阅读说明：本技术 外延生长装置 (Epitaxial growth device ) 是由 三重野文健 于 2021-05-13 设计创作，主要内容包括：本发明提供了外延生长装置,其特征在于包括反应腔室和真空锁,反应腔室具有若干个加热器排列成圆圈,反应腔室具有进气和排气通路,反应腔室还设有分隔装置能够喷出气体来屏蔽每个加热器,反应腔室还设有晶圆装卸器装卸加热器上的晶圆；真空锁中具有晶圆匣用于运送晶圆。本发明提高了外延工艺的产能通量。(The invention provides an epitaxial growth device, which is characterized by comprising a reaction chamber and a vacuum lock, wherein the reaction chamber is provided with a plurality of heaters which are arranged into a circle, the reaction chamber is provided with an air inlet passage and an air outlet passage, the reaction chamber is also provided with a separating device which can spray air to shield each heater, and the reaction chamber is also provided with a wafer loading and unloading device which loads and unloads wafers on the heaters; the vacuum lock has a wafer cassette therein for transporting wafers. The invention improves the productivity flux of the epitaxial process.)

1. The epitaxial growth device is characterized by comprising a reaction chamber and a vacuum lock, wherein the reaction chamber is provided with a plurality of heaters which are arranged into a circle, the reaction chamber is provided with an air inlet passage and an air outlet passage, the reaction chamber is also provided with a separating device which can spray air to shield each heater, and the reaction chamber is also provided with a wafer loader for loading and unloading wafers on the heaters; the vacuum lock has a wafer cassette therein for transporting wafers.

2. Epitaxial growth apparatus according to claim 1 wherein the heater is a silicon carbide coated graphite resistance heater, the heater being cylindrical in shape and flat at the top.

3. The epitaxial growth apparatus of claim 1 wherein the heater top has a recess for receiving the wafer, the recess being shaped to have a depth profile that approximates an arc.

4. An epitaxial growth apparatus according to claim 3 wherein the heater is provided with a plurality of holes in the recessed portion through which the pins can be moved up and down to lift or lower the wafer.

5. An epitaxial growth apparatus according to claim 1 wherein the cross-sectional area of the bottom of the heater is the largest and becomes smaller from bottom to top.

6. Epitaxial growth apparatus according to claim 1 wherein the gas ejected by the separation means is hydrogen or one or a combination of argon or helium.

7. Epitaxial growth apparatus according to claim 1, characterised in that the exhaust passage is located between the heaters.

8. Epitaxial growth apparatus according to claim 1 wherein the housing of the reaction chamber is a water cooled wall chamber having silicon carbide coated with a graphite layer on the inner wall.

9. Epitaxial growth apparatus according to claim 1 wherein the gas inlet passage is an inverted funnel shaped gas diffuser for introducing source gas into the wafer directly below.

10. The epitaxial growth apparatus of claim 1, wherein the wafer handler is radially extendable and retractable corresponding to the number of matched heaters; during shrinkage, the wafer handler is positioned between the heaters; in the process of loading and unloading the wafers, the wafer loader-unloader rotates to extend into the corresponding heater position to unload the original wafer, then rotates the position of one heater to load the taken-out wafer onto the position of the next heater.

11. Epitaxial growth apparatus according to claim 1, characterized in that the wafer handler is provided with a wafer holding chuck or a wafer fork or a bernoulli chuck at its bottom.

12. Epitaxial growth apparatus according to claim 1, characterized in that the sides of the wafer handler are made of porous material or are provided with holes enabling to eject gases to shield different gases from the byproduct deposits.

13. An epitaxial growth apparatus according to claim 1 wherein the reaction chamber has four heaters arranged in a circle and the vacuum lock has a cassette.

14. An epitaxial growth apparatus according to claim 1 wherein the reaction chamber has six heaters arranged to define a circle and two wafer cassettes are arranged in the vacuum lock.

15. The epitaxial growth apparatus of claim 1 wherein the reaction chamber has two, six heaters per reaction chamber surrounding a circle, and three wafer cassettes in the vacuum lock.

16. The epitaxial growth apparatus of claim 1 wherein the reaction chamber has two, six heaters per reaction chamber surrounding a circle, and three wafer cassettes in the vacuum lock.

17. An epitaxial growth apparatus according to any one of claims 14 to 16 wherein a pre-treatment chamber is provided between the reaction chamber and the vacuum lock.

18. Epitaxial growth apparatus according to claim 1 wherein the reaction chamber has three heaters per reaction chamber; the three reaction chambers are enclosed into three surfaces, and the other surface is provided with three wafer boxes in a vacuum lock mode; the mechanical arm is enclosed in the middle and is provided with two mechanical arms, and two wafers can be loaded and unloaded from one reaction chamber at a time.

Technical Field

The invention relates to the field of semiconductor technology and equipment, in particular to an epitaxial growth device.

Background

The reaction chambers for silicon and silicon carbide are conceptually identical, with the difference being the growth temperature and the addition of gas as a source of carbon.

From the history of silicon epitaxial process, there are three main types of devices: the early reaction apparatus utilizing radio frequency heating, the reaction apparatus utilizing infrared lamp heating, and the recently developed leaf-type high-speed rotary reaction apparatus utilizing resistance heating. In any reaction apparatus, the basic structure thereof comprises: the wafer processing device comprises a quartz cavity with a gas inlet and a gas outlet, a wafer tray and a heating device.

One specific conventional silicon epitaxial reactor employs a single wafer processing concept, as disclosed in japanese patent laid-open No. 63-222427, and is provided with a silicon carbide-coated graphite heater, a silicon carbide-coated graphite gas diffuser, and a vertical gas diffusion path. Referring to FIG. 1, FIG. 1 is a schematic view of Sho 63-222427. In the figure, a bell jar 6 forms a reaction chamber, a heated object 7, i.e., a wafer, is placed on a support tray 1, and the support tray 1 has a conductive part 2 for heating the wafer, and the conductive part 2 is connected with an electrode 3, a control circuit 4, and a heating power source 5 in this order to form a heating circuit. The reactor of fig. 1 can only be autodoped very slowly due to the concept of a monolithic process.

Similarly, the silicon carbide epitaxial reaction devices on the market at present are not of various types, and the performance parameters are not ideal. The problem is mainly reflected in low energy flux, and the processing efficiency of the silicon carbide epitaxial reaction device on the market at present is generally 10 microns thick per month when the silicon carbide epitaxial reaction device grows on a 1500-2500 wafer.

Disclosure of Invention

The present invention has been made in view of the above problems, and an object of the present invention is to provide an epitaxial growth apparatus for high throughput.

The invention provides an epitaxial growth device for achieving the purpose, which comprises a reaction chamber and a vacuum lock, wherein the reaction chamber is provided with a plurality of heaters which are arranged in a circle, the reaction chamber is provided with an air inlet passage and an air outlet passage, the reaction chamber is also provided with a separating device which can spray air to shield each heater, and the reaction chamber is also provided with a wafer loading and unloading device which loads and unloads wafers on the heaters; the vacuum lock has a wafer cassette therein for transporting wafers.

The heater is a silicon carbide coated graphite resistance heater that is cylindrical in shape and flat at the top. The top of the heater is provided with a concave part for placing a wafer, and the shape of the concave part is that the depth profile is approximate to an arc line. The heater is provided with a plurality of holes in the concave part, and the thimble can move up and down through the holes so as to support or lower the wafer. The sectional area of the bottom of the heater is the largest and gradually becomes smaller from bottom to top.

The gas sprayed by the separation device is hydrogen or one or a combination of argon or helium. The exhaust passage is located between the heaters. The shell of the reaction chamber is a water-cooled wall chamber, and the inner wall of the cavity is silicon carbide coated with a graphite layer. The gas inlet passage is an inverted funnel-shaped gas diffuser for introducing the source gas into the wafer directly below.

The wafer loader can radially extend and retract, and the number of the heaters is correspondingly matched; during shrinkage, the wafer handler is positioned between the heaters; in the process of loading and unloading the wafers, the wafer loader-unloader rotates to extend into the corresponding heater position to unload the original wafer, then rotates the position of one heater to load the taken-out wafer onto the position of the next heater. The wafer handler has a wafer-holding chuck or a wafer fork or a bernoulli chuck at its bottom. The sides of the wafer handler are made of a porous material or are provided with holes to enable the ejection of gases to shield the different gases from byproduct deposits.

The reaction chamber has four heaters enclosing a circle, and a wafer cassette is arranged in the vacuum lock. Or the reaction chamber is provided with six heaters which form a circle, and two wafer boxes are arranged in the vacuum lock. Or the reaction chamber has two reaction chambers, each reaction chamber has six heaters which surround to form a circle, and the vacuum lock has three wafer boxes. Or two reaction chambers are provided, each reaction chamber is provided with six heaters to form a circle, and three wafer boxes are arranged in the vacuum lock.

Furthermore, a pretreatment chamber is arranged between the reaction chamber and the vacuum lock.

Preferably, the reaction chamber has three, two heaters per reaction chamber; the three reaction chambers are enclosed into three surfaces, and the other surface is provided with three wafer boxes in a vacuum lock mode; the mechanical arm is enclosed in the middle and is provided with two mechanical arms, and two wafers can be loaded and unloaded from one reaction chamber at a time.

The invention has the beneficial effect of solving the problem that the existing silicon carbide epitaxial reaction device on the market has unsatisfactory performance parameters. The productivity flux is high, the invention adopts a plurality of epitaxial layer linear reaction chambers with double rows, the growth rate is 1.5 microns per minute, and the productivity can reach 3600 wafers per month. Because the invention adopts multilayer epitaxial growth, the invention is suitable for carrying out the process steps of doping, deposition and the like on a plurality of layers, and can better control the process quality.

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic diagram of the prior art;

FIG. 2 is a schematic structural diagram of an epitaxial growth apparatus according to the present invention;

FIG. 3 is a cross-sectional view of an epitaxial growth apparatus of the present invention;

FIG. 4 is a schematic structural diagram of one embodiment of the present invention;

FIG. 5 is a schematic view of another embodiment of the present invention;

FIG. 6 is a schematic view of yet another embodiment of the present invention;

FIG. 7 is a schematic view of yet another embodiment of the present invention;

figure 8 is a schematic view of an embodiment of the present invention incorporating a robotic arm.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

The present invention is described in further detail below to enable those skilled in the art to practice the invention with reference to the description.

Referring to fig. 2, fig. 2 is a schematic structural diagram of an epitaxial growth apparatus according to the present invention. As shown in fig. 2, the epitaxial growth apparatus is composed of a reaction chamber 201 and a vacuum lock 202, one reaction chamber 201 has a plurality of heaters 203 arranged in a circle, wherein the reaction chamber 201 has a plurality of heaters 203 operating under normal pressure or reduced pressure. A partition device 204 is arranged above or between the heaters 203 and can spray gas, such as hydrogen gas or argon gas or helium gas, so as to shield and isolate each heater 203; the reaction chamber 201 is also provided with an exhaust 205 located between the heaters 203. A wafer cassette 206 is disposed in the vacuum lock 202 for transporting wafers to be processed or processed.

For a further understanding of the structure of the present invention, please refer to fig. 3, wherein fig. 3 is a cross-sectional view of the epitaxial growth apparatus of the present invention. The shell of the reaction chamber 201 is a water-cooled wall chamber, and the inner wall 209 of the cavity is silicon carbide coated with a graphite layer. The reaction chamber 201 is further provided with a wafer handler 207, the wafer handler 207 being radially retractable corresponding to the number of matched heaters 203, the wafer handler 207 being located between the heaters 203. During heating, the wafer handler 207 retracts. During the process of loading and unloading the wafer 301, the wafer loader 207 extends into the corresponding heater position to unload the original wafer 301 and rotates one heater position to load the wafer onto the next heater position. The partition 204 and the wafer handler 207 may rotate about the center of the reaction chamber 201.

The top of the stainless steel chamber housing with water cooling is provided with a source gas inlet, and a reversed funnel-shaped gas diffuser 208 is used to introduce the source gas into the wafer 301 directly below. The inner chamber wall 209 is made of graphite coated with silicon carbide. Below the gas diffuser 208 is a silicon carbide coated graphite heater 203. On top of the heater 203 is placed a wafer 301. The spacers 204 between the heaters 203 have several gas outlets 210 to enable the ejection of gas, such as hydrogen or argon or helium, to shield each heater 203. Gases, such as hydrogen, helium, and argon, are exhausted from the exhaust pipe 205 at the bottom of the chamber through a vertical gas flow channel formed around the heater 203.

The wafer handler 207 is provided with a wafer clamping chuck or a wafer fork or a bernoulli chuck at its bottom; the wafer-holding chuck or wafer fork is used for atmospheric or reduced pressure processes, while the bernoulli chuck is used for atmospheric or low pressure processes, optionally made of porous material on the side of the wafer handler 207, such as silicon, silicon carbide, carbon graphite, ceramic, etc. capable of ejecting gas, or the side of the wafer handler 207 is provided with several gas outlets 210 capable of ejecting gas to shield different gases from generating byproduct deposits.

The heater 203 is a graphite resistance heater coated with silicon carbide, and the heater 203 is cylindrical in shape and flat at the top and has a recess for placing the wafer 301, and the recess is shaped such that the depth profile is approximately curved. The heater is provided with three holes in the concave part, and the thimble can move up and down through the holes so as to support or lower the wafer. The number of holes can be adjusted according to different needs.

Referring to fig. 4, fig. 4 is a schematic structural diagram of an embodiment of the present invention. In fig. 4, six heaters 203 are enclosed in the reaction chamber 201 in this embodiment as a circle. The vacuum lock 202 has a wafer cassette 206 therein. Spacers 204 radiating from the center of the reaction chamber 201 are positioned between and separate the heaters 203. The retractable wafer handler 207 retracts above the isolation device 204. When handling wafers, it can be rotated to a position opposite to heater 203 and extended above heater 203 to handle wafers in its position. The partition 204 and the wafer handler 207 may rotate about the center of the reaction chamber 201.

Referring to fig. 5, fig. 5 is a schematic diagram of another embodiment of the invention. In the embodiment of fig. 5, six heaters 203 are enclosed in the reaction chamber 201 to form a circle. Having two wafer cassettes 206 in the vacuum lock 202 greatly improves processing efficiency.

Referring to fig. 6, fig. 6 is a schematic diagram illustrating another embodiment of the present invention. Unlike the embodiment of fig. 5, this embodiment adds a pre-processing chamber 302 between the vacuum lock 202 and the reaction chamber 201. Because the gas, temperature, and time conditions for the pre-treatment and each epitaxial growth are different, the separation of the pre-treatment chamber 302 from the reaction chamber 201 makes the apparatus simpler and more convenient to process. The pre-processing chamber 302 also has separate heating and gas inlet and exhaust systems.

In the embodiment of fig. 7, the number of reaction chambers 201 is further increased to two, and six heaters 203 are enclosed in each reaction chamber 201 to form a circle. There are three wafer cassettes 206 in the vacuum lock 202. A pre-treatment chamber 302 is disposed between each reaction chamber 201 and the vacuum lock 202. This further improves the processing efficiency.

Figure 8 is a schematic view of an embodiment of the present invention incorporating a robotic arm. In fig. 8, three reaction chambers 201 are enclosed on three sides, and the other side is a vacuum lock 202. There are two heaters 203 in each reaction chamber 201. There are three wafer cassettes 206 in the vacuum lock 202. The robot has two robots that load and unload two wafers at a time from one reaction chamber 201.

The epitaxial growth process mentioned in the present invention is one of silicon carbide or gallium nitride or silicon germanium. The number of vacuum locks and corresponding reaction chambers can be increased according to the optimization requirements of the production capacity.

The multilayer epitaxial process comprises the steps of carrying out multi-step silicon carbide epitaxial growth in a plurality of reaction cavities, sequentially arranging the reaction cavities, preprocessing the first reaction cavity, and carrying out primary epitaxial growth on the rest reaction cavities.

In the multi-step epitaxial growth process in the reaction chambers, the idle reaction chambers are cleaned by a dry method by adopting one formula of hydrogen chloride/hydrogen or chlorine trifluoride/hydrogen, argon, helium or hydrogen chloride/chlorine trifluoride/hydrogen, argon and helium. The epitaxial process is one of silicon carbide or gallium nitride or silicon germanium. The atmosphere gas of the pretreatment is hydrogen or hydrogen chloride. After the pretreatment, the wafers were processed in a subsequent reaction chamber for 18 minutes, in which the wafers were epitaxially grown for 15 minutes. In each reaction cavity for epitaxy, the source gas is composed of silane, propane, hydrogen and nitrogen; the reaction temperature is 1580 ℃ and the pressure is about 60 torr; the silane gas flow rate was 500sccm (milliliters per minute under standard conditions), the propane gas flow rate was 200sccm (milliliters per minute under standard conditions), the hydrogen gas flow rate was 150slm (liters per minute under standard conditions), and the nitrogen gas flow rate was 25sccm (milliliters per minute under standard conditions).

While embodiments of the invention have been disclosed above, it is not intended to be limited to the uses set forth in the specification and examples. It can be applied to all kinds of fields suitable for the present invention. Additional modifications will readily occur to those skilled in the art. Therefore, the invention is not to be limited to the specific details and illustrations shown and described herein, without departing from the general concept defined by the claims and their equivalents.