High-efficiency wet etching method for single crystal silicon parts
By controlling the solution flow and etching angle during the wet etching process of monocrystalline silicon components, the problem of uneven etching was solved, achieving efficient and uniform etching results and improving product quality.
Patent Information
- Application Number
- CN202310052417.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-02-02
- Publication Date
- 2025-12-12
- Estimated Expiration
- 2043-02-02
AI Technical Summary
Wet etching causes a reaction layer to form when the etching solution comes into contact with the monocrystalline silicon components, resulting in uneven etching and affecting the surface condition and service life of the product.
By tilting the spray cleaning solution and aerating it in the etching solution circulation tank, the contact angle and position between the monocrystalline silicon components and the solution are controlled to form solution flow and ensure etching uniformity.
Uniform etching of the surface of single-crystal silicon components was achieved, improving product cleanliness and yield, and meeting semiconductor industry standards.
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Figure CN116169010B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of wet etching, in particular to a high-efficiency wet etching method for single crystal silicon parts. BACKGROUND
[0002] Chemical etching technology can achieve what traditional mechanical processing methods cannot. Existing single crystal silicon wet etching mainly includes acid etching and alkali etching. Acid etching is to place single crystal silicon in a mixed solution of hydrofluoric acid, nitric acid and glacial acetic acid, and to strip the surface broken layer through chemical corrosion principle to perform isotropic etching and form 100 crystal lattices. Alkali etching is to perform non-isotropic etching chemical corrosion through alkali solution at a specific temperature to form 111 crystal lattices. Different needs form different microstates and surface states.
[0003] In the domestic semiconductor industry, semiconductor devices need to be able to bear large current interconnections and high temperature risks in work, and the chemical etching technology of semiconductor devices is not mature. The wet etching method will cause a reaction layer to be formed after the etching liquid contacts the single crystal silicon parts, which is not conducive to the continuation of the etching process. The single crystal silicon parts are prone to uneven etching due to the influence of the concentration of the etching liquid at different positions and the etching progress of different parts of the single crystal silicon parts. This will lead to incomplete etching, and the incompletely etched parts will be attached to the surface of the single crystal silicon parts, which will easily lead to incomplete cleaning of the broken layer of the product, uneven surface state and large roughness, and thus affect the use and service life of the product.
[0004] To solve the above problems, a high-efficiency wet etching method for single crystal silicon parts is proposed in the present application. SUMMARY
[0005] (1) Technical problem to be solved
[0006] The purpose of the present application is to overcome the technical problem that the wet etching method will cause a reaction layer to be formed after the etching liquid contacts the single crystal silicon parts, which is not conducive to the continuation of the etching process. The single crystal silicon parts are prone to uneven etching due to the influence of the concentration of the etching liquid at different positions and the etching progress of different parts of the single crystal silicon parts. This will lead to incomplete etching, and the incompletely etched parts will be attached to the surface of the single crystal silicon parts, which will easily lead to incomplete cleaning of the broken layer of the product, uneven surface state and large roughness, and thus affect the use and service life of the product. Therefore, the present application provides a high-efficiency wet etching method for single crystal silicon parts.
[0007] (2) Technical solution
[0008] In order to achieve the purpose of the present application, the technical solution adopted by the present application is as follows:
[0009] A high-efficiency wet etching method for single crystal silicon parts, comprising:
[0010] Step S1, tilt the single crystal silicon component to a first horizontal angle, and spray cleaning solution from the uppermost end of the single crystal silicon component to flush the front surface of the single crystal silicon component;
[0011] Step S2, immerse the flushed single crystal silicon component vertically in at least one circulating pool with etching solution to perform wet etching on the front surface of the single crystal silicon component;
[0012] Step S3, tilt the single crystal silicon component to a second horizontal angle after lifting it away from the etching solution, and spray cleaning solution from the uppermost end of the single crystal silicon component to flush the residual on the front surface of the single crystal silicon component;
[0013] The second horizontal angle is greater than the first horizontal angle.
[0014] Preferably, the step S2 comprises:
[0015] Step S21, immerse the flushed single crystal silicon component completely in the circulating pool with hydrofluoric acid to erode the front surface of the single crystal silicon component;
[0016] Step S22, aerate one side of the bottom of the circulating pool with hydrofluoric acid to form a hydrofluoric acid fluid circulation on both sides of the single crystal silicon component, and stand still for 30s-300s;
[0017] Step S23, lift the single crystal silicon component away from the hydrofluoric acid solution and stand still to drain.
[0018] Preferably, the step S2 further comprises:
[0019] Step S24, immerse the drained single crystal silicon component completely in the circulating pool with etching solution to erode the front surface of the single crystal silicon component;
[0020] Step S25, aerate one side of the bottom of the circulating pool with etching solution to form an etching solution fluid circulation on both sides of the single crystal silicon component, and stand still for 300s-600s;
[0021] Step S26, lift the single crystal silicon component away from the etching solution every certain reaction time to observe the etching effect on the front surface of the single crystal silicon component;
[0022] Step S27, immerse the observed single crystal silicon component completely in the circulating pool with etching solution, and adjust the distance between the single crystal silicon component and the inner wall of the circulating pool according to the observed etching effect;
[0023] Step S28, lift the single crystal silicon component away from the etching solution and stand still to drain.
[0024] Preferably, the step S27 comprises:
[0025] In step S271, if the etching effect on the front surface of the single crystal silicon component is poor, the distance between the front surface of the single crystal silicon component and the inner wall of the circulating pool is shortened.
[0026] In step S272, if the etching effect on the upper and lower parts of the front surface of the single crystal silicon component is inconsistent, the distance between the end of the front surface of the single crystal silicon component with poor etching effect and the inner wall of the circulating pool is shortened.
[0027] Preferably, the cleaning solution is prepared by mixing the alkaline and water, and the mixing ratio is 1:4-1:10.
[0028] Preferably, the first horizontal angle is 15-30 degrees, and the first horizontal angle is 75-90 degrees.
[0029] Preferably, the concentration of the hydrofluoric acid is 0.5-1 mol / L.
[0030] Preferably, the etching solution is prepared by mixing the hydrofluoric acid, nitric acid and glacial acetic acid, and the mixing ratio is 1:5:3-1:5:8.
[0031] Preferably, the reaction time required for lifting the single crystal silicon component out of the etching solution is 30-300 seconds.
[0032] Preferably, the spacing ratio between the single crystal silicon component and the inner wall of the circulating pool on both sides is 1:1-1:2.
[0033] (3) Advantageous effects: The present application discloses a high-efficiency wet etching method for a single crystal silicon component. The single crystal silicon component is arranged in a circulating pool as a separation and etching structure. The aeration method can promote the flow of the soaking solution, and can react with the surface of the single crystal silicon component. The reaction is rapid, stable and sufficient. The position and angle of the single crystal silicon component relative to the inner wall of the circulating pool are adjusted, the flow rate of different parts of the surface of the single crystal silicon component is controlled, and the etching rate of different parts of the single crystal silicon component is mastered. The single crystal silicon component is uniformly etched, the surface cleanliness meets the semiconductor industry standard, the broken layer is removed more cleanly, the operation is simple and easy to control, and the product qualified rate is high. BRIEF DESCRIPTION OF DRAWINGS
[0034] Figure 1 It is a flowchart of the high-efficiency wet etching method for a single crystal silicon component.
[0035] Figure 2 It is a flowchart of the high-efficiency wet etching method for a single crystal silicon component, in which the single crystal silicon component after washing is vertically placed in at least one circulating pool containing hydrofluoric acid for soaking, so as to perform wet etching on the front surface of the single crystal silicon component.
[0036] Figure 3 A flowchart of a process for efficiently wet etching a single-crystal silicon component, in which the rinsed single-crystal silicon component is vertically placed in at least one circulating pool with an etching solution for immersion to wet etch the front surface of the single-crystal silicon component;
[0037] Figure 4 A flowchart of a process for efficiently wet etching a single-crystal silicon component, in which the observed single-crystal silicon component is completely immersed in a circulating pool with an etching solution for immersion, and the spacing between the single-crystal silicon component and the inner wall of the circulating pool is adjusted according to the observed etching effect. DETAILED DESCRIPTION
[0038] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all.
[0039] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all. Figures 1-4 The present application is further described below with reference to the drawings and embodiments:
[0040] Reference Figures 1-4 A method for efficiently wet etching a single-crystal silicon component, comprising:
[0041] Step S1, tilting the single-crystal silicon component to a first horizontal angle, and spraying cleaning solution from the uppermost end of the single-crystal silicon component to rinse the front surface of the single-crystal silicon component;
[0042] Step S2, vertically placing the rinsed single-crystal silicon component in at least one circulating pool with an etching solution for immersion to wet etch the front surface of the single-crystal silicon component;
[0043] Step S3, tilting the single-crystal silicon component to a second horizontal angle after lifting it away from the etching solution, and spraying cleaning solution from the uppermost end of the single-crystal silicon component to rinse the residual on the front surface of the single-crystal silicon component;
[0044] The second horizontal angle is greater than the first horizontal angle.
[0045] Specifically, in the present embodiment, the single-crystal silicon component is placed obliquely, and the cleaning solution can uniformly flow from top to bottom through the front surface of the single-crystal silicon component, so that the front surface of the single-crystal silicon component can be completely cleaned.
[0046] In a preferred embodiment of the present application, the step S2 comprises:
[0047] Step S21, completely immersing the rinsed single-crystal silicon component in a circulating pool with hydrofluoric acid for immersion to etch the front surface of the single-crystal silicon component;
[0048] Step S22, aerate one side of the bottom of the circulating pool with hydrofluoric acid to form a hydrofluoric acid fluid circulation on both sides of the single crystal silicon component, and stand for 30-300 seconds;
[0049] Step S23, lift the single crystal silicon component out of the hydrofluoric acid solution and stand to drain.
[0050] Specifically, in this embodiment, after the single crystal silicon component is completely immersed in the hydrofluoric acid solution, the hydrofluoric acid solution on one side of the single crystal silicon component rises due to the effect of aeration, and flows to the other side of the single crystal silicon component due to gravity, and the hydrofluoric acid solution on the other side continuously replenishes due to sinking, so that a fluid circulation is formed, and the flowing hydrofluoric acid solution can carry away the reaction layer, so that the erosion process on the surface of the single crystal silicon component is efficient.
[0051] In a preferred embodiment of the present application, the step S2 further comprises:
[0052] Step S24, completely immerse the single crystal silicon component after draining in the circulating pool with the erosion solution to erode the front surface of the single crystal silicon component;
[0053] Step S25, aerate one side of the bottom of the circulating pool with the erosion solution to form an erosion solution fluid circulation on both sides of the single crystal silicon component, and stand for 300-600 seconds;
[0054] Step S26, lift the single crystal silicon component out of the erosion solution every certain reaction time to observe the erosion effect on the front surface of the single crystal silicon component;
[0055] Step S27, completely immerse the single crystal silicon component after observation in the circulating pool with the erosion solution, and adjust the distance between the single crystal silicon component and the inner wall of the circulating pool according to the observed erosion effect;
[0056] Step S28, lift the single crystal silicon component out of the erosion solution and stand to drain.
[0057] Specifically, in this embodiment, the flowing erosion solution can carry away the reaction layer, so that the erosion process on the surface of the single crystal silicon component is efficient, and after the erosion solution reacts for 300-600 seconds, part of the surface of the single crystal silicon component is eroded, and the erosion of the remaining part of the single crystal silicon component can be observed by the naked eye, and the area with more remaining distribution represents a poor reaction effect.
[0058] In a preferred embodiment of the present application, step S27 comprises:
[0059] Step S271, if the erosion effect on the front surface of the single crystal silicon component is poor, shorten the distance between the front surface of the single crystal silicon component and the inner wall of the circulating pool;
[0060] If the etching effect of the upper and lower parts of the front surface of the single crystal silicon component is inconsistent, the distance between the end of the front surface of the single crystal silicon component with poor etching effect and the inner wall of the circulating pool is shortened.
[0061] Specifically, in the embodiment, the etching solution circulates in the circulating pool. If the distance between the single crystal silicon component and the inner wall of the circulating pool is shortened, and the amount of solution lifted by aeration remains unchanged, the fluid flow rate in the gap between the front surface of the single crystal silicon component and the inner wall of the circulating pool will be correspondingly increased, promoting the reaction to proceed. The reaction rate can also be increased by increasing the amount of aeration.
[0062] In a preferred embodiment of the present application, the cleaning solution is a mixture of a caustic alkali and water, and the component ratio is 1:4 to 1:10.
[0063] In a preferred embodiment of the present application, the first horizontal angle is 15 to 30 degrees, and the first horizontal angle is 75 to 90 degrees.
[0064] Specifically, in the embodiment, the greater the inclination angle of the single crystal silicon component, the greater the flow rate of the cleaning solution, and the greater the impact force, which is easy to carry away etching residues. The smaller the inclination angle of the single crystal silicon component, the slower the flow rate of the cleaning solution, which can improve the reaction effect. It is worth noting that changing the inclination direction of the single crystal silicon component for spraying can improve the flushing effect.
[0065] In a preferred embodiment of the present application, the concentration of the hydrofluoric acid is 0.5 mol / L to 1 mol / L.
[0066] In a preferred embodiment of the present application, the etching solution is a mixture of hydrofluoric acid, nitric acid, and glacial acetic acid, and the component ratio is 1:5:3 to 1:5:8.
[0067] Specifically, in the embodiment, different ratios and concentrations of the etching solution can obtain different microstates and etching rates, so that the reaction process is controllable.
[0068] In a preferred embodiment of the present application, the reaction time required to lift the single crystal silicon component out of the etching solution is 30 seconds to 300 seconds.
[0069] In a preferred embodiment of the present application, the spacing ratio between the single crystal silicon component and the inner walls of the circulating pool on both sides is 1:1 to 1:2.
[0070] Specifically, in the embodiment, if the upper part of the single crystal silicon component is not well etched, a small gap is formed near the inner wall of the circulating pool, the etching solution formed by aeration is accumulated and accelerated, the local flow rate is increased, and the etching rate of the part is increased. It is worth noting that changing the side of the single crystal silicon component into the etching solution can adjust the etching rate of the single crystal silicon component in different directions, so that each part of the single crystal silicon component tends to be uniformly etched.
[0071] The embodiments of the present application disclose the preferred embodiments, but are not limited thereto. Those skilled in the art can easily understand the spirit of the present application according to the above embodiments, and make different inferences and changes, as long as they do not deviate from the spirit of the present application, which are within the protection scope of the present application.
Claims
1. A high-efficiency wet etching method of a single-crystal silicon component, characterized by, The method comprises the following steps: S1, spraying a cleaning solution from the top of the single-crystal silicon part to flush the front surface of the single-crystal silicon part, while the single-crystal silicon part is tilted to a first horizontal angle; S2, immersing the flushed single-crystal silicon part into a circulating pool containing an etching solution to perform wet etching on the front surface of the single-crystal silicon part; S3, spraying a cleaning solution from the top of the single-crystal silicon part to flush the residual etching solution on the front surface of the single-crystal silicon part, while the single-crystal silicon part is tilted to a second horizontal angle after being lifted away from the etching solution; The second horizontal angle is greater than the first horizontal angle; The step S2 comprises the following steps: S21, immersing the flushed single-crystal silicon part into the circulating pool containing hydrofluoric acid to erode the front surface of the single-crystal silicon part; S22, aerating one side of the bottom of the circulating pool containing hydrofluoric acid to form a hydrofluoric acid fluid circulation on both sides of the single-crystal silicon part, and standing for 30-300 seconds; S23, lifting the single-crystal silicon part away from the hydrofluoric acid solution and standing to drain.
2. A high efficiency wet etching method of a single crystal silicon component as claimed in claim 1, characterized by: The step S2 further comprises the following steps: S24, immersing the drained single-crystal silicon part into a circulating pool containing an erosion solution to erode the front surface of the single-crystal silicon part; S25, aerating one side of the bottom of the circulating pool containing the erosion solution to form an erosion solution fluid circulation on both sides of the single-crystal silicon part, and standing for 300-600 seconds; S26, lifting the single-crystal silicon part away from the erosion solution every certain reaction time to observe the erosion effect on the front surface of the single-crystal silicon part; S27, immersing the observed single-crystal silicon part into the circulating pool containing the erosion solution, and adjusting the distance between the single-crystal silicon part and the inner wall of the circulating pool according to the observed erosion effect; S28, lifting the single-crystal silicon part away from the erosion solution and standing to drain.
3. A high efficiency wet etching method of a single crystal silicon component according to claim 2, wherein If the erosion effects on the upper and lower parts of the front surface of the single-crystal silicon part are inconsistent in the step S27, the distance between the end of the front surface of the single-crystal silicon part with poor erosion effect and the inner wall of the circulating pool is shortened.
4. A high efficiency wet etching method of single crystal silicon components as claimed in claim 1, wherein: The cleaning solution is prepared by mixing a caustic alkali with water, and the mixing ratio is 1:4-1:
10.
5. A high efficiency wet etching method of single crystal silicon components as claimed in claim 1, wherein: The first horizontal angle is 15-30 degrees, and the second horizontal angle is 75-90 degrees.
6. A high efficiency wet etching method of single crystal silicon components as claimed in claim 1, wherein: The concentration of the hydrofluoric acid is 0.5-1 mol / L.
7. A high efficiency wet etching method of a single crystal silicon component as claimed in claim 2, wherein, The erosion solution is prepared by mixing hydrofluoric acid, nitric acid and glacial acetic acid, and the mixing ratio is 1:5:3-1:5:
8.
8. A high efficiency wet etching method of a single crystal silicon component as claimed in claim 2, wherein, The reaction time required for lifting the single-crystal silicon part away from the erosion solution is 30-300 seconds.
9. A high-efficiency wet etching method of a single crystal silicon component according to claim 2 or 3, wherein The distance between the single-crystal silicon part and the inner wall of the circulating pool is 1:1-1:2.
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