Silicon wafer wet etching device
By designing a silicon wafer wet etching device including the main rotary workbench and the spinning workbench, the spray pipe is used for multi -range spraying, which solves the problem of high cost of traditional alkali throw equipment and cumbersome process. The continuous and smooth operation of the silicon grid etching and cleaning is implemented, reducing the cost of cleaning and improving the accuracy of the etching end monitoring.
Patent Information
- Application Number
- CN202420313369.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-20
- Publication Date
- 2025-01-28
- Estimated Expiration
- 2034-02-20
AI Technical Summary
The existing alkaline polishing equipment needs to add additives to protect the silicon wafer polishing process, resulting in increased costs. The process flow of traditional tank polishing equipment is cumbersome and requires water inlet washing and drying to monitor the etching amount.
A silicon wafer wet etching device is designed, including the main rotary workbench and four self -rotating workbenches. Each of the rotating workbench is configured with weighing sensors. And pickling, the etching and cleaning of the silicon wafer, and the eclipse endpoint through weight detection and monitoring.
This device implements the continuous and smooth operation of the silicon wafer, reduces the demand for positive protection, reduces the cost of cleaning, and more accurately monitors the eclipse endpoint through the weight detection system, reducing the generation of bad products.
Smart Images
Figure CN222421892U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of solar cells, and in particular relates to a silicon wafer wet etching device. Background Art
[0002] The improvement of solar cell efficiency is inseparable from the cell's ability to absorb light. Therefore, the first step in preparing the cell is to make a pyramid structure by texturing, and use the principle of light trapping to increase light absorption. However, the double-sided pyramid structure will cause surface carrier recombination during the subsequent grid line printing and sintering process, resulting in reduced cell efficiency. In order to increase the absorption of sunlight without causing excessive carrier recombination, the front side is often texturized and the back side is polished to reduce the back side surface recombination. After polishing the back side, the absorption of long-wavelength light can be increased, achieving greater light absorption and less carrier recombination, thereby improving the conversion efficiency of solar cells.
[0003] The current alkaline polishing equipment uses a tank polishing device. The silicon wafer is immersed in the solution of the polishing tank. Additives need to be added to protect the front of the silicon wafer. At the same time, additives are used to increase the polishing rate of the back of the silicon wafer, which increases the cost. This link also requires monitoring the etching amount. Traditional tank polishing equipment needs to be washed and dried after polishing, and then the silicon wafer is taken out to weigh and calculate the etching amount. The process is cumbersome. Utility Model Content
[0004] The embodiment of the utility model provides a silicon wafer wet etching device, aiming to reduce the cleaning cost of the silicon wafer.
[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: to provide a silicon wafer wet etching device, comprising:
[0006] Main rotary table;
[0007] Four self-rotating worktables are evenly distributed around the main rotating worktable and are connected to the main rotating worktable through a supporting carrier; each of the self-rotating worktables is equipped with a weighing sensor; and
[0008] Four spray pipes are evenly distributed around the main rotating worktable, and the four self-rotating worktables can correspond one by one to the bottom of the four spray pipes as the main rotating worktable rotates.
[0009] In one achievable manner, the main rotating worktable has a central cavity, and the four spray pipes are bent from the bottom of the main rotating worktable and extend into the central cavity thereof, and extend vertically upward in the central cavity.
[0010] In one practicable manner, the four spray pipes are brought close to each other and locked by a binding buckle.
[0011] In one achievable manner, the spray pipe includes a vertical pipe and a bent pipe connected to the upper end thereof, and the bent pipe includes a radial pipe extending radially along the main rotary worktable and a vertical pipe bent downward.
[0012] In one achievable manner, a sprinkler head is provided at the lower end of the vertical pipe.
[0013] In one achievable manner, the sprinkler head is screwed to the lower end of the vertical pipe.
[0014] In one achievable manner, an electrically controlled valve is provided on the vertical pipe.
[0015] In one practicable manner, the bent pipe is connected to the vertical pipe of the spray pipe via a threaded pipe joint.
[0016] In one achievable manner, an oblique support rod is provided between the support carrier plate and the main rotary table.
[0017] Compared with the prior art, the silicon wafer wet etching device provided by the utility model has the following beneficial effects: during etching, a silicon wafer is placed on each self-rotating workbench with the back of the silicon wafer facing upwards, the weight of the original silicon wafer can be weighed first by the weighing sensor on the self-rotating workbench, the liquid sprayed out of each spray pipe is different, and the spray pipes are respectively pre-cleaning, alkali polishing, post-cleaning and acid cleaning according to the rotation direction of the main rotating workbench, the silicon wafer is sprayed at each station on the self-rotating workbench, and the etching and cleaning of the silicon wafer are realized through the rotation conversion station of the main rotating workbench after a certain time or a certain effect is achieved, and the weight data can be weighed at each station, and the end point of etching can be better monitored by comparison, the operation is simple and convenient, and no protection of front additives is required, thereby saving etching and cleaning costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 A schematic diagram of the top view of the structure of a silicon wafer wet etching device provided in an embodiment of the utility model;
[0019] Figure 2 A schematic diagram of the main structure of a silicon wafer wet etching device provided in an embodiment of the utility model;
[0020] Description of reference numerals:
[0021] 1. Main rotating worktable; 2. Spray pipe; 3. Support carrier; 4. Self-rotating worktable; 5. Silicon wafer; 6. Spray head; 7. Electric control valve; 8. Tie buckle; 9. Oblique support rod. DETAILED DESCRIPTION
[0022] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.
[0023] Please also read Figure 1 and Figure 2 The silicon wafer wet etching device provided by the utility model is now described. The silicon wafer wet etching device comprises a main rotating table 1, four self-rotating tables 4 and four spray pipes 2. The four self-rotating tables 4 are evenly distributed around the main rotating table 1 and are connected to the main rotating table 1 through a supporting carrier 3. Each rotating table 4 is equipped with a weighing sensor (not shown in the figure). The four spray pipes 2 are evenly distributed around the main rotating table 1. The four self-rotating tables 4 can correspond to the bottom of the four spray pipes 2 one by one as the main rotating table 1 rotates.
[0024] Based on the device provided by the utility model, the process of alkali polishing of the silicon wafer 5 is: pre-cleaning, water washing, alkali polishing, water washing, post-cleaning, water washing, acid washing, and then dehydration and drying. The specific etching process is as follows:
[0025] (1) The silicon wafer 5 to be polished is placed on a self-rotating platform with a weight sensor and placed under the first spray pipe. The first spray pipe first sprays a mixture of reagents KOH and H2O2 to perform a pre-cleaning process. After the pre-cleaning, the water washing spray head 6 is directly switched to perform water washing. During this process, the self-rotating worktable 4 keeps rotating.
[0026] (2) After the pre-cleaning is completed, the main rotating table 1 rotates the silicon wafer 5 to the bottom of the second spray pipe, firstly checks the weight of the silicon wafer 5, records the data, and then performs alkaline polishing. The second spray pipe first sprays a high-concentration KOH and H2O2 mixed reagent to polish the surface of the silicon wafer 5, and then switches to the water washing system for water washing. During this process, the rotating table 4 keeps rotating. During the alkaline washing process, the surface state of the silicon wafer 5 is observed, the reaction end time is controlled, and after water washing, the silicon wafer 5 is dehydrated by rotation, and the weight after etching is weighed and the data is recorded.
[0027] (3) After the alkaline cleaning is completed, the main rotating table 1 rotates the silicon wafer 5 to the bottom of the third spray pipe for post-cleaning. The third spray pipe first sprays a mixed reagent of KOH and H2O2 to perform post-cleaning on the surface of the silicon wafer 5, and then switches to the water washing system for water washing. During this process, the rotating table 4 keeps rotating.
[0028] (4) After the post-cleaning is completed, the main rotating table 1 rotates the silicon wafer 5 to the bottom of the fourth spray pipe for pickling. The fourth spray pipe first sprays a mixed reagent of HCl and HF to pickle the surface of the silicon wafer 5, while the fourth spray pipe 2 switches to the water washing system for water washing. During this process, the rotating table 4 keeps rotating.
[0029] The present invention adopts single-sided spin etching, does not need to use the additive of the front protection BSG layer, the operation process is continuous and smooth, and the cleaning cost can be saved. Each self-rotating workbench 4 of the device is equipped with a weighing sensor, and the etching surface of the silicon wafer 5 faces upward, so the changes in the etching morphology can be visually seen by the naked eye, and the end point of the etching can be monitored through the weight detection system connected to the weight sensor, so that the damage to the silicon wafer 5 is smaller, and the generation of defective products such as tooth marks and water marks is reduced.
[0030] Among them, the main rotating worktable 1 and the self-rotating worktable 4 can both adopt a rotational driving method in which a small gear drives a large ring gear, and the large ring gear can be internal teeth or external teeth; when the large ring gear is external teeth, a cylinder is arranged above the large ring gear to facilitate the connection of each supporting carrier plate 3; wherein the supporting carrier plates 3 can be overlapped and fixed on the cylinder by bolts.
[0031] The main rotating worktable 1 drives the four self-rotating worktables 4 to rotate, and the rotation of the self-rotating worktables 4 can drive the silicon wafers 5 thereon to rotate.
[0032] The rotary table is a rotary device commonly used in the mechanical field, and the device can adopt the existing rotary table.
[0033] You can purchase a suitable type of weighing sensor, which can be installed on the side of the self-rotating workbench.
[0034] In some embodiments, see Figure 1 and Figure 2 The main rotating worktable 1 has a central cavity, and the four spray pipes 2 are bent from the bottom of the main rotating worktable 1 and extend into the central cavity thereof, and extend vertically upward in the central cavity.
[0035] See also Figure 2 In some embodiments, the four spray pipes 2 are close to each other and locked by the binding buckle 8 to improve the support strength of the spray pipe 2. The binding buckle 8 can be a binding belt, a clamp, etc.
[0036] See also Figure 2 In some embodiments, the spray pipe 2 includes a vertical pipe and a bent pipe connected to the upper end thereof, and the bent pipe includes a radial pipe extending radially along the main rotary table 1 and a vertical pipe bent downward. The bent pipe allows the spray head 6 to spray downward.
[0037] In some embodiments, see Figure 1 and Figure 2 A spray head 6 is provided at the lower end of the vertical tube to increase the area of the silicon wafer 5 sprayed.
[0038] In some embodiments, see Figure 1 and Figure 2 The sprinkler head 6 is screwed to the lower end of the vertical pipe, which is convenient for disassembly and replacement of the sprinkler head 6.
[0039] In some embodiments, see Figure 2 An electric control valve 7 is provided on the vertical pipe to facilitate the control of the reagent flow rate and shut down.
[0040] In some embodiments, the bent pipe is connected to the vertical pipe of the spray pipe 2 through a threaded pipe joint, which facilitates the installation of the spray pipe 2.
[0041] In some embodiments, see Figure 2 An oblique support rod 9 is arranged between the support carrier plate 3 and the main rotating worktable 1 to support the self-rotating worktable 4.
[0042] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.
[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A silicon wafer wet etching device, characterized in that: include: Main rotary table (1); Four self-rotating worktables (4) are evenly distributed around the main rotating worktable (1) and are connected to the main rotating worktable (1) via a supporting carrier (3); each of the self-rotating worktables (4) is equipped with a weighing sensor; and Four spray pipes (2) are evenly distributed around the main rotating worktable (1), and the four self-rotating worktables (4) can correspond one by one to the bottom of the four spray pipes (2) as the main rotating worktable (1) rotates.
2. The silicon wafer wet etching device according to claim 1, characterized in that: The main rotating worktable (1) has a central cavity, and the four spray pipes (2) are bent from the bottom of the main rotating worktable (1) and extend into the central cavity, and extend vertically upward in the central cavity.
3. The silicon wafer wet etching device according to claim 2, characterized in that: The four spray pipes (2) are close to each other and locked by a fastening buckle (8).
4. The silicon wafer wet etching device according to claim 1, characterized in that: The spray pipe (2) comprises a vertical pipe and a bent pipe connected to the upper end thereof, and the bent pipe comprises a radial pipe extending radially along the main rotary worktable (1) and a vertical pipe bent downward.
5. The silicon wafer wet etching device according to claim 4, characterized in that: A spray head (6) is provided at the lower end of the vertical pipe.
6. The silicon wafer wet etching device according to claim 5, characterized in that: The spray head (6) is screwed to the lower end of the vertical pipe.
7. The silicon wafer wet etching device according to claim 4, characterized in that: An electric control valve (7) is arranged on the vertical pipe.
8. The silicon wafer wet etching device according to claim 4, characterized in that: The bent pipe is connected to the vertical pipe of the spray pipe (2) via a threaded pipe joint.
9. The silicon wafer wet etching device according to claim 1, characterized in that: An oblique support rod (9) is provided between the support carrier plate (3) and the main rotary worktable (1).