TWI866065B - Silicon material processing method and device - Google Patents

Abstract

The present invention provides a silicon material processing method and a device thereof. The silicon material processing method comprises the following steps: providing a standard silicon wafer and silicon material to be processed; placing the standard silicon wafer and the silicon material to be processed into a reaction tank for reaction; detecting the reaction state parameters of the standard silicon wafer; and adjusting the reaction process of the silicon material to be processed according to the reaction state parameters of the standard silicon wafer.

Description

Silicon material processing method and device

This invention claims priority to Chinese Patent Application No. 202211686475.1 filed in China on December 26, 2022, the entire contents of which are incorporated herein by reference.

The present invention relates to the field of semiconductor technology, and more particularly to a silicon material processing method and device.

As the basic material of single-crystal silicon in the semiconductor industry, polycrystalline silicon has extremely high cleanliness requirements. In the semiconductor production process, such as the crystal pulling process, many unqualified crystal rods may appear. In the subsequent rolling and cutting process, occasional machine failures may cause single-crystal silicon to crack. At this time, it is necessary to recycle the polycrystalline part and the cracked silicon materials to reduce the cost of raw materials. However, after the transportation and multiple transfers of the crystal rods, they will be exposed to many pollutants, mainly metal particles on the surface of the polycrystalline silicon raw materials and other organic or inorganic pollutants, which requires them to be thoroughly cleaned for reuse. Since the shape of polysilicon raw materials is usually irregular, it is difficult to effectively determine the progress of the cleaning and recovery reaction process by the surface state of polysilicon, which may affect the quality of the recovered polysilicon raw materials.

The present invention provides a silicon material processing method and device to improve the quality of recycled polycrystalline silicon raw materials.

To solve the above problems, the present invention is implemented as follows:

In the first aspect, the embodiment of the present invention provides a silicon material processing method, comprising the following steps: providing a standard silicon wafer and silicon material to be processed; placing the standard silicon wafer and the silicon material to be processed into a reaction tank for reaction; detecting the reaction state parameters of the standard silicon wafer; and adjusting the reaction process of the silicon material to be processed according to the reaction state parameters of the standard silicon wafer.

In some embodiments, the reaction state parameter includes at least one of the etching thickness of the standard silicon wafer and the surface gloss of the standard silicon wafer.

In some embodiments, the reaction state parameter includes the surface gloss of the standard silicon wafer; the reaction process of the silicon material to be processed is adjusted according to the reaction state parameter of the standard silicon wafer, including: detecting the relationship between the surface gloss of the standard silicon wafer and the preset gloss range when the reaction time is the first preset reaction time; when the surface gloss of the standard silicon wafer is less than the minimum value of the preset gloss range, increasing the concentration of the reaction liquid in the reaction tank; when the surface gloss of the standard silicon wafer is greater than the maximum value of the preset gloss range, reducing the concentration of the reaction liquid in the reaction tank; when the surface gloss of the standard silicon wafer is within the preset gloss range, terminating the current reaction process.

In some embodiments, the reaction state parameter includes the etching thickness of the standard silicon wafer; the reaction process of the silicon material to be processed is adjusted according to the reaction state parameter of the standard silicon wafer, including: detecting the relationship between the etching thickness of the standard silicon wafer and the preset thickness range when the reaction time is the first preset reaction time; when the etching thickness of the standard silicon wafer is less than the minimum value of the preset thickness range, increasing the concentration of the reaction liquid in the reaction tank; when the etching thickness of the standard silicon wafer is greater than the maximum value of the preset thickness range, reducing the concentration of the reaction liquid in the reaction tank; when the etching thickness of the standard silicon wafer is within the preset thickness range, terminating the current reaction process.

In some embodiments, adjusting the reaction process of the silicon material to be processed according to the reaction state parameters of the standard silicon wafer includes: when the surface gloss of the standard silicon wafer is within the preset gloss range, determining the target reaction time corresponding to the reaction process and terminating the current reaction process; when the target reaction time is greater than the maximum value of the second preset reaction time, increasing the concentration of the reaction liquid in the reaction tank; when the target reaction time is less than the minimum value of the second preset reaction time, reducing the concentration of the reaction liquid in the reaction tank.

In some embodiments, adjusting the reaction process of the silicon material to be processed according to the reaction state parameters of the standard silicon wafer includes: when the etching thickness of the standard silicon wafer is within the preset thickness range, determining the target reaction time corresponding to the reaction process and terminating the current reaction process; when the target reaction time is greater than the maximum value of the second preset reaction time, increasing the concentration of the reaction liquid in the reaction tank; when the target reaction time is less than the minimum value of the second preset reaction time, reducing the concentration of the reaction liquid in the reaction tank.

In the second aspect, the embodiment of the present invention provides a silicon material processing device for implementing any of the silicon material processing methods described above, wherein the silicon material processing device comprises a reaction tank and a fixing assembly, wherein the fixing assembly is used to move the silicon material to be processed and the standard silicon wafer into or out of the reaction tank.

In some embodiments, the reaction tank includes a process tank and a wafer dispensing tank that are interconnected, the process tank is used to accommodate silicon materials to be processed, and the wafer dispensing tank is used to accommodate standard silicon wafers.

In some embodiments, there are multiple process tanks, and the multiple process tanks are arranged in sequence, and the multiple process tanks correspond to different reaction processes respectively; the fixed assembly includes a rail and a robot arm, the rail extends along the arrangement direction of the multiple process tanks, the robot arm is slidably arranged on the rail, and the robot arm is used to drive the silicon material to be processed and the standard silicon wafer to move to the corresponding reaction tank.

In some embodiments, a material basket and a silicon wafer clamp are provided on the robot arm, the material basket is used to contain the silicon material to be processed, and the silicon wafer clamp is used to fix the standard silicon wafer.

The embodiment of the present invention can improve the accuracy of controlling the reaction process of the silicon material and improve the control effect by controlling the reaction process of the silicon material according to the reaction state parameters of the standard silicon wafer.

1: Process tank

2: Film slot

11: Wetting tank

12: Etching grooves

13: Cleaning tank

4: Basket

5: Silicon materials to be processed

6: Support frame

7: Standard silicon wafer

8: Robotic arm

9:Guide rails

201~204: Steps

In order to more clearly explain the technical solution of the embodiment of the present invention, the following will briefly introduce the drawings required for use in the description of the embodiment of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those with ordinary knowledge in the technical field to which the present invention belongs, other drawings can be obtained based on these drawings without paying progressive labor.

FIG. 1A is a structural diagram of a silicon material processing device provided by an embodiment of the present invention; FIG. 1B is another structural diagram of a silicon material processing device provided by an embodiment of the present invention; and FIG. 2 is a flow chart of a silicon material processing method provided by an embodiment of the present invention.

The following will combine the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons with ordinary knowledge in the technical field to which the present invention belongs without making progressive efforts are within the scope of protection of the present invention.

The terms "first", "second", etc. in the embodiments of the present invention are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices. In addition, the use of "and/or" in the present invention represents at least one of the connected objects, such as A and/or B and/or C, which means that it includes 7 situations including A alone, B alone, C alone, and both A and B exist, both B and C exist, both A and C exist, and A, B and C exist.

An embodiment of the present invention provides a silicon material processing device.

As shown in FIG. 1A and FIG. 1B , in one embodiment, the silicon material processing device includes a reaction tank and a fixing assembly, and the fixing assembly is used to move the silicon material 5 to be processed and the standard silicon wafer 7 into or out of the reaction tank. Here, the reaction tank can be used for etching, cleaning and other processes of the silicon material.

In some embodiments, the reaction tank includes a process tank 1 and a wafer dispensing tank 2 that are interconnected, each wafer dispensing tank 2 is connected to the corresponding process tank 1, different process tanks 1 are independent of each other, and different wafer dispensing tanks 2 are also independent of each other, thereby ensuring the consistency of the liquid components in the process tank 1 and the corresponding wafer dispensing tank 2. The process tank 1 is used to accommodate the silicon material 5 to be processed, and the wafer dispensing tank 2 is used to accommodate the standard silicon wafer 7. In one embodiment, the wafer dispensing tank 2 is set on the side of the reaction tank, and the side wall of the wafer dispensing tank 2 is a transparent material, so that the state of the standard silicon wafer 7 can be easily observed.

Please continue to refer to Figure 1. In some embodiments, there are multiple process tanks 1, and the multiple process tanks 1 are arranged in sequence. The multiple process tanks 1 correspond to different reaction processes. For example, they can correspond to the steps of soaking, etching, and cleaning after etching in sequence. Correspondingly, in this embodiment, a soaking tank 11, an etching tank 12, and a cleaning tank 13 are provided, totaling three reaction tanks.

The fixed assembly includes a guide rail 9, a support frame 6 and a robot arm 8. The guide rail 9 extends along the arrangement direction of the multiple process tanks 1. The robot arm 8 can be slidably arranged on the guide rail 9. The robot arm 8 is used to drive the silicon material 5 to be processed and the standard silicon wafer 7 to move to the corresponding reaction tank. Specifically, the robot arm 8 is provided with a support frame 6, and the support frame 6 is fixed with a material basket 4 and a silicon wafer clamp. The material basket 4 is used to accommodate the silicon material 5 to be processed, and the silicon wafer clamp is used to fix the standard silicon wafer 7. In this way, the silicon material 5 to be processed and the standard silicon wafer 7 can be driven by the fixed assembly to move to each reaction tank in turn to perform the corresponding process steps.

It can be understood that the silicon material processing device of this embodiment can be applied to the silicon material processing method in the embodiment of the present invention, but the silicon material processing method does not necessarily rely on the silicon material processing device for implementation. During implementation, the structure of the silicon material processing device can be adaptively adjusted.

As shown in FIG2 , an embodiment of the present invention provides a silicon material processing method.

Includes the following steps:

Step 201: Provide standard silicon wafers and silicon materials to be processed.

In this embodiment, the standard silicon wafer is a silicon wafer made according to certain standards, for example, it can be a silicon wafer with a certain surface glossiness, or it can be a silicon wafer with a certain thickness. In some embodiments, the size and other parameters of the silicon wafer can also be restricted. The silicon material to be processed refers to the silicon material that needs to be recycled.

Step 202: Place the standard silicon wafer and the silicon material to be processed into a reaction tank for reaction.

Next, the standard silicon wafer and the silicon material to be processed are placed in a reaction tank for reaction. In this embodiment, since the environment in the reaction tank is the same, the reaction conditions of the standard silicon wafer and the silicon material to be processed are the same.

Taking the process steps of etching the silicon material to be processed as an example, at this time, the reaction liquid in the reaction tank is a mixed solution of nitric acid and hydrofluoric acid. When the standard silicon wafer and the silicon material to be processed are placed in the reaction tank, the standard silicon wafer and the silicon material to be processed can be etched at the same time under the same conditions.

Step 203: Detect the reaction state parameters of the standard silicon wafer.

Next, the reaction state parameters of the standard silicon wafer are detected. In some embodiments, the reaction state parameters include at least one of the etching thickness of the standard silicon wafer and the surface gloss of the standard silicon wafer. In this embodiment, the reaction state parameters of the silicon wafer to be tested can be detected by visual observation by staff or by using a pattern sensor.

It should be understood that as the etching process proceeds, the thickness of the standard silicon wafer will gradually decrease, and at the same time, its surface damage layer will also be gradually etched away, that is, the surface gloss of the standard silicon wafer will gradually increase. Therefore, in this embodiment, the progress of the etching process can be determined by the etching thickness and surface gloss of the standard silicon wafer.

Step 204: Adjust the reaction process (reaction flow, reaction process) of the silicon material to be processed according to the reaction state parameters of the standard silicon wafer.

The progress of the reaction can be determined by the reaction state parameters of the standard silicon wafer. Accordingly, the reaction process can be adjusted according to the reaction state parameters of the standard silicon wafer to ensure that the silicon material to be processed reaches the required reaction state, which can not only ensure the quality of the recycled silicon material, but also avoid wasting the reaction liquid. In this way, the embodiment of the present invention can improve the accuracy of the control of the reaction process of the silicon material and improve the control effect by controlling the reaction process of the silicon material according to the reaction state parameters of the standard silicon wafer.

In some embodiments, the reaction state parameter includes the surface gloss of the standard silicon wafer, and step 204 includes: detecting the relationship between the surface gloss of the standard silicon wafer and the preset gloss range when the reaction time is the first preset reaction time; increasing the concentration of the reaction liquid in the reaction tank when the surface gloss of the standard silicon wafer is less than the minimum value of the preset gloss range; reducing the concentration of the reaction liquid in the reaction tank when the surface gloss of the standard silicon wafer is greater than the maximum value of the preset gloss range; terminating the current reaction process when the surface gloss of the standard silicon wafer is within the preset gloss range.

In one embodiment, the state of the reaction liquid can be determined according to the state of the standard silicon wafer, and the reaction liquid can be adjusted in time.

Specifically, in this embodiment, the reaction time is set to a first preset time, and when the reaction reaches the first preset time, the surface gloss of the standard silicon wafer is detected.

It should be understood that for a known standard silicon wafer, its initial surface gloss is known. After knowing the current surface gloss, the change in the surface gloss of the standard silicon wafer can be determined, thereby determining the reaction process. In practice, the corresponding relationship between the change in the surface gloss of the standard silicon wafer and the reaction process can be determined by conducting tests in advance. In this way, after knowing the current surface gloss of the standard silicon wafer, the reaction process can be determined.

For example, a preset gloss range can be set. If the current surface gloss of the standard silicon wafer is within the range, it means that the etching process is within the desired range. At this time, the reaction process is terminated to obtain the silicon material to be processed that meets the requirements.

It is understandable that if the surface gloss of the standard silicon wafer is greater than the maximum value of the preset gloss range, it means that the standard silicon wafer has been over-etched. At this time, the concentration of the etching solution can be appropriately reduced. At the same time, the reaction process is terminated and the next etching is carried out to ensure that the reaction process of the silicon material to be treated in the subsequent steps is within a reasonable range.

If the surface gloss of the standard silicon wafer is less than the minimum value of the preset gloss range, it means that the standard silicon wafer is not etched enough. At this time, the concentration of the etching solution can be appropriately increased. At the same time, the silicon wafer to be processed can be further etched and the surface gloss of the standard silicon wafer can be tested again after a certain period of time until the surface gloss of the standard silicon wafer is within the preset gloss range to ensure that the obtained silicon material meets the requirements.

In some embodiments, the reaction state parameter includes the etching thickness of the standard silicon wafer; the reaction process of the silicon material to be processed is adjusted according to the reaction state parameter of the standard silicon wafer, including: detecting the relationship between the etching thickness of the standard silicon wafer and the preset thickness range when the reaction time is the first preset reaction time; when the etching thickness of the standard silicon wafer is less than the minimum value of the preset thickness range, increasing the concentration of the reaction liquid in the reaction tank; when the etching thickness of the standard silicon wafer is greater than the maximum value of the preset thickness range, reducing the concentration of the reaction liquid in the reaction tank; when the etching thickness of the standard silicon wafer is within the preset thickness range, terminating the current reaction process.

Similar to the above process, in this embodiment, the reaction state of the silicon material to be processed is determined according to the etching thickness of the standard silicon wafer. Obviously, if the etching thickness of the standard silicon wafer is greater than the maximum value of the preset thickness range, it means that over-etching has been performed. If the etching thickness of the standard silicon wafer is less than the minimum value of the preset thickness range, it means that the etching is insufficient. If the etching thickness of the standard silicon wafer is within the preset thickness range, it is considered that the etching process is within a reasonable range. Accordingly, the concentration of the reaction liquid or the progress of the reaction process can be adjusted.

h

H2，其表面光澤度g滿足G1

g

G2，則認為反應進程處於正常狀態，此時，結束反應，如果上述兩個條件中的任一者不滿足，則適應性調整反應液濃度。這樣，通過同時限定蝕刻厚度和表面光澤度，能夠提高對於反應進程的控制精度。 In some embodiments, the etching state can also be determined based on the etching thickness and the surface glossiness. For example, the preset thickness range can be set to H1 to H2, and the preset glossiness range can be set to G1 to G2. In practice, when the thickness h of the standard silicon wafer meets H1

h

H2, whose surface gloss meets G1

g

G2, the reaction process is considered to be in a normal state. At this time, the reaction is terminated. If any of the above two conditions is not met, the concentration of the reaction liquid is adaptively adjusted. In this way, by simultaneously limiting the etching thickness and surface gloss, the control accuracy of the reaction process can be improved.

In some other embodiments, the above ranges can be appropriately adjusted. For example, H1=6.5 microns, 6.7 microns, 6.8 microns, 7.1 microns, etc.; H2=7.6 microns, 7.7 microns, 7.9 microns, 8 microns, etc.; G1=68 gloss unit (GU), 69 GU, 71 GU, 72 GU, etc.; G2=74 GU, 76 GU, 77 GU, 80 GU, etc.

In an exemplary embodiment, H1=7 microns, H2=7.8 microns, G1=70 GU, G2=75 GU, and controlling the preset thickness range and the preset gloss range within the above range can effectively improve the control accuracy of the reaction process, that is, ensure the processing effect of the silicon material, and avoid wasting the reaction solution.

In this way, the technical solution of this embodiment can effectively reduce the metal content on the surface of the silicon material and improve the quality of the silicon material.

In some other embodiments, the reaction time can also be adjusted according to the reaction state parameters.

In some embodiments, adjusting the reaction process of the silicon material to be processed according to the reaction state parameters of the standard silicon wafer includes: when the surface gloss of the standard silicon wafer is within the preset gloss range, determining the target reaction time corresponding to the reaction process and terminating the current reaction process; when the target reaction time is greater than the maximum value of the second preset reaction time, increasing the concentration of the reaction liquid in the reaction tank; when the target reaction time is less than the minimum value of the second preset reaction time, reducing the concentration of the reaction liquid in the reaction tank.

It should be understood that in this embodiment, when the surface gloss of the standard silicon wafer is within the preset gloss range, if the corresponding target reaction time is too long, it means that the etching speed is slow. At this time, the concentration of the reaction liquid needs to be appropriately increased. If the target reaction time is too short, it means that the etching speed is too fast. At this time, the concentration of the reaction liquid needs to be reduced to reduce the etching speed.

In some embodiments, adjusting the reaction process of the silicon material to be processed according to the reaction state parameters of the standard silicon wafer includes: when the etching thickness of the standard silicon wafer is within the preset thickness range, determining the target reaction time corresponding to the reaction process and terminating the current reaction process; when the target reaction time is greater than the maximum value of the second preset reaction time, increasing the concentration of the reaction liquid in the reaction tank; when the target reaction time is less than the minimum value of the second preset reaction time, reducing the concentration of the reaction liquid in the reaction tank.

Similar to the above process, in this embodiment, the etching speed is determined according to the etching thickness, and the concentration of the reaction liquid is adjusted accordingly.

In some other embodiments, the concentration of the reaction liquid can also be adjusted according to the etching thickness and surface glossiness at the same time. The principle can be referred to in the above embodiments and will not be elaborated here.

The above is the preferred implementation of the embodiment of the present invention. It should be pointed out that for those with ordinary knowledge in the technical field of the present invention, various improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

201~204: Steps

Claims (8)

A silicon material processing method comprises the following steps: providing a standard silicon wafer and a silicon material to be processed; placing the standard silicon wafer and the silicon material to be processed in a reaction tank for reaction; detecting the state parameters of the standard silicon wafer; and adjusting the reaction process of the silicon material to be processed according to the reaction state parameters of the standard silicon wafer; wherein the reaction state parameters include the surface gloss of the standard silicon wafer; wherein adjusting the reaction process of the silicon material to be processed according to the reaction state parameters of the standard silicon wafer comprises: detecting the reaction time; When the first preset reaction time is reached, the relationship between the surface gloss of the standard silicon wafer and the preset gloss range; when the surface gloss of the standard silicon wafer is less than the minimum value of the preset gloss range, the concentration of the reaction liquid in the reaction tank is increased; when the surface gloss of the standard silicon wafer is greater than the maximum value of the preset gloss range, the concentration of the reaction liquid in the reaction tank is reduced; when the surface gloss of the standard silicon wafer is within the preset gloss range, the current reaction process is terminated. The silicon material processing method as described in claim 1, wherein the reaction state parameter also includes the etching thickness of the standard silicon wafer. The silicon material processing method as described in claim 2, wherein the reaction state parameter includes the etching thickness of the standard silicon wafer; the reaction process of the silicon material to be processed is adjusted according to the reaction state parameter of the standard silicon wafer, including: detecting the relationship between the etching thickness of the standard silicon wafer and the preset thickness range when the reaction time is the first preset reaction time; when the etching thickness of the standard silicon wafer is less than the minimum value of the preset thickness range, increasing the concentration of the reaction liquid in the reaction tank; when the etching thickness of the standard silicon wafer is greater than the maximum value of the preset thickness range, reducing the concentration of the reaction liquid in the reaction tank; when the etching thickness of the standard silicon wafer is within the preset thickness range, terminating the current reaction process. The silicon material processing method as described in claim 1, wherein the reaction process of the silicon material to be processed is adjusted according to the reaction state parameters of the standard silicon wafer, including: when the surface gloss of the standard silicon wafer is within the preset gloss range, determining the target reaction time corresponding to the reaction process and terminating the current reaction process; when the target reaction time is greater than the maximum value of the second preset reaction time, increasing the concentration of the reaction liquid in the reaction tank; when the target reaction time is less than the minimum value of the second preset reaction time, reducing the concentration of the reaction liquid in the reaction tank. The silicon material processing method as described in claim 2 or claim 4, wherein the reaction process of the silicon material to be processed is adjusted according to the reaction state parameters of the standard silicon wafer, including: when the etching thickness of the standard silicon wafer is within the preset thickness range, determining the target reaction time corresponding to the reaction process and terminating the current reaction process; when the target reaction time is greater than the maximum value of the second preset reaction time, increasing the concentration of the reaction liquid in the reaction tank; when the target reaction time is less than the minimum value of the second preset reaction time, reducing the concentration of the reaction liquid in the reaction tank. A silicon material processing device, which is used to implement the silicon material processing method described in any one of claim 1 to claim 5, the silicon material processing device includes a reaction tank and a fixing assembly, the fixing assembly is used to move the silicon material to be processed and the standard silicon wafer into or out of the reaction tank; Wherein, the reaction tank includes a process tank and a wafer dispensing tank that are interconnected, the process tank is used to accommodate the silicon material to be processed, and the wafer dispensing tank is used to accommodate the standard silicon wafer. The silicon material processing device as described in claim 6, wherein the number of the process slots is multiple, and the multiple process slots are arranged in sequence, and the multiple process slots correspond to different reaction processes respectively; the fixed assembly includes a guide rail and a robot arm, the guide rail extends along the arrangement direction of the multiple process slots, the robot arm is slidably arranged on the guide rail, and the robot arm is used to drive the silicon material to be processed and the standard silicon wafer to move to the corresponding reaction slot. The silicon material processing device as described in claim 7, wherein the robot arm is provided with a material basket and a silicon wafer clamp, the material basket is used to accommodate the silicon material to be processed, and the silicon wafer clamp is used to fix the standard silicon wafer.