid source; one end of the gas pipeline is connected with the reaction cavity, and the other end of the gas pipeline is used for connecting the ion source; the first heating device is arranged on the reaction cavity and used for heating the solid source to a preset temperature so as to gasify the solid source, and gas obtained after gasification of the solid source flows out of the reaction cavity and enters the ion source through the gas pipeline. The gas supply system can heat and gasify the solid source and provide stable gas flow for the ion source, thereby ensuring the uniformity of ion implantation on the surface of the wafer, improving the productivity of the ion implantation of the wafer and simultaneously prolonging the maintenance period of the ion source.)

1. A gas supply system for providing a stable solid source gasification gas flow to an ion source is characterized by comprising a reaction chamber, a first heating device, a flow controller and a gas pipeline;

the reaction chamber is used for placing a solid source; one end of the gas pipeline is connected with the reaction cavity, and the other end of the gas pipeline is used for connecting the ion source;

the first heating device is arranged on the reaction cavity and used for heating the reaction cavity to a preset temperature so as to gasify the solid source in the reaction cavity, and gas generated after the solid source is gasified enters the ion source through the gas pipeline;

the flow controller is used for controlling the flow of the gas entering the ion source within a preset range.

2. The gas supply system of claim 1, further comprising a control device and a detection device, the control device being in communication with the first heating device, the flow controller, and the detection device, respectively;

the detection device is used for measuring the pressure and/or temperature in the reaction cavity;

the control device is used for controlling the heating temperature of the first heating device according to the pressure and/or the temperature in the reaction cavity;

the control device is further used for controlling the flow controller to enable the flow of the gas entering the ion source to be within the preset range.

3. The gas supply system according to claim 2, wherein the detecting means includes a first temperature detecting means and a pressure detecting means, both of which are connected to the reaction chamber, the first temperature detecting means being configured to measure a temperature in the reaction chamber, the pressure detecting means being configured to measure a pressure in the reaction chamber;

the control device is used for controlling the heating temperature of the first heating device according to the pressure in the reaction cavity measured by the pressure detection device.

4. The air supply system of claim 2, further comprising a second heating device and a second temperature detection device, both the second heating device and the second temperature detection device being in communication with the control device;

the second heating device and the second temperature detection device are both arranged on the gas pipeline; the second heating device is used for heating the gas pipeline; the second temperature detection device is used for measuring the temperature in the gas pipeline;

the control device is also used for controlling the heating temperature of the second heating device according to the temperature in the gas pipeline measured by the second temperature detection device;

the heating temperature of the second heating device is greater than or equal to the heating temperature of the first heating device.

5. The gas supply system of claim 4, wherein the flow controller is disposed on the gas line between the reaction chamber and the second heating device;

the number of the second temperature detection devices is at least two, one of the second temperature detection devices is arranged between the reaction cavity and the flow controller, and the other one of the second temperature detection devices is arranged between the second heating device and the ion source.

6. The gas supply system of claim 4, wherein the second heating device is a heating tape, the first heating device is a heating rod disposed inside the reaction chamber, and the flow controller is a mass flow controller.

7. An air supply system as claimed in any one of claims 1to 6, further comprising an air supply connected to the reaction chamber for delivering a shielding gas to the reaction chamber.

8. The gas supply system of claim 7, wherein a first valve is disposed between the gas supply and the reaction chamber, and a second valve is disposed on the gas line and is connected in parallel to the flow controller.

9. The gas supply system of claim 8, further comprising a gas extraction device coupled to the reaction chamber; the air extractor is used for extracting air from the reaction cavity.

10. The gas supply system according to claim 9, wherein the gas-extracting device is a vacuum pump of the ion source, and the vacuum pump is connected with the gas pipeline;

when the vacuum pump is used for pumping the reaction cavity, the second valve piece is opened, the flow controller is closed, and the vacuum pump is used for pumping the reaction cavity through a gas pipeline provided with the second valve piece.

11. The gas supply system according to any of claims 1-6, wherein the flow controller is disposed on the gas line, wherein a third valve is disposed on the gas line between the flow controller and the reaction chamber, and/or wherein a fourth valve is disposed on the gas line between the flow controller and the ion source.

12. A gas supply system according to any of claims 1to 6, wherein the ion source is indium trichloride and the first heating means is heated to a temperature of 335 ℃ to 385 ℃.

13. A gas supply method for an ion source, which is performed by supplying gas to the ion source using the gas supply system according to claim 1, wherein the gas supply method comprises the steps of:

the method comprises the following steps: placing a solid source into a reaction chamber;

step two: pumping the reaction cavity to enable the reaction cavity to be in a negative pressure state;

step three: after the reaction chamber is in a negative pressure state, heating the reaction chamber to a preset temperature by using a first heating device to gasify the solid source;

step four: and gas generated after the solid source is gasified enters the ion source through the gas pipeline, and in the process, the flow rate of the gas entering the ion source is controlled by a flow controller and is kept within a preset range.

14. The gas supply method of claim 13, wherein the gas supply system further comprises a control device and a pressure detection device which are in communication connection, and the gas supply method further comprises:

when the gas flow in the gas pipeline reaches a preset range, determining the current pressure in the reaction cavity measured by the pressure detection device as a target pressure value;

and in the process of gasifying the solid source, when the actual pressure value measured by the pressure detection device deviates from the target pressure value, adjusting the heating temperature of the first heating device by using the control device so as to maintain the actual flow rate of the gas within the preset range and maintain the temperature in the reaction cavity at the preset temperature.

15. The method of claim 14, further comprising:

and after the temperature in the reaction cavity reaches the set maximum temperature, if the actual pressure value measured by the pressure detection device is lower than the target pressure value and the gas in the gas pipeline has no flow, determining that the gasification of the solid source is finished.

16. The gas supply method of the ion source according to claim 14 or 15, wherein the gas supply system further comprises a second heating device and a second temperature detection device, the gas supply method further comprising:

heating the gas pipeline by using the second heating device, and detecting the actual temperature in the gas pipeline in real time by using the second temperature detection device;

adjusting the heating temperature of the second heating device by using the control device according to the actual temperature in the gas pipeline;

wherein the heating temperature of the second heating device is greater than or equal to the heating temperature of the first heating device.

17. A method according to claim 14 or 15, wherein the step of adjusting the heating temperature of the first heating means by the control means comprises:

when the actual pressure value measured by the pressure detection device is higher than the target pressure value, the control device reduces the heating temperature of the first heating device; alternatively, the first and second electrodes may be,

when the actual pressure value measured by the pressure detection means is lower than the target pressure value, the control means increases the temperature of the first heating means.

18. A method of supplying a gas to an ion source as claimed in claim 13, further comprising step five, said step five comprising the steps of:

1) after the solid source is gasified, filling protective gas into the reaction cavity, and detecting the pressure in the reaction cavity;

2) stopping filling the protective gas when the pressure in the reaction cavity reaches the target pressure;

3) after the protective gas is stopped being filled, the reaction cavity is pumped, so that the pressure in the reaction cavity is in a negative pressure state;

4) repeating the steps 1) to 3) for a plurality of times to remove residual substances in the reaction cavity;

5) and after removing the residual substances in the reaction cavity, filling protective gas into the reaction cavity after the temperature in the reaction cavity is reduced to normal temperature, and filling a new solid source into the reaction cavity after the pressure in the reaction cavity reaches a certain pressure.

19. The method of claim 13, wherein the first heating device is heated to a temperature of 335 ℃ to 385 ℃ and/or when the reaction is performedWhen the reaction cavity is in the negative pressure state, the vacuum degree in the reaction cavity is not lower than 1E^-5Torr。

Technical Field

The invention relates to the technical field of semiconductor manufacturing, in particular to a gas supply system and a gas supply method of an ion source.

Background

Ion implanters are critical devices in the fabrication of integrated circuits, and ion implantation is a technique for doping regions near the surface of a semiconductor wafer in order to change the carrier concentration and conductivity type of the semiconductor. In ion implantation, a gas source to be implanted needs to be introduced into an electric field of an ion source and ionized into ions in the electric field of the ion source. If the material to be injected is a solid source, it is also heated to vaporize it into a vapor phase and then introduced into the source.

The existing ion implanter generally adopts a mode of loading a solid source into an ion source and introducing gas by heating the inside of the ion source to gasify the solid source. The gas introduced by adopting the method has the advantages that the heating temperature and the heating pressure of the solid source placed in the ion source cannot be accurately controlled, and meanwhile, the residual solid amount of the solid source is gradually reduced along with the gasification, so that the gas flow generated by the gasification of the solid source is unstable, the ion beam is unstable during ion implantation, and the uniformity of the implanted ions on the surface of the wafer is influenced. Moreover, because the loading capacity of the ion source is limited, only a small number of solid sources can be accommodated, and the ion source needs to be maintained after a small number of solid sources are gasified, the maintenance period of the ion source is greatly shortened, the operating frequency of operators is increased, and the service life of the ion source is shortened.

Disclosure of Invention

The invention aims to provide a gas supply system and a gas supply method of an ion source, which are used for providing stable solid source gasification gas flow for the ion source and shortening the maintenance period of the ion source.

In order to solve the above technical problems, an object of the present invention is to provide a gas supply system for supplying a stable solid source gasification gas flow to an ion source, comprising a reaction chamber, a first heating device, a flow controller and a gas pipeline;

the reaction chamber is used for placing a solid source; one end of the gas pipeline is connected with the reaction cavity, and the other end of the gas pipeline is used for connecting the ion source;

the first heating device is arranged on the reaction cavity and used for heating the reaction cavity to a preset temperature so as to gasify the solid source in the reaction cavity, and gas generated after the solid source is gasified enters the ion source through the gas pipeline;

the flow controller is used for controlling the flow of the gas entering the ion source within a preset range.

Optionally, the gas supply system further includes a control device and a detection device, and the control device is in communication connection with the first heating device, the flow controller and the detection device respectively;

the detection device is used for measuring the pressure and/or temperature in the reaction cavity;

the control device is used for controlling the heating temperature of the first heating device according to the pressure and/or the temperature in the reaction cavity;

the control device is further used for controlling the flow controller to enable the flow of the gas entering the ion source to be within the preset range.

Optionally, the detection device includes a first temperature detection device and a pressure detection device, both the first temperature detection device and the pressure detection device are connected to the reaction chamber, the first temperature detection device is configured to measure a temperature in the reaction chamber, and the pressure detection device is configured to measure a pressure in the reaction chamber;

the control device is used for controlling the heating temperature of the first heating device according to the pressure in the reaction cavity measured by the pressure detection device.

Optionally, the pressure detection device is a vacuum gauge, and the first temperature detection device is a thermometer.

Optionally, the gas supply system further comprises a second heating device and a second temperature detection device, and both the second heating device and the second temperature detection device are in communication connection with the control device;

the second heating device and the second temperature detection device are both arranged on the gas pipeline; the second heating device is used for heating the gas pipeline; the second temperature detection device is used for measuring the temperature in the gas pipeline;

the control device is also used for controlling the heating temperature of the second heating device according to the temperature in the gas pipeline measured by the second temperature detection device;

the heating temperature of the second heating device is greater than or equal to the heating temperature of the first heating device.

Optionally, the flow controller is disposed on the gas pipeline and between the reaction chamber and the second heating device;

the number of the second temperature detection devices is at least two, one of the second temperature detection devices is arranged between the reaction cavity and the flow controller, and the other one of the second temperature detection devices is arranged between the second heating device and the ion source.

Optionally, the second heating device is a heating belt, the first heating device is a heating rod arranged inside the reaction chamber, and the flow controller is a mass flow controller.

Optionally, the gas supply system further comprises a gas supply device, the gas supply device is connected with the reaction cavity, and the gas supply device is used for conveying protective gas to the reaction cavity.

Optionally, a first valve is arranged between the gas supply device and the reaction chamber, a second valve is arranged on the gas pipeline, and the second valve and the flow controller are arranged in parallel.

Optionally, the gas supply system further comprises a gas extraction device connected with the reaction chamber; the air extractor is used for extracting air from the reaction cavity.

Optionally, the air extracting device is a vacuum pump provided with the ion source, and the vacuum pump is connected with the gas pipeline.

When the vacuum pump is used for pumping the reaction cavity, the second valve piece is opened, the flow controller is closed, and the vacuum pump is used for pumping the reaction cavity through a gas pipeline provided with the second valve piece.

Optionally, the flow controller is disposed on the gas pipeline, a third valve is disposed on the gas pipeline, the third valve is disposed between the flow controller and the reaction chamber, and/or a fourth valve is disposed on the gas pipeline, and the fourth valve is disposed between the flow controller and the ion source.

Optionally, the ion source is indium trichloride, and the heating temperature of the first heating device is 335-385 ℃.

In order to solve the above technical problem, another object of the present invention is to provide a gas supply method for an ion source, in which the gas supply system is adopted to supply gas to the ion source, the gas supply method includes the following steps:

the method comprises the following steps: placing a solid source into a reaction chamber;

step two: pumping the reaction cavity to enable the reaction cavity to be in a negative pressure state;

step three: after the reaction chamber is in a negative pressure state, heating the reaction chamber to a preset temperature by using a first heating device to gasify the solid source;

step four: and gas generated after the solid source is gasified enters the ion source through the gas pipeline, and in the process, the flow rate of the gas entering the ion source is controlled by a flow controller and is kept within a preset range.

Optionally, the gas supply system further includes a control device and a pressure detection device, which are connected in communication, and the gas supply method further includes:

when the gas flow in the gas pipeline reaches a preset range, determining the current pressure in the reaction cavity measured by the pressure detection device as a target pressure value;

and in the process of gasifying the solid source, when the actual pressure value measured by the pressure detection device deviates from the target pressure value, adjusting the heating temperature of the first heating device by using the control device so as to maintain the actual flow rate of the gas within the preset range and maintain the temperature in the reaction cavity at the preset temperature.

Optionally, the gas supply method further includes:

and after the temperature in the reaction cavity reaches the set maximum temperature, if the actual pressure value measured by the pressure detection device is lower than the target pressure value and the gas in the gas pipeline has no flow, determining that the gasification of the solid source is finished.

Optionally, the gas supply system further includes a second heating device and a second temperature detection device, and the gas supply method further includes:

heating the temperature of the gas pipeline by using the second heating device, and detecting the actual temperature in the gas pipeline in real time by using the second temperature detection device;

adjusting the heating temperature of the second heating device by using the control device according to the actual temperature in the gas pipeline;

wherein the heating temperature of the second heating device is greater than or equal to the heating temperature of the first heating device.

Optionally, the specific process of adjusting the heating temperature of the first heating device by using the control device is as follows:

when the actual pressure value measured by the pressure detection device is higher than the target pressure value, the control device reduces the heating temperature of the first heating device; alternatively, the first and second electrodes may be,

when the actual pressure value measured by the pressure detection means is lower than the target pressure value, the control means increases the temperature of the first heating means.

Optionally, the gas supply method further includes a fifth step, where the fifth step includes the following steps: :

1) after the solid source is gasified, filling protective gas into the reaction cavity, and detecting the pressure in the reaction cavity;

2) stopping filling the protective gas when the pressure in the reaction cavity reaches the target pressure;

3) after the protective gas is stopped being filled, the reaction cavity is pumped, so that the pressure in the reaction cavity is in a negative pressure state;

4) repeating the steps 1) to 3) for a plurality of times to remove residual substances in the reaction cavity;

5) and after removing the residual substances in the reaction cavity, filling protective gas into the reaction cavity after the temperature in the reaction cavity is reduced to normal temperature, and filling a new solid source into the reaction cavity after the pressure in the reaction cavity reaches a certain pressure.

Optionally, the heating temperature of the first heating device is 335-385 ℃, and/or when the reaction chamber is in the negative pressure state, the vacuum degree in the reaction chamber is not lower than 1E^-5Torr。

In the gas supply system and the gas supply method of the ion source, the gas supply system is arranged at the front end of the ion source, so that stable solid source gasification gas flow can be provided for the ion source, and stable ion beams can be obtained by ionizing the gas flow in the ion source due to the stable gas flow obtained during the gasification of the solid source, so that the uniformity of ion implantation on the surface of a wafer is ensured, and the processing quality is ensured. Compared with the solid source directly placed in the ion source, the gas supply system and the gas supply method of the invention are used for continuously and stably supplying gas, the ion implantation efficiency is greatly improved, and the wafer ion implantation capacity is improved.

In the prior art, when the solid source is directly placed in the ion source, the ion source needs to be maintained every time the solid source is gasified, and because the ion source can only accommodate a small amount of solid source, the ion source needs to be maintained in advance before the proper maintenance period of the ion source is reached. The gas supply system and the ion source can be isolated when the solid source is filled (namely the gas supply system is arranged outside the ion source and is arranged independently), the ion source does not need to be maintained due to the consumption of the solid source inside the ion source, the maintenance period of the ion source is prolonged, and the service life of the ion source is prolonged. The data show that when the gas supply system and the gas supply method are used for injecting indium ions, the stability of ion beam current in the ion source is improved by about 25%, the productivity of wafers is improved by about 30%, and the maintenance period of the ion source is prolonged from 14 days to 20 days.

According to the gas supply system and the gas supply method, the heating temperature of the heating device of the reaction cavity is preferably adjusted by the control device according to the pressure value in the reaction cavity, so that the gas flow generated in the solid source gasification process can be accurately and effectively controlled, the stability of the gas flow entering the ion source is ensured, the excessive consumption of the solid source caused by untimely adjustment of the reaction cavity is avoided, and the utilization efficiency of the solid source is increased.

Drawings

Fig. 1 is a schematic structural view of an air supply system provided in accordance with a preferred embodiment of the present invention;

fig. 2 is a schematic diagram of a closed-loop control of a control device in an air supply system according to a preferred embodiment of the present invention;

FIG. 3 is a graph illustrating ion implantation uniformity across a wafer surface at various dates measured while a solid source is placed in an ion source according to the prior art;

fig. 4 is a graph illustrating uniformity of ion implantation on the surface of a wafer measured at different dates using a gas supply system according to a preferred embodiment of the present invention.

Wherein the reference numerals are as follows:

11-an ion source; 12-a reaction chamber;

13-a flow controller; 14-gas line;

15-a pressure detection device; 16-a control device;

171-a first heating device; 172-a second heating device;

181-first temperature detection means; 182-second temperature detection means;

19-gas supply means;

201-a first valve element; 202-a second valve element;

203-a third valve element; 204-fourth valve element.

Detailed Description

The invention is described in further detail below with reference to the figures and specific examples. The advantages and features of the present invention will become more apparent from the following description. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention.

As used in this specification, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. As used in this specification, the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise. As used in this specification, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

Fig. 1 is a schematic structural view of an air supply system according to a preferred embodiment of the present invention, and fig. 2 is a schematic closed-loop control diagram of a control device in the air supply system according to the preferred embodiment of the present invention.

Referring to fig. 1 and 2, an embodiment of the present invention provides a gas supply system for supplying gas to an ion source 11 to provide a stable solid source vaporizing gas flow to the ion source 11. The gas supply system includes a reaction chamber 12, a flow controller 13, a gas line 14, and a first heating device 171. The gas supply system preferably further comprises a control device 16, the control device 16 being in communication with the flow controller 13 and the first heating device 171. The gas supply system preferably further comprises a detection device in communication with the control device 16. In a preferred embodiment of the present invention, the sensing means may include a pressure sensing means 15 or a first temperature sensing means 181. In another embodiment of the present invention, the detecting device may also include both the pressure detecting device 15 and the first temperature detecting device 181. The air supply system may further include a second heating device 172 and a second temperature sensing device 182.

Wherein, the reaction chamber 12 is used for placing a solid source, one end of the gas pipeline 14 is connected with the reaction chamber 12, and the other end is used for connecting with the ion source 11. The first heating device 171 is disposed on the reaction chamber 12 and is used for heating the reaction chamber 12 to gasify the solid source, and the gas generated by gasifying the solid source flows out of the reaction chamber 12 and enters the ion source 11 through the gas pipeline 14. The flow controller 13 is used to control the flow rate of the gas generated by the gasification of the solid source into the ion source 11 within a predetermined range. The type of the solid source is not limited in the present application, and different types of solid sources, such as indium trichloride, indium hexafluoride or other solid sources, can be placed inside the reaction chamber 12 as required.

The gas supply system of the present invention ensures the stability of the gas delivered into the ion source 11 by adding the reaction chamber 12 with the first heating device 171 at the front end of the ion source 11 and by using the flow controller 13 to control the flow of the gas in a steady flow manner during the gas delivery process, thereby ensuring the stable performance of the subsequent steps of ion implantation. Moreover, the gas supply system is used for continuously and stably supplying gas, so that the ion implantation efficiency is greatly improved, and the wafer ion implantation capacity is improved. Meanwhile, an independent gas supply system is arranged outside the ion source, so that the ion source is not required to be maintained after the solid source filled in the ion source is gasified, the maintenance period of the ion source is prolonged, and the service life of the ion source is prolonged.

In the present invention, when an ion implanter is used to implant ions into a wafer, the stability of the gas flow entering the ion source 11 can be reflected by measuring the uniformity of the implanted ions on the surface of the wafer, and the more stable the gas flow entering the ion source during the wafer ion implantation process is, the closer the implantation effect of each region after the wafer ion implantation is, the smaller the ion implantation uniformity value is, the better the ion implantation uniformity on the surface of the wafer is.

Fig. 3 is a graph of ion implantation uniformity across the surface of a wafer measured at different dates when a solid source was placed in an ion source according to the prior art, wherein the abscissa is date (day), 1, 2, … …, and 30 respectively represent day one, day two, day … …, and day 30, and the ordinate is the uniformity of ion implantation (sigma) across the surface of the wafer.

As shown in fig. 3, when the solid source is placed in the ion source 11 as a gas source, the uniformity of the wafer surface obtained by ion implantation is large and generally distributed between 11 sigma and 23sigma, which indicates that the gas flow fluctuation in the ion source is large and the gas flow stability is poor during the ion implantation process of the wafer when the solid source is placed in the ion source. Meanwhile, as shown in fig. 3, the uniformity values of the wafer surfaces on different dates are very different, that is, the gas flow rate generated by the gasification of the solid source is very different when the wafers on different dates are subjected to ion implantation, so that when the gas is provided to the ion source by placing the solid source in the ion source, the solid source cannot provide stable gas flow during the ion implantation of the wafers, the gas flow rate entering the ion source cannot be kept uniform during the ion implantation of the wafers each time, and the uniformity and quality stability of the wafer surfaces after the ion implantation are poor.

Fig. 4 is a graph of uniformity of ion implantation on the surface of a wafer measured at different dates when the gas supply system of the present invention is used, and it can be seen from fig. 4 that when the gas supply system of the present invention is used to supply gas, the uniformity of the surface of the wafer obtained by ion implantation is small, and the uniformity of the surface of the wafer at different dates is generally distributed near 6sigma, which indicates that when the gas supply system of the present invention is used to perform ion implantation, the gas supply system can provide stable gas flow for the ion source, and the uniformity of the surface of the wafer is greatly improved compared to when a solid source is placed in the ion source. Meanwhile, when the gas supply system disclosed by the invention is used for supplying gas to the ion source, the fluctuation of the uniformity numerical values of the surfaces of the wafers on different dates is small, namely the flow change of the gas source provided by the gas supply system on different dates is small, which shows that the uniformity of the surfaces of the wafers is greatly improved when the gas supply system disclosed by the invention is used for ion implantation, and meanwhile, the quality stability of the ion implanted wafers is greatly improved.

Further, the control device 16 is connected in communication with the first heating device 171 and the flow controller 13, respectively. The first heating device 171 can heat the reaction chamber 12 to a preset temperature under the control of the control device 16, or of course, the first heating device 171 may not be controlled by the control device 16 to heat the reaction chamber 12. The flow controller 13 may control the flow of gas into the ion source 11 to be within a predetermined range under the control of the control device 16. The flow controller 13 can control the flow rate of the gas entering the ion source 11 according to actual requirements, for example, a preset range of flow rate can be set in the control device 16, and a certain flow rate, such as 1ml/min or 2ml/min, or other suitable flow rate, can be selected within the preset range.

The control device 16 is preferably connected in communication with the pressure detection device 15, the second heating device 172 and the second temperature detection device 182. The pressure detecting means 15 is connected to the reaction chamber 12 and is configured to measure the pressure in the reaction chamber 12, so that the control means 16 controls the heating temperature of the first heating means 171 according to the pressure in the reaction chamber 12 measured by the pressure detecting means 15. The control unit 16 may also be communicatively connected to a first temperature detecting unit 181, and the first temperature detecting unit 181 is connected to the reaction chamber 12 and is configured to measure the temperature in the reaction chamber 12, so that the control unit 16 can control the heating temperature of the first heating unit 171 according to the temperature in the reaction chamber 12 measured by the first temperature detecting unit 181. Of course, the control unit 16 can also control the heating temperature of the first heating unit 171 according to the pressure in the reaction chamber 12 measured by the pressure detection unit 15 and the temperature in the reaction chamber 12 measured by the first temperature detection unit 181. The first temperature detection device 181 may not be communicatively connected to the control device 16.

In this embodiment, the control device 16 mainly controls the heating temperature of the first heating device 171 according to the pressure in the reaction chamber 12 measured by the pressure detection device 15, so that the heating temperature of the first heating device 171 is more accurately and conveniently controlled, and meanwhile, the temperature measured by the first temperature detection device 181 enables an operator to know the temperature in the reaction chamber 12 more conveniently, so as to judge the gasification degree of the solid source in the reaction chamber 12. The present application is not limited to the kind of the first temperature detecting means 181 and the pressure detecting means 15, for example, the first temperature detecting means 181 is not limited to a thermometer disposed inside the reaction chamber 12, and the pressure detecting means 15 is not limited to a vacuum gauge. In other preferred embodiments of the present invention, the first temperature detecting device 181 may also be configured as a thermocouple or other devices, and likewise, the pressure detecting device 15 may also be configured as a pressure gauge or other pressure detecting devices.

In a preferred embodiment of the present invention, the control device 16 is in communication with the second heating device 172 and the second temperature detecting device 182, respectively. The second heating device 172 and the second temperature detecting device 182 are both disposed on the gas pipeline 14. The second heating device 172 may be disposed between the reaction chamber 12 and the flow controller 13, or between the flow controller 13 and the ion source 11, and these regions may be disposed alternatively or simultaneously. The second heating device 172 is used to heat the gas line 14 to prevent the gas from freezing due to a temperature drop during its passage through the gas line 14.

In the present invention, the second heating device 172 is disposed on the gas pipeline 14, and can heat the gas flowing through the gas pipeline 14, so that the reaction chamber 12 can be installed at any position around the ion implanter as required, and the reaction chamber 12 does not have to be installed near the ion source 11 because the gas in the gas pipeline 14 is solidified, thereby saving the installation space of the machine and improving the space utilization rate around the machine.

In particular, the second temperature detecting device 182 is used for measuring the temperature in the gas pipeline 14. The control means 16 is also adapted to control the heating temperature of the second heating means 172 in dependence on the temperature in the gas line 14 measured by the second temperature detecting means 182. The position and number of the flow controllers 13 are not limited, and may be, for example, provided at the gas outlet of the reaction chamber 12, at the gas inlet of the ion source 11, or on the gas line 14, or the flow controllers 13 may be provided at these positions or at the same time. The positions and the numbers of the second heating device 172 and the second temperature detecting device 182 on the gas line 14 are not limited.

Optionally, in this embodiment, the number of the second temperature detecting devices 182 is two, one second temperature detecting device 182 is disposed between the reaction chamber and the flow controller 13, and the other second temperature detecting device 182 is disposed between the second heating device 172 and the ion source 11. The second temperature detection device 182 is arranged close to the reaction cavity 12 to obtain a first temperature value of gas flowing out of the reaction cavity 12, the other second temperature detection device 182 is arranged close to the ion source 11 to obtain a second temperature value of the gas heated by the second heating device 172, the control device 16 can adjust the heating temperature of the second heating device 172 through the first temperature value and the second temperature value at the same time, the temperature control is more accurate, and therefore the gas flowing into the ion source 11 can be accurately guaranteed not to be solidified.

To ensure more convenient control and heating of the gas in the gas line 14, in this embodiment, a flow controller 13 is provided between the reaction chamber 12 and the second heating means 172. This arrangement allows the flow controller 13 to control the flow rate of the gas generated in the reaction chamber 12 more accurately, and at the same time, the distance from the second heating device 172 to the ion source 11 can be shortened to ensure that the gas flowing into the ion source 11 is within a predetermined temperature range.

Optionally, the heating temperature of the second heating device 172 is greater than or equal to the temperature of the first heating device 171. As an alternative embodiment of the present invention, the second heating device 172 is disposed on the outer wall of the gas pipeline 14, and the first heating device 171 is disposed inside the reaction chamber 12, in this case, the second heating device 172 needs to heat the pipe wall of the gas pipeline 14 first, and then heat the gas in the pipeline through the pipe wall, and the pipe wall of the gas pipeline 14 will absorb a part of the heat, so it is preferable to set the heating temperature of the second heating device 172 to be higher than the heating temperature of the first heating device 171. Further, the second heating device 172 is disposed on the gas pipeline 14, a part of heat is lost on the gas pipeline 14 before the gas flows through the second heating device 172, the gas has a certain flow rate when flowing through the second heating device 172, and in order to allow the gas to rapidly absorb heat, it is preferable that the heating temperature of the second heating device 172 is set to be higher than that of the first heating device 171. If the solid source to be filled is indium trichloride, the heating temperature of the first heating device 171 may be set at 335-.

Specifically, in order to make the components of each part of the gas supply system simpler and more efficient, in this embodiment, the second heating device 172 is a heating belt disposed around the gas pipeline 14, the pressure detecting device 15 is a vacuum gauge disposed outside the reaction chamber 12, the first heating device 171 is a heating rod disposed inside the reaction chamber 12, and the flow controller 13 is a mass flow controller or other suitable valve capable of adjusting the opening degree. In other preferred embodiments of the present invention, the flow controller 13 is not limited to a mass flow controller, nor is the first heating device 171 limited to a heating rod. Specifically, the number and the position of the heating rods in the reaction chamber 12 are not limited, and in this embodiment, one heating rod is respectively disposed on each of the left side and the right side of the reaction chamber 12, so that the temperature of the reaction chamber 12 is rapidly increased and uniform. In another embodiment of the present invention, the first heating device 171 can also be a heating system disposed outside the reaction chamber 12, so as to control the heating temperature of the reaction chamber 12 more precisely and effectively.

When the gasification of the solid source in the reaction chamber 12 is finished, the gas supply system further comprises a gas supply device 19, the gas supply device 19 is connected with the reaction chamber 12, and the gas supply device 19 is used for conveying protective gas to the reaction chamber 12, so as to more conveniently fill the solid source. The shielding gas includes, but is not limited to, nitrogen.

In addition, the gas supply system further includes an air extractor (not shown) connected to the reaction chamber 12, and the air extractor is used for extracting air from the reaction chamber 12 to achieve a negative pressure environment.

Optionally, a first valve element 201 is disposed between the gas supply device 19 and the reaction chamber 12, and the first valve element 201 is used for controlling on/off between the gas supply device 19 and the reaction chamber 12. Preferably, a second valve 202 is provided on the gas line 14, and the second valve 202 is provided in parallel with the flow controller 13.

Preferably, the air extractor is a vacuum pump provided by the ion source 11, and the vacuum pump is connected with the gas pipeline 14; the second valve member 202 is opened and the flow controller 13 is closed when the reaction chamber 12 is evacuated by the vacuum pump for evacuating the reaction chamber 12 through the gas line 14 provided with the second valve member 202. The second valve 202 connected in parallel with the flow controller 13 is arranged, so that the second valve 202 is closed during the process of gasifying and injecting the solid source in the reaction chamber 12 into the ion source 11, and at this time, all the gas after gasifying the solid source enters the ion source 11 through the flow controller 13, and during the process of pumping the gas in the reaction chamber 12 by using the vacuum pump of the ion source 11, the second valve 202 is opened, the flow controller 13 is closed, and at this time, the pumped gas does not pass through the flow controller 13 and reaches the ion source 11 from the second valve 202, and the gas pumping step of the vacuum pump can be simplified without the gas pumping through the flow controller 13, and the pumping efficiency of the vacuum pump is improved.

In another embodiment of the present invention, the air-extracting device may be a vacuum pump additionally provided to the air supply system. In this embodiment, the ion source 11 is provided with a vacuum pump for pumping gas from the reaction chamber 12, so that when the reaction chamber 12 is filled with a solid source, the vacuum pump can be used to pump gas from the reaction chamber 12 through the gas pipeline 14, and the pumped gas is then centrally treated by a subsequent waste gas treatment device.

Optionally, the flow controller 13 is disposed on the gas line 14, the gas line 14 is provided with a third valve element 203, the third valve element 203 is disposed between the flow controller 13 and the reaction chamber 12, and the gas line 14 is provided with a fourth valve element 204, the fourth valve element 204 is disposed between the flow controller 13 and the ion source 11. Of course, the gas supply system may be provided with only the third valve element 203 or the fourth valve element 204 on the gas line 14 as needed. As an alternative embodiment of the present invention, the third valve member 203 is disposed close to the reaction chamber 12, the fourth valve member 204 is disposed close to the ion source 11, and the third valve member 203 and the fourth valve member 204 can respectively open and close the gas outlet of the reaction chamber 12 and the gas inlet of the ion source 11, so as to facilitate the isolation of the reaction chamber 12 from the ion source 11 when the reaction chamber 12 is filled with the solid source.

The invention also provides a gas supply method of the ion source, which adopts the gas supply system to supply gas to the ion source, and the gas supply method comprises the following steps:

the method comprises the following steps: placing a solid source into the reaction chamber 12;

step two: pumping the reaction cavity 12 to make the reaction cavity 12 in a negative pressure state;

step three: after the reaction chamber 12 is in a negative pressure state, the reaction chamber 12 is heated to a preset temperature by using the first heating device 171, so that the solid source is gasified;

step four: the gas generated by the gasification of the solid source flows out of the reaction chamber 12 and into the ion source 11 via the gas line 14, and in the process, the flow rate of the gas into the ion source 11 is controlled by the flow controller 13 and the gas flow rate is kept within a preset range.

In order to obtain pure solid source gasification gas from the ion source, the gasification reaction of the solid source is generally performed in a high-temperature vacuum environment. Filling the reaction chamber 12 with the solid source requires first evacuating the reaction chamber 12 so that the reaction chamber 12 is under vacuum. In this embodiment, the process of evacuating the reaction chamber 12 and gasifying the solid source is preferably as follows:

1) the first valve element 201 is closed, the second valve element 202, the third valve element 203 and the fourth valve element 204 are opened, the vacuum pump is started, and the pressure in the reaction chamber is pumped to 1E^-5Torr, thereafter, the second valve member 202, the third valve member 203 and the fourth valve member 204 are closed, in the process, the flow controller 13 can be opened or not, and the flow controller 13 is preferably closed to ensure the air exhaust efficiency;

2) after the solid source is heated to start gasification, when the pressure value of the reaction chamber 12 is 1E^-4When the Torr is near, the third valve 203 and the fourth valve 204 are opened again to allow gas to enter the gas line 14, and the flow controller 13 is used to ensure that the ion source 11 obtains a stable gas source.

Optionally, the gas supply method further includes:

when the gas flow in the gas pipeline 14 reaches a preset range, determining the current pressure in the reaction cavity 12 measured by the pressure detection device 15 at the moment as a target pressure value; in the present embodiment, the reading of the vacuum gauge when the gas flow rate in the gas line 14 reaches the preset value in the flow controller 13 is the target pressure value; it is understood that, after the solid source starts to be gasified, when the pressure value of the reaction chamber 12 reaches the target pressure value (as described above in 1E)^-4Near Torr) and then the third valve 203 and the fourth valve 204 are opened to allow the gas to enter the ion source 11 through the gas line 14, wherein the monitored gas flow rate in the gas line 14 should be within a predetermined range theoretically, and the pressure detecting device 15 is used at this timeThe measured current pressure in the reaction chamber 12 is the target pressure value (e.g., 1E)^-4Torr or near);

further, as the gasification process of the solid source proceeds, if the actual pressure value measured by the pressure detecting device 15 deviates from the target pressure value, the control device 16 may be used to adjust the heating temperature of the first heating device 171, so as to maintain the temperature in the reaction chamber 12 at the preset temperature, and thus maintain the actual flow rate of the gas within the preset range.

It should be understood that as the gasification proceeds, the residual solid content of the solid source is gradually reduced, which results in a smaller gas flow rate generated by the gasification of the solid source, and in order to ensure that the gas flow rate value in the gas pipeline 14 is not changed, the heating temperature of the reaction chamber 12 needs to be increased, so that the gasification rate of the solid source is increased to obtain more gas; meanwhile, since the rate of gas generation by the solid source is unstable, when the gas flow rate value obtained by increasing the rate of solid source gasification is higher than the initially set flow rate value at a certain moment, the gas flow rate is also unstable, and at this moment, the heating temperature of the reaction chamber 12 needs to be properly reduced to slow down the fixed source gasification rate.

In the present gas supply system, the pressure detection device 15 can measure the actual pressure value of the reaction chamber 12 in real time. The control device 16 can adjust the heating temperature of the first heating device 171 according to the actual pressure value, thereby ensuring that the flow rate of the gas entering the ion source is stable. The heating temperature of the first heating device 171 is always kept within the temperature range preset by the control device 16, i.e. the heating temperature of the first heating device 171 must not be lower than the lowest heating temperature set by the control device 16, nor higher than the highest heating temperature set by the control device 16.

Optionally, the gas supply method further includes:

when the temperature in the reaction chamber 12 reaches the set maximum temperature, if the actual pressure value of the pressure detection device 15 is lower than the target pressure value and the gas in the gas pipeline 14 has no flow, it is determined that the gasification of the solid source is finished. If the ion source requires re-use of gas at this point, a new solid source needs to be filled into the reaction chamber 12 again.

Optionally, the gas supply method further includes:

heating the gas pipeline 14 by using the second heating device 172, and detecting the actual temperature value of the gas in the gas pipeline 14 in real time by using the second temperature detecting device 181;

the heating temperature of the second heating device 172 is regulated by the control device 16 on the basis of the actual temperature value of the gas in the gas line 14.

The heating temperature of the second heating device 172 is preferably higher than the heating temperature of the first heating device 171.

Optionally, the specific process of adjusting the heating temperature of the first heating device 171 by using the control device 16 includes:

when the actual pressure value measured by the pressure detection device 15 is higher than the target pressure value, the control device 16 decreases the heating temperature of the first heating device 171; alternatively, the first and second electrodes may be,

when the actual pressure value measured by the pressure detecting means 15 is lower than the target pressure value, the control means 16 increases the temperature of the first heating means 171.

Optionally, the gas supply method further includes a fifth step, specifically including the following steps:

1) after the solid source is gasified, filling protective gas into the reaction cavity 12, and detecting the pressure in the reaction cavity 12;

2) stopping filling the protective gas when the pressure in the reaction chamber 12 reaches the target pressure;

3) after the protective gas is stopped being filled, the reaction cavity 12 is pumped, and the pumping is stopped when the pressure in the reaction cavity 12 is at the target negative pressure value;

4) repeating the steps 1) to 3) for a plurality of times to remove the residual substances (mainly residual solid source gas) in the reaction chamber 12;

5) after the substances remaining in the reaction chamber are removed, when the temperature in the reaction chamber 12 is reduced to normal temperature, the reaction chamber 12 is filled with a protective gas, so that the pressure in the reaction chamber 12 reaches a certain pressure (usually one atmosphere), and then a new solid source is filled in the reaction chamber again.

It should be understood that when the solid source in the reaction chamber 12 is completely gasified, a new solid source needs to be filled into the reaction chamber 12, and since most of the gas generated by gasifying the solid source has a certain toxicity, the solid source can be filled only after the residual solid source gasified gas in the reaction chamber 12 is pumped out and the protective gas is filled into the reaction chamber 12. In this embodiment, the preferred steps of filling the solid source are:

1) opening the first valve 201, closing the second valve 202, the third valve 203 and the fourth valve 204, filling the protective gas into the reaction chamber 12, closing the first valve 201 when the pressure value in the reaction chamber 12 reaches 500Torr, opening the second valve 202, the third valve 203 and the fourth valve 204, and closing the flow controller 13; the third valve part 203, the fourth valve part 204 and the second valve part 202 are arranged in series;

2) the reaction chamber 12 is evacuated by a vacuum pump provided in the ion source 11, and evacuation is stopped when the pressure in the reaction chamber 12 is 0.1 Torr;

3) repeating the steps 1) and 2) for more than 10 times, so that the residual solid source gas in the reaction chamber 12 can be removed completely;

4) then, when the temperature in the reaction chamber 12 is reduced to normal temperature, the inside of the reaction chamber 12 is filled with the protective gas again, and when the reading of the vacuum gauge is 760Torr, the inside of the reaction chamber 12 can be filled with a new solid source.

It should be understood that the type of the control device 16 is not particularly limited in the present invention, and may be hardware for executing Logic operation, such as a single chip, a microprocessor, a Programmable Logic Controller (PLC) or a Field-Programmable Gate Array (FPGA), or a software program, a function module, a function, an Object library (Object Libraries) or a Dynamic-Link library (Dynamic-Link Libraries) for implementing the above functions on a hardware basis. Alternatively, a combination of the above two. The person skilled in the art will know how to implement the communication between the control device 16 and the other devices on the basis of the disclosure of the present application. In addition, the control device 16 is a preferred embodiment of the present invention, and those skilled in the art can adopt other technical means, such as manual control and mechanical control, to achieve the same technical effects.

In summary, the gas supply system and the gas supply method of the ion source provided by the invention have the advantages that the stable gas supply system is arranged at the front end of the ion source, so that the solid source gasified gas can obtain stable gas flow when entering the ion source, and the subsequent ion implantation process can be better completed after the stable gas flow enters the ion source, so that the better implantation effect can be obtained when the wafer is subjected to ion implantation. Meanwhile, the stable and efficient gas supply can also improve the ion implantation productivity of the wafer. In the traditional solid source gasification, a solid source is placed in an ion source, the ion source needs to be maintained after the solid source is gasified every time, because the ion source can only contain less solid sources, the ion source often needs to be maintained in advance before the due maintenance period of the ion source is reached, a gas supply device can be isolated from the ion source when the gas supply system is used for filling the solid source, the maintenance period of the ion source is prolonged, and the service life of the ion source can also be prolonged.

The preferred embodiments of the present invention are described above, but not limited to the ranges disclosed in the above embodiments, for example, the temperature and pressure values disclosed above are set according to the type of solid source, but not limited to the ranges, wherein the temperature and pressure values disclosed in the present invention are mainly described for the indium trichloride solid source.

The above description is only for the purpose of describing the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention, and any variations and modifications made by those skilled in the art based on the above disclosure are within the scope of the present invention.