阅读说明：本技术 晶圆清洗干燥方法及晶圆清洗干燥装置 (Wafer cleaning and drying method and wafer cleaning and drying device ) 是由 黄立佐 张修凯 许明哲 于 2019-11-08 设计创作，主要内容包括：本揭示提供一种晶圆清洗干燥方法及晶圆清洗干燥装置。晶圆清洗干燥方法包含下列步骤：提供储有清洗液的清洗槽、将晶圆竖直地浸入清洗液内、持续注入清洗液使多余的清洗液自清洗槽上方的溢流口流出、使清洗液以慢速排水模式自下方排水口排出、当清洗液的液面下降至晶圆上方时关闭排水口、以二阶段方式注入液态挥发性溶剂于液面以形成二液相层、再次开启排水口以慢速排水模式排出清洗液、当液态挥发性溶剂的液面低于晶圆的最低位置时以快速排水模式排出清洗液、以及自清洗槽的上方导入高温氮气以吹干所述晶圆。(The present disclosure provides a wafer cleaning and drying method and a wafer cleaning and drying apparatus. The wafer cleaning and drying method comprises the following steps: providing a cleaning tank with cleaning liquid stored therein, vertically immersing a wafer in the cleaning liquid, continuously injecting the cleaning liquid to make redundant cleaning liquid flow out from an overflow port above the cleaning tank, discharging the cleaning liquid from a lower water outlet in a slow water discharge mode, closing the water outlet when the liquid level of the cleaning liquid is lowered to the upper part of the wafer, injecting liquid volatile solvent into the liquid level in a two-stage mode to form a two-phase layer, opening the water outlet again to discharge the cleaning liquid in the slow water discharge mode, discharging the cleaning liquid in the fast water discharge mode when the liquid level of the liquid volatile solvent is lower than the lowest position of the wafer, and introducing high-temperature nitrogen gas from the upper part of the cleaning tank to dry the wafer.)

1. A wafer cleaning and drying method is characterized by comprising the following steps:

providing a cleaning tank with cleaning fluid stored therein;

vertically immersing a wafer into the cleaning solution;

continuously injecting the cleaning solution from a water inlet below the cleaning tank so as to enable the redundant cleaning solution to flow out from an overflow port above the cleaning tank;

closing the water inlet and opening a water outlet at the bottom of the cleaning tank to discharge the cleaning solution in a slow water discharge mode;

when the liquid level of the cleaning solution is lowered to the position above the wafer, closing the water outlet of the cleaning tank;

injecting a liquid volatile solvent into the liquid surface of the cleaning solution in a two-stage manner to form a two-phase layer;

opening the water outlet again, and discharging the cleaning solution in the slow water discharging mode;

when the liquid level of the liquid volatile solvent is lower than the lowest position of the wafer, discharging the cleaning liquid in a quick drainage mode; and

introducing high-temperature nitrogen from the upper part of the cleaning tank to dry the wafer;

wherein the step of injecting the liquid volatile solvent in the two-stage manner comprises:

initially injecting the liquid volatile solvent such that the liquid volatile solvent has a first height;

standing the liquid volatile solvent; and

and injecting the liquid volatile solvent again to enable the liquid volatile solvent to reach a second height.

2. The wafer drying method of claim 1, wherein the liquid volatile solvent has the first height between 5mm and 6mm, and the liquid volatile solvent has the second height between 10 mm and 15 mm.

3. The wafer drying method as claimed in claim 1, wherein the flow rate of the slow draining mode is between 3.5L/M and 5L/M.

4. The method of claim 1, wherein a flow rate of the high temperature nitrogen gas is between 380L/M and 430L/M when the high temperature nitrogen gas is introduced to dry the wafer.

5. The method as claimed in claim 1, further comprising a pumping step of pumping out the high temperature nitrogen gas through a pumping system at the bottom of the cleaning tank at a pumping pressure between 60 Pa and 90Pa when the high temperature nitrogen gas is introduced from the top of the cleaning tank to dry the wafer.

6. The method of claim 1, wherein the cleaning solution is heated deionized water and the liquid volatile solvent is liquid isopropyl alcohol.

7. A wafer cleaning and drying apparatus, comprising:

the cleaning tank is provided with a water inlet arranged at the lower part, an overflow port arranged at the upper part and a water outlet arranged at the bottom;

the bracket is arranged in the cleaning tank to vertically bear the wafer; and

a liquid volatile solvent introduction pipe for introducing the liquid volatile solvent from the periphery of the upper part of the cleaning tank.

8. The apparatus for cleaning and drying a wafer as claimed in claim 7, wherein a flow guiding plate is further disposed above the cleaning tank, and the flow guiding plate is used to guide the liquid volatile solvent to be directly injected into the surface of the cleaning solution after the liquid volatile solvent flows out of the liquid volatile solvent introducing pipeline.

9. The apparatus according to claim 7, further comprising a pumping system disposed at the bottom of the cleaning tank.

10. The apparatus according to claim 7, wherein the cleaning solution is heated deionized water, and the liquid volatile solvent is liquid isopropyl alcohol.

[ technical field ] A method for producing a semiconductor device

The present disclosure relates to cleaning and drying methods and cleaning and drying apparatuses, and more particularly, to a wafer cleaning and drying method and a wafer cleaning and drying apparatus.

[ background of the invention ]

In the prior art, after the wafer is cleaned by the wet process, the wafer needs to be dried immediately for the subsequent process.

In detail, since the finished products of the wafers after processing are all in nanometer grade, the particles or chemicals remained on the wafer surface during the processing process can seriously affect the yield of the finished products of the wafers, and need to be effectively removed from the wafer surface.

When the wafer is cleaned by a wet process, the wafer is immersed in the cleaning solution of the cleaning tank, and the residual particles or chemicals are removed by the cleaning solution, and the cleaned wafer needs to be dried effectively for the subsequent process.

Therefore, it is an urgent need in the art to complete the cleaning and drying of the wafer in the shortest time.

[ summary of the invention ]

An object of the present disclosure is to provide a wafer cleaning and drying method and a wafer cleaning and drying apparatus, which can effectively remove particles or chemicals remaining on a wafer and shorten the time for drying the wafer, thereby completing the cleaning and drying of the wafer in a shortest time.

To achieve the above object, the present invention provides a wafer cleaning and drying method, comprising the steps of:

providing a cleaning tank with cleaning fluid stored therein;

vertically immersing the wafer into the cleaning solution;

cleaning liquid is injected into the water inlet below the continuous self-cleaning groove, so that redundant cleaning liquid flows out from the overflow port above the self-cleaning groove;

closing the water inlet and opening a water outlet at the bottom of the cleaning tank to discharge the cleaning solution in a slow water discharge mode;

when the liquid level of the cleaning solution drops to the upper part of the wafer, closing the water outlet of the cleaning tank;

injecting liquid volatile solvent into the liquid surface of the cleaning solution in a two-stage mode to form a two-phase layer;

opening the water outlet again, and discharging the cleaning solution in a slow water discharging mode;

when the liquid level of the liquid volatile solvent is lower than the lowest position of the wafer, discharging the cleaning liquid in a quick drainage mode; and

introducing high-temperature nitrogen gas from the upper part of the self-cleaning tank to blow and dry the wafer;

wherein, the step of injecting the liquid volatile solvent in the two-stage mode comprises the following steps:

injecting a liquid volatile solvent for the first time so that the liquid volatile solvent has a first height;

standing the liquid volatile solvent; and

and injecting the liquid volatile solvent again to enable the liquid volatile solvent to reach a second height.

In the wafer cleaning and drying method disclosed by the invention, the liquid volatile solvent has a first height between 5 and 6mm, and the liquid volatile solvent has a second height between 10 and 15 mm.

In the wafer cleaning and drying method disclosed by the invention, the flow rate of the slow drainage mode is between 3.5L/M and 5L/M.

In the wafer cleaning and drying method, when high-temperature nitrogen is introduced to dry the wafer, the flow rate of the high-temperature nitrogen is between 380L/M and 430L/M.

In the method for cleaning and drying a wafer, when high-temperature nitrogen is introduced from the top of the cleaning tank to dry the wafer, the method further comprises an air-extracting step of synchronously extracting the high-temperature nitrogen through an air-extracting system at the bottom of the cleaning tank, wherein the air-extracting pressure of the air-extracting system is between 60 and 90 Pa.

In the method for cleaning and drying a wafer, the cleaning solution is heated deionized water, and the liquid volatile solvent is liquid isopropyl alcohol.

To achieve the above object, the present disclosure provides a wafer cleaning and drying apparatus including a cleaning tank, a support, and a liquid volatile solvent introduction pipe. The cleaning tank is internally stored with cleaning fluid and is provided with a water inlet arranged at the lower part, an overflow port arranged at the upper part and a water outlet arranged at the bottom. The bracket is arranged in the cleaning tank to vertically bear the wafer. The liquid volatile solvent introduction line is used for introducing the liquid volatile solvent from the periphery above the cleaning tank.

In the wafer cleaning and drying device, the drainage plate is further arranged above the cleaning tank, and after the liquid volatile solvent flows out of the liquid volatile solvent introduction pipeline, the drainage plate is used for guiding the liquid volatile solvent to be directly injected into the liquid level of the cleaning liquid.

The wafer cleaning and drying device further comprises an air pumping system which is arranged at the bottom of the cleaning tank.

In the wafer cleaning and drying apparatus of the present disclosure, the cleaning solution is heated deionized water, and the liquid volatile solvent is liquid isopropyl alcohol.

In order to make the aforementioned and other aspects of the present disclosure more comprehensible, preferred embodiments accompanied with figures are described in detail below:

[ description of the drawings ]

FIG. 1 is a step diagram of a wafer cleaning and drying method according to the present disclosure.

FIG. 2 is a diagram illustrating a two-stage process of injecting a liquid volatile solvent into a wafer during a wafer cleaning and drying method according to the present disclosure.

Fig. 3 to 11 are schematic views corresponding to the flow of fig. 1.

Fig. 12 to 13 are schematic views illustrating a drainage plate disposed above a cleaning tank in the wafer cleaning and drying apparatus of the present disclosure.

[ detailed description ] embodiments

In order to make the aforementioned and other objects, features and advantages of the present disclosure comprehensible, preferred embodiments accompanied with figures are described in detail below. Furthermore, directional phrases used in this disclosure, such as, for example, upper, lower, top, bottom, front, rear, left, right, inner, outer, lateral, peripheral, central, horizontal, lateral, vertical, longitudinal, axial, radial, uppermost or lowermost, etc., refer only to the orientation of the attached drawings. Accordingly, the directional terms used are used for the purpose of illustration and understanding of the present disclosure, and are not used to limit the present disclosure.

In the drawings, elements having similar structures are denoted by the same reference numerals.

The present disclosure relates to a wafer cleaning and drying method and a wafer cleaning and drying apparatus, which can effectively remove particles or chemicals remaining on a wafer and shorten the time for drying the wafer, thereby completing the cleaning and drying operations of the wafer in a shortest time.

In the drawings, fig. 1 is a step diagram of a wafer cleaning and drying method according to the present disclosure. Fig. 2 to 11 are schematic views corresponding to the steps of fig. 1.

In detail, as shown in fig. 1, a wafer cleaning and drying method of the present disclosure includes the following steps:

s1: a cleaning tank storing a cleaning liquid is provided.

As shown in FIG. 3, a cleaning tank 110 with a cleaning solution 200 stored therein is provided, and the cleaning solution 200 is injected from a water inlet 112 at the lower part of the cleaning tank 110.

S2: the wafer is vertically immersed in the cleaning solution.

As shown in fig. 4, after the cleaning solution 200 in the cleaning tank 110 is filled to a certain height, the wafer 300 is vertically immersed in the cleaning solution 200, such that the wafer 300 is carried by the support 120 and the wafer 300 is completely immersed in the cleaning solution 200.

S3: and cleaning liquid is injected into the water inlet below the continuous self-cleaning tank, so that redundant cleaning liquid flows out from the overflow port above the cleaning tank.

Referring to fig. 5, when the wafer 300 is vertically immersed in the cleaning solution 200 and the wafer 300 is completely immersed in the cleaning solution 200, the cleaning solution 200 is continuously injected from the water inlet 112 below the cleaning tank 110 to clean the wafer 200. In this way, the cleaning solution 200 with particles or chemicals after the wafer 200 is cleaned is pushed by the cleaning solution 200 newly injected below the cleaning tank 110 to become an excessive cleaning solution 200, and then flows out from the overflow port 114 above the cleaning tank 110.

That is, particles or chemicals remaining on the surface of the wafer 300 during wafer processing can be effectively removed at this stage.

Since the wafer 300 has other subsequent processing steps after the cleaning operation is completed, the cleaned wafer 300 needs to be dried quickly to ensure that the subsequent processing steps can be performed smoothly. Thus, the insertion is illustrative of the subsequent drying step:

s4: the water inlet is closed, and the water outlet at the bottom of the cleaning tank is opened, so that the cleaning liquid is discharged in a slow water discharge mode.

As shown in FIG. 6, since the wafer 300 has effectively removed the particles or chemicals remaining on the surface of the wafer 300 in the above steps, after the water inlet 112 is closed, the water outlet 116 at the bottom of the cleaning tank 110 is opened, so that the cleaning solution 200 is drained from the bottom of the cleaning tank 110 in a slow drainage mode.

S5: when the liquid level of the cleaning liquid drops to the upper part of the wafer, the water outlet of the cleaning tank is closed.

Next, as shown in fig. 7, when the cleaning solution 200 is drained from the bottom of the cleaning tank 110 in the slow drain mode and the liquid level of the cleaning solution 200 is lowered to above the wafer 300, the drain 116 of the cleaning tank 110 is closed.

S6: injecting liquid volatile solvent into the liquid surface of the cleaning solution in a two-stage manner to form a two-phase layer.

As shown in fig. 8, after the liquid level of the cleaning solution 200 is lowered to above the wafer 300 and the drain 116 of the cleaning tank 110 is closed, the liquid volatile solvent 400 is injected into the liquid level of the cleaning solution 200 in a two-stage manner to form a two-phase layer.

S7: the drain port is opened again and the cleaning solution is drained in a slow drain mode.

As shown in fig. 9, after the two-phase layer is formed, the drain 116 is opened again, and the cleaning solution 200 is drained in the slow drain mode. In this way, during the slow discharge of the cleaning solution 200, the liquid volatile solvent 400 can completely contact the wafer 300 from top to bottom and gradually volatilize. Since the liquid volatile solvent 400 will carry away the water and impurities remaining on the wafer 300 during the evaporation process, this step will surely complete the drying operation of the wafer 300.

S8: when the liquid level of the liquid volatile solvent is lower than the lowest position of the wafer, the cleaning liquid is discharged in a fast drainage mode.

Next, as shown in fig. 10, when the liquid level of the liquid volatile solvent 400 is lower than the lowest position of the wafer 300, it means that the liquid volatile solvent 400 is fully spread on the surface of the wafer 300 and is no longer influenced by the cleaning solution 200, so that the cleaning solution 200 can be drained from the cleaning tank 110 in a fast draining mode, thereby facilitating the subsequent operation of removing the wafer 300 from the cleaning tank 110.

S9: high temperature nitrogen is introduced from the top of the cleaning tank to dry the wafer.

Finally, as shown in fig. 11, after the cleaning solution 200 is completely exhausted from the cleaning tank 110, a high temperature nitrogen gas 500 may be introduced from above the cleaning tank 110 to accelerate the volatilization of the liquid volatile solvent 400 to dry the wafer 300.

Wherein, at S6: the step of injecting the liquid volatile solvent 400 in the two-stage manner may further include the steps of:

s61: the liquid volatile solvent is initially injected such that the liquid volatile solvent has a first height.

S62: standing the liquid volatile solvent; and

s63: and injecting the liquid volatile solvent again to enable the liquid volatile solvent to reach a second height.

In detail, as shown in fig. 12, since the liquid surface of the cleaning solution 200 is not uniformly turbid in the initial process of injecting the liquid volatile solvent 400 to the liquid surface of the cleaning solution 200, only a small amount of the liquid volatile solvent 400 having the first height H1 is injected first in the stage S61.

Next, as shown in step S62, the liquid volatile solvent 400 is left standing for a first time to make the cleaning solution 200 and the liquid volatile solvent 400 present an initial two-phase layer, and then as shown in fig. 13 and step S63, the liquid volatile solvent 400 is injected again to make the liquid volatile solvent 400 reach the second height H2.

At this time, since the liquid volatile solvent 400 is already above the initial two-phase layer after the standing in step S62, the liquid volatile solvent 400 injected again in step S63 does not contact the liquid surface of the cleaning liquid 200, and thus the occurrence of the turbidity phenomenon can be avoided, and the waiting time for standing the liquid volatile solvent 400 can be shortened.

In other words, in the present disclosure, the step of injecting the liquid volatile solvent 400 in a two-stage manner is used to shorten the waiting time required for the standing process after the liquid volatile solvent is injected to the liquid level of the cleaning solution in the prior art, thereby improving the working efficiency of the method for cleaning and drying the wafer.

In the wafer cleaning and drying method of the present disclosure, the first height H1 of the liquid volatile solvent 400 injected in the first stage is between 5mm and 6mm, which can prevent the liquid volatile solvent 400 injected in the second stage from contacting the cleaning solution 200, thereby effectively avoiding the turbidity phenomenon. After the liquid volatile solvent 400 is injected in the second stage, the liquid volatile solvent 400 has a second height H2 (i.e., the total height) of 10-15 mm, so as to ensure that a sufficient amount of the liquid volatile solvent 400 can contact the wafer 300 during the process of contacting the wafer 300 from top to bottom and gradually volatilizing in step S7 shown in fig. 9.

In the wafer cleaning and drying method disclosed by the invention, the flow rate of the slow drainage mode is between 3.5L/M and 5L/M. This flow rate ensures that the liquid levels of the cleaning solution 200 and the liquid volatile solvent 400 are maintained to be gradually lowered during the draining process, so that the liquid volatile solvent 400 contacts the wafer 300 and is volatilized therewith.

In the wafer cleaning and drying method of the present disclosure, when the high temperature nitrogen 500 is introduced to dry the wafer 300, the flow rate of the high temperature nitrogen 500 is between 380L/M and 430L/M. Moreover, when the high temperature nitrogen 500 is introduced from the top of the cleaning tank 110 to dry the wafer 300, an air-extracting step is further included, wherein the high temperature nitrogen 500 is synchronously extracted by the air-extracting system 140 at the bottom of the cleaning tank 110, and the air-extracting pressure of the air-extracting system 140 is between 60 Pa and 90 Pa.

The drying operation of the wafer 300 can be accelerated by introducing the high temperature nitrogen 500, and the use of the pumping system 140 is helpful to rapidly exhaust the gas with moisture or other impurities after the liquid volatile solvent 400 is volatilized, so as to avoid polluting the wafer 300 again.

In the preferred embodiment of the wafer cleaning and drying method of the present disclosure, the cleaning solution 200 is heated deionized water, and the liquid volatile solvent 400 is liquid isopropyl alcohol.

Referring to fig. 3 to 11 again, the present disclosure further discloses a wafer cleaning and drying apparatus 100, which includes a cleaning tank 110, a support 120, and a liquid volatile solvent introduction pipe 130, for performing the wafer cleaning and drying method shown in fig. 1.

The cleaning tank 110 stores a cleaning solution 200 therein, and the cleaning tank 100 has a water inlet 112 disposed at a lower portion, an overflow port 114 disposed at an upper portion, and a water outlet 116 disposed at a bottom portion. The support 120 is disposed in the cleaning tank 110 to vertically support the wafer 300. The liquid volatile solvent introduction pipe 130 is used for introducing the liquid volatile solvent 400 from the periphery of the upper portion of the cleaning tank 110.

Referring to fig. 12 and 13, in the wafer cleaning and drying apparatus 100 of the present disclosure, a drainage plate 118 is further disposed above the cleaning tank 110. After the liquid volatile solvent 400 flows out of the liquid volatile solvent introduction pipe 130, the liquid volatile solvent 400 can be guided to be directly injected into the liquid surface of the cleaning solution 200 through the arrangement of the drainage plate 118. In this way, the use of the flow guiding plate 118 not only can prevent the liquid volatile solvent 400 from being contaminated due to flowing through the overflow port 114 above the cleaning tank 110, but also can reduce the turbidity generated when the liquid volatile solvent 400 is injected into the cleaning solution 200 by the flow guiding plate 118, thereby achieving the effect of shortening the waiting time consumed by the prior art after the liquid volatile solvent is injected to the liquid level of the cleaning solution and then needs to stand still.

As shown in fig. 3 to 11, the wafer cleaning and drying apparatus of the present disclosure further includes an air pumping system 140 disposed at the bottom of the cleaning tank 110 to assist the drying operation of the wafer 200 and shorten the drying time.

In summary, according to the method for injecting liquid volatile solvent in two stages of the method for cleaning and drying a wafer and the flow guiding plate of the apparatus for cleaning and drying a wafer of the present disclosure, when the liquid volatile solvent is injected to the liquid level of the cleaning solution, the waiting time for forming a stable two-phase layer by the liquid volatile solvent and the cleaning solution can be shortened, and the particles or chemicals remaining on the wafer can be removed effectively, so as to complete the cleaning and drying operations of the wafer in the shortest time.

The foregoing is merely a preferred embodiment of the present disclosure, and it should be noted that modifications and refinements may be made by those skilled in the art without departing from the principle of the present disclosure, and these modifications and refinements should also be construed as the protection scope of the present disclosure.