A carrier for silicon wafer coating and method of using the same

Abstract

The application provides a carrier for silicon wafer coating and a use method thereof. The application is characterized in that an opening is arranged on the side wall of the groove, so that the edge space of the silicon wafer is connected with the normal pressure space outside the carrier, and the edge space of the silicon wafer is kept at normal pressure during the coating process, thereby avoiding that the solution coated on the surface of the silicon wafer is sucked into the vacuum adsorption platform and the bottom of the silicon wafer, and improving the coating uniformity. The distance between the side wall of the groove and the edge of the silicon wafer is adjusted to 0.01mm to 2mm, so that when the knife head of the slit coating device reaches the gap between the groove and the silicon wafer, the solution will not fall into the gap due to the surface tension of the solution, and the upper surface of the silicon wafer is fully covered. The distance between the edge of the silicon wafer and the edge of the vacuum adsorption platform is adjusted to greater than 0 to 30mm, so that the edge of the silicon wafer forms a normal pressure cavity, and at the same time, the edge of the silicon wafer is prevented from sagging or warping, and the coating uniformity and product qualification rate are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the coating technical field, in particular to a carrier for silicon wafer coating and a method thereof. BACKGROUND

[0002] Slit coating is a kind of coating technology that the coating liquid is pressed out along the gap of the mold and transferred to the moving substrate under a certain pressure. It represents the future development direction of wet coating with the characteristics of fast coating speed, good coating uniformity and wide coating window. When high-precision coating is carried out, vacuum adsorption is necessary to ensure flatness because the silicon wafer will deform. However, when precise coating is carried out on the surface of the silicon wafer, the gap between the vacuum adsorption platform below and the silicon wafer will form a strong capillary force. When full coating is carried out, the solution is sucked into the vacuum platform and the bottom of the silicon wafer by the capillary force, resulting in the failure of full coating. Therefore, how to improve the coverage area and uniformity of silicon wafer coating is a problem to be solved in the existing silicon wafer coating process. SUMMARY

[0003] The purpose of the present application is to provide a carrier for silicon wafer coating and a method thereof to improve the coverage area and uniformity of silicon wafer coating. The specific technical solutions are as follows:

[0004] The first aspect of the present application provides a carrier for silicon wafer coating, wherein the carrier comprises a groove and a vacuum adsorption platform,

[0005] The groove has a side wall and a bottom wall, and the side wall has an opening;

[0006] The vacuum adsorption platform is located in the groove, and the height of the vacuum adsorption platform is 10-50mm;

[0007] The silicon wafer is placed on the vacuum adsorption platform in the groove, the position of the opening is lower than the lower surface of the silicon wafer, and the opening makes the silicon wafer and the groove inside and outside be in normal pressure state;

[0008] The distance between the edge of the silicon wafer and the side wall of the groove is 0.01-2mm,

[0009] The distance between the edge of the silicon wafer and the edge of the vacuum adsorption platform is greater than 0-30mm.

[0010] The second aspect of the present application provides a method for using the carrier of the first aspect of the present application, wherein the method comprises:

[0011] Preparation of coating solution;

[0012] Adsorption of the silicon wafer treated by texturing by the vacuum adsorption platform;

[0013] The coating solution is applied to the surface of the silicon wafer by a knife head of a slot coating device from the side wall of the groove and dried to form a coating layer.

[0014] The present application provides a carrier for silicon wafer coating and a method thereof. The present application sets an opening in the side wall of the groove, so that the edge space of the silicon wafer is connected to the normal pressure space outside the carrier, and the edge space of the silicon wafer maintains normal pressure during the coating process, avoiding the solution coated on the surface of the silicon wafer being sucked into the vacuum adsorption platform and the bottom of the silicon wafer, and improving the coating uniformity. By adjusting the distance between the side wall of the groove and the edge of the silicon wafer to 0.01mm to 2mm, when the knife head of the slot coating device reaches the gap between the groove and the silicon wafer, the solution will not fall into the gap due to its own surface tension, thereby fully covering the upper surface of the silicon wafer. By adjusting the distance between the edge of the silicon wafer and the edge of the vacuum adsorption platform to more than 0 to 30mm, the edge of the silicon wafer forms a normal pressure cavity, while avoiding the edge of the silicon wafer from sagging or warping, improving the coating uniformity and product qualification rate.

[0015] Of course, implementing any product or method of the present application does not necessarily require all the advantages described above. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other embodiments can also be obtained by those skilled in the art based on these drawings.

[0017] Figure 1 The figure is a structural schematic diagram of the carrier of the present application. In the figure, 1 is a groove, 1a is a side wall, 1b is a bottom wall, 2 is a vacuum adsorption platform, and 3 is a silicon wafer. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments obtained by those skilled in the art based on the present application are within the scope of protection of the present application.

[0019] The first aspect of the present application provides a carrier for silicon wafer coating, wherein the carrier comprises a groove and a vacuum adsorption platform,

[0020] The groove has a side wall and a bottom wall, and the side wall has an opening;

[0021] The vacuum adsorption platform is located in the groove, and the height of the vacuum adsorption platform is 10mm to 50mm;

[0022] The silicon wafer is placed on a vacuum adsorption platform within the groove, and the opening is positioned below the lower surface of the silicon wafer, so that the silicon wafer and the inside and outside of the groove are under normal pressure.

[0023] The distance between the edge of the silicon wafer and the sidewall of the groove is 0.01 mm to 2 mm.

[0024] The distance between the edge of the silicon wafer and the edge of the vacuum adsorption platform is greater than 0 to 30 mm.

[0025] In some embodiments of the first aspect of this application, such as Figure 1 As shown, the carrier includes: a groove 1 and a vacuum adsorption platform 2.

[0026] The groove 1 has a side wall 1a and a bottom wall 1b, and the side wall 1a has an opening;

[0027] The vacuum adsorption platform 2 is located in the groove 1, and the height of the vacuum adsorption platform 2 is 10mm to 50mm.

[0028] The silicon wafer 3 is placed on the vacuum adsorption platform 2 inside the groove 1. The opening is lower than the lower surface of the silicon wafer 3, and the opening makes the silicon wafer 3 and the inside and outside of the groove 1 under normal pressure.

[0029] The distance between the edge of silicon wafer 3 and the sidewall 1a of groove 1 is 0.01 mm to 2 mm.

[0030] The distance between the edge of silicon wafer 3 and the edge of vacuum adsorption platform 2 is greater than 0 to 30 mm.

[0031] This application establishes openings on the sidewalls of the grooves, positioned below the lower surface of the silicon wafer. This allows the edge space of the silicon wafer to connect to an atmospheric pressure space outside the carrier, maintaining atmospheric pressure at the wafer edge during coating. This prevents the coating solution on the wafer surface from being sucked into the vacuum adsorption platform and the bottom of the wafer, improving coating uniformity. By adjusting the distance between the sidewall of the groove and the edge of the silicon wafer to 0.01 mm to 2 mm, when the cutter head of the slit coating device reaches the gap between the groove and the wafer, the solution will not fall into the gap due to its own surface tension, thus achieving full coverage of the upper surface of the silicon wafer. By adjusting the distance of the silicon wafer edge beyond the edge of the vacuum adsorption platform to greater than 0 to 30 mm, an atmospheric pressure cavity is formed at the wafer edge. This avoids excessive distance causing the wafer edge to sag or warp, thereby improving coating uniformity and product yield. In this application, atmospheric pressure refers to one atmosphere.

[0032] This application does not have any particular limitation on the material of the groove, as long as it can achieve the purpose of this application; for example, the material of the groove is selected from stainless steel, aluminum plate, and glass.

[0033] In the present application, the opening in the side wall is a through opening inside and outside the groove, and the height of the opening is not particularly limited as long as the purpose of the present application can be achieved; preferably, the height of the opening is 0.5-2 mm.

[0034] Preferably, the distance between the edge of the silicon wafer and the side wall of the groove is 0.5-1 mm.

[0035] Preferably, the distance between the edge of the silicon wafer and the edge of the vacuum adsorption platform is 0.3-25 mm, more preferably, the distance between the edge of the silicon wafer and the edge of the vacuum adsorption platform is 0.3-15 mm.

[0036] The shape of the groove is not particularly limited in the present application as long as the purpose of the present application can be achieved; in some embodiments of the first aspect of the present application, the shape of the groove is selected from a circle, a rectangle, a square or a corner square.

[0037] In some embodiments of the first aspect of the present application, the vacuum adsorption platform is provided with a small hole, the diameter of the small hole is 0.05-2 mm, and the small hole area density of the vacuum adsorption platform is 10-300 / cm 2 . 2 .

[0038] In some embodiments of the first aspect of the present application, the flatness of the vacuum adsorption platform is less than 20 μm, and the adsorption force of the vacuum adsorption platform is 0.1-50 N. By adjusting the flatness of the vacuum adsorption platform to be less than 20 μm, the present application is beneficial to improve the flatness of the coating layer and improve the coating precision; by adjusting the adsorption force of the vacuum adsorption platform within the above range, it is beneficial to improve the bonding strength between the vacuum adsorption platform and the silicon wafer, so that the silicon wafer will not easily fall off.

[0039] The second aspect of the present application provides a use method of the carrier of the first aspect of the present application, wherein the method comprises:

[0040] Preparation of a coating solution;

[0041] Adsorption of the silicon wafer after texturing treatment by the vacuum adsorption platform;

[0042] From the side wall of the groove, the coating solution is coated on the surface of the silicon wafer by the knife head of the slot coating device and dried to prepare a coating layer.

[0043] The use of the carrier of the present application for slot coating makes the surface of the silicon wafer be completely coated, and the coating uniformity is good, the coating layer uniformity is high, and the coating precision is greatly improved.

[0044] The coating solution is not particularly limited in the present application, and can be any coating solution that can be slit-coated using the carrier of the present application; for example, the coating solution can be a coating solution for an electronic device, such as one or more of a hole transport layer precursor solution, a perovskite layer precursor solution, and an electron transport layer precursor solution in a perovskite battery.

[0045] In the present application, the texturing is a conventional process, which is not particularly limited in the present application, as long as the purpose of the present application can be achieved; in some embodiments of the second aspect of the present application, the texturing process comprises placing a silicon wafer in an alkaline solution for etching to obtain a silicon wafer with a pyramid morphology on the surface with a vertical height of 500 nm to 5 μm; the alkaline solution is an inorganic alkaline solution and / or an organic alkaline solution; the inorganic alkaline solution can be selected from at least one of KOH solution, NaOH solution, Na2SiO3, and Na3PO4 solution, and the organic alkaline solution can be selected from at least one of EPW (ethylenediamine, phthalic acid, and water) and tetramethylammonium hydroxide (TMAH); the concentration of the alkaline solution is 2-20 wt% or 2-20 vol%.

[0046] In the present application, the knife head of the slit coating device starts coating from the side wall of the groove, and at the junction of the side wall and the edge of the silicon wafer, direct knife jump coating is performed by using the liquid surface tension. By adjusting the distance between the side wall of the groove and the edge of the silicon wafer to 0.01 mm to 2 mm, when the knife head of the slit coating device reaches the gap between the groove and the silicon wafer, the solution will not fall into the gap due to its own surface tension, thereby achieving full coating of the surface of the silicon wafer.

[0047] In some embodiments of the second aspect of the present application, the suction pressure of the slit coating device is -1 kPa to -500 kPa, the coating liquid filling time is 0.01 s to 99 s, the coating speed is 0.1 mm / s to 300 mm / s, the coating width is 0.5 cm to 37 cm, and the coating thickness is 0.1 μm to 3000 μm; preferably, the coating liquid filling time is 0.1 s to 20 s, the coating speed is 1 mm / s to 200 mm / s, the coating width is 5 cm to 35 cm, and the coating thickness is 0.1 μm to 10 μm.

[0048] In some embodiments of the second aspect of the present application, the distance between the knife head of the slit coating device and the silicon wafer is 0.1 μm to 3000 μm; preferably, the distance between the knife head of the slit coating device and the silicon wafer is 5 μm to 500 μm.

[0049] In the present application, the conditions for drying are not particularly limited, as long as the purpose of the present application can be achieved; in some embodiments of the second aspect of the present application, the drying temperature is 60°C to 120°C, and the time is 5 min to 20 min.

[0050] Embodiment

[0051] Hereinafter, examples and comparative examples are given to explain the embodiments of the present application more specifically, and it should be noted that the following contents of the present application are explained by taking the example of using a perovskite precursor material as a coating solution to prepare a perovskite coating layer, but the coating solution of the present application is not limited to the perovskite precursor material. Various tests and evaluations are carried out according to the following methods.

[0052] Test methods and equipment:

[0053] Flatness test of vacuum adsorption platform:

[0054] The flatness of the vacuum adsorption platform is measured by using a high-precision micrometer (model 543-390, Sankyo) or a line laser (model LJ-8900, Keyence).

[0055] Uniformity test of coating layer:

[0056] The average values a1 and a2 of the thickness before and after each two points are measured by using a step meter (model DEKTAK XT, Bruker) with multiple point sampling (not less than 16 points), and the uniformity is calculated as 100% x {(a1-a2) ÷ [(a1+a2) / 2]} and the average value is obtained.

[0057] Preparation of coating solution: 44 mL of hydroiodic acid (48 wt%) is added to 27.8 mL of methylamine aqueous solution (40 wt%), and stirred in an ice bath at 0°C for 2 h; the above product is evaporated at 50°C for 1 h, the obtained precipitate is dissolved in anhydrous ethanol and recrystallized in diethyl ether, and finally dried at 60°C under vacuum for 24 h to obtain CH3NH3I; CH3NH3I and PbI2 are added to dimethylformamide in a molar ratio of 1:1, and reacted at 60°C for 12 h to obtain a 1.0 mol / L CH3NH3PbI3 coating solution.

[0058] Example 1

[0059] A stainless steel SUS304 groove is taken, which has a side wall and a bottom wall, and the side wall is provided with an opening with a height of 1 mm;

[0060] The vacuum adsorption platform (self-developed) is located in the groove, the height of the vacuum adsorption platform is 20 mm, the flatness is 3 μm, the adsorption force is 10 N, and the vacuum adsorption platform is provided with small holes with a diameter of 0.3 mm and a small hole area density of 200 / cm 2 ;

[0061] The silicon wafer is placed on the vacuum adsorption platform in the groove, and the position of the side wall opening is lower than the lower surface of the silicon wafer.

[0062] The distance between the edge of the silicon wafer and the side wall of the groove is regulated to be 0.5 mm, and the distance between the edge of the silicon wafer and the edge of the vacuum adsorption platform is regulated to be 2 mm.

[0063] The silicon wafer is a silicon wafer after texturing treatment, specifically: the silicon wafer is placed in a 5wt% KOH solution for etching to obtain a silicon wafer with a pyramid pattern on the surface with a vertical height of 500 nm.

[0064] The silicon wafer after texturing treatment is adsorbed by the vacuum adsorption platform.

[0065] The coating solution is coated on the surface of the silicon wafer by the knife head of the slot coating device from the side wall of the groove and dried to obtain a coating layer, wherein the adsorption pressure of the slot coating device is -100 kPa, the coating liquid filling time is 1.6 s, the coating speed is 20 mm / s, the coating width is 10 cm, the coating thickness is 5 μm, the distance between the knife head of the slot coating device and the silicon wafer is 30 μm, the drying temperature is 100°C, and the drying time is 10 min.

[0066] Example 2-17

[0067] Except that the parameters of the related carrier and the parameters of the slot coating device are changed as shown in Table 1, the rest is the same as Example 1.

[0068] Comparative Example 1

[0069] Except that the side wall of the groove is not provided with an opening, the rest is the same as Example 1.

[0070] Comparative Example 2-3

[0071] Except that the parameters of the related carrier are changed as shown in Table 1, the rest is the same as Example 1.

[0072]

[0073]

[0074] As shown in Table 1, according to the results of Examples 1-17 and Comparative Examples 1-2 and the observed coating conditions, when the side wall is not provided with an opening or the distance between the edge of the silicon wafer and the edge of the vacuum adsorption platform is less than 0, it is difficult to form an atmospheric space between the groove, the vacuum adsorption platform and the silicon wafer, and at the same time, due to the pyramidal shape of the bottom of the silicon wafer, a strong capillary force is formed between the vacuum adsorption platform and the silicon wafer. When full coating is implemented, the coating solution is sucked into the vacuum adsorption platform and the bottom of the silicon wafer under the action of the capillary force, so that the coating solution adheres to the edge and the bottom of the silicon wafer, resulting in failure of full coating and poor uniformity of the coating layer. According to the results of Example 1 and Comparative Example 3 and the observed coating conditions, when the distance between the edge of the silicon wafer and the edge of the vacuum adsorption platform is greater than 30 mm, such as 35 mm, the edge of the silicon wafer will sag and warp, so that the surface of the silicon wafer cannot be fully covered, and the uniformity of the coating layer is poor, resulting in a significant decrease in product pass rate.

[0075] According to the results of Examples 1-17, the use of the carrier provided in the present application for slit coating can ensure full coverage of the surface of the silicon wafer, significantly improve the uniformity of the coating layer, greatly improve the coating precision, and thus improve the product pass rate.

[0076] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A carrier for silicon wafer coating, wherein, The carrier comprises a groove and a vacuum adsorption platform, The groove has a side wall and a bottom wall, and the side wall has an opening; The vacuum adsorption platform is located in the groove, and the height of the vacuum adsorption platform is 10-50 mm; The silicon wafer is placed on the vacuum adsorption platform in the groove, the position of the opening is lower than the lower surface of the silicon wafer, and the opening makes the silicon wafer and the inside and outside of the groove in normal pressure state; The distance between the edge of the silicon wafer and the side wall of the groove is 0.01-2 mm, The distance between the edge of the silicon wafer and the edge of the vacuum adsorption platform is 0.3-25 mm.

2. The vehicle of claim 1, wherein, The distance between the edge of the silicon wafer and the side wall of the groove is 0.5-1 mm.

3. The vehicle of claim 1, wherein, The shape of the groove is selected from circle, rectangle, square or corner square.

4. The vehicle of claim 1, wherein, The vacuum adsorption platform is provided with small holes, the diameter of the small holes is 0.05mm to 2mm, and the small hole area density of the vacuum adsorption platform is 10 / cm 2 to 300 / cm 2 .

5. The carrier of claim 1, wherein, The flatness of the vacuum adsorption platform is less than 20 μm, and the adsorption force of the vacuum adsorption platform is 0.1-50 N.

6. A method of using the carrier of any one of claims 1-5, wherein, The method comprises: Preparation of coating solution; Adsorption of the silicon wafer after texturing treatment by the vacuum adsorption platform; From the side wall of the groove, the coating solution is coated on the surface of the silicon wafer by the knife head of the slit coating device and dried to prepare a coating layer.

7. The method of claim 6, wherein, The adsorption pressure of the slit coating device is -1-500 kPa, the coating liquid filling time is 0.01-99 s, the coating speed is 0.1-300 mm / s, the coating width is 0.5-37 cm, and the coating thickness is 0.1-3000 μm.

8. The method of claim 6, wherein, The distance between the knife head of the slit coating device and the silicon wafer is 0.1-3000 μm.

9. The method of any one of claims 6-8, wherein, The drying temperature is 60-120 ℃, and the time is 5-20 min.

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