45-degree silicon reflector based on chip processing technology
By using a method of biased (100) surface cutting and KOH corrosion liquid opening V-shaped groove structure on the silicon wafer, the problem of difficulty in forming a 45-degree reflector in the prior art is solved, and a high-precision and low-cost 45-degree silicon is achieved. Mirror preparation.
Patent Information
- Application Number
- CN202420478408.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-13
- Publication Date
- 2025-02-11
- Estimated Expiration
- 2034-03-13
AI Technical Summary
The existing silicon wet corrosion technology is difficult to form a 45-degree reflector, and the corrosion surface is prone to stripes and pit points, affecting the quality of the reflector.
The silicon wafer made of 9.74 degrees cut and polished by a bias (100) surface is opened into a V-shaped groove structure through the KOH corrosion liquid, and one corrosion surface is at an angle of 45° with the silicon wafer surface, and optimized the process in combination with chip processing technology.
The high-precision preparation of 45-degree silicon reflectors is achieved, which reduces technical difficulty and cost, improves the performance and reliability of the device, has high output rate, low cost, good repeatability and strong durability.
Smart Images
Figure CN222461723U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of manufacturing reflectors by silicon wet etching, in particular to a 45-degree silicon reflector based on chip processing technology. Background Art
[0002] 45-degree reflectors are widely used in optical systems to convert the optical path by 90 degrees, that is, the incident light and the reflected light form a 90-degree angle. In microsystems, the reflectors are required to reach a scale of millimeters or less than one millimeter. Traditional glass cutting and polishing are very difficult and costly.
[0003] At present, silicon wet etching mirrors usually use (100) crystal silicon wafers, and use the high selectivity of (100) and (111) etching to form a 54.74-degree angle between the (100) and (111) surfaces after etching. The process is mature and stable. However, this method cannot form a 45-degree angle. Some schemes have proposed a method of using the (100) surface to tilt 9.74 degrees, and the (111) surface reflection surface can be obtained by etching. This reflection surface forms a 45-degree angle with the polished surface of the silicon wafer. However, this method has strict requirements on the etching process. Due to crystal defects, mask layers and other reasons, it is easy to cause defects such as stripes and corrosion pits on the (111) reflection surface.
[0004] Therefore, there is an urgent need for a 45-degree silicon reflector based on chip processing technology to solve the quality problem of the 45-degree silicon reflector caused by corrosion surface stripes. Utility Model Content
[0005] The utility model aims to solve the shortcomings in the prior art and proposes a 45-degree silicon reflector based on chip processing technology.
[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:
[0007] A 45-degree silicon reflector based on chip processing technology comprises a silicon wafer made by cutting and polishing at 9.74 degrees on a (100) plane, characterized in that a mask layer is grown on a fireplace tube outside the silicon wafer, a rectangular window is arranged on the front side of the silicon wafer, and two etching surfaces are opened on the outer wall of the rectangular window by KOH etching liquid, the two etching surfaces form a V-shaped groove structure, and one of the etching surfaces forms an angle of 45° with the surface of the silicon wafer.
[0008] As a further solution of the utility model: the back side of the silicon wafer is opened with two etching surfaces by KOH etching solution, the two etching surfaces form a V-shaped groove structure, the V-shaped grooves on the front and back sides of the silicon wafer are staggered, and the etching surfaces of the two V-shaped grooves are parallel.
[0009] As a further solution of the utility model: a 0.2 micron thick gold film is evaporated on the polished surface of the silicon wafer.
[0010] As a further solution of the utility model: the depth of the V-grooves on the front and back surfaces of the silicon wafer is smaller than the thickness of the silicon wafer.
[0011] As a further solution of the utility model: the depth of the V-shaped groove on the back side of the silicon wafer is consistent with the thickness of the silicon wafer.
[0012] As a further solution of the utility model: the depth of the front V-groove is 400 microns, the 45-degree reflection area intersects with the silicon wafer surface, and the angle between the shortest side and the adjacent side is 90 degrees.
[0013] As a further solution of the utility model: the depth of the V-shaped groove on the front side and the V-shaped groove on the back side of the silicon wafer is consistent with the thickness of the silicon wafer.
[0014] The beneficial effects of the utility model are:
[0015] 1. The technical solution of the utility model combines silicon microelectromechanical technology (MEMS technology) and simple optical processing technology, reduces technical difficulty and cost, and improves device performance and reliability; the reflector made on a silicon-based chip has the advantages of small size, high output rate, low cost, good repeatability, strong durability, stable thermal performance, etc.; the optimized process multiplies the output power of the reflector, and the obtained image has high brightness, clearer and more accurate picture quality, and more realistic colors. The produced reflector is an ultra-precision optical component. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 This is a schematic diagram of the silicon wafer structure of a 45-degree silicon reflector based on chip processing technology proposed by the utility model;
[0017] Figure 2 A schematic diagram of the structure of a 45-degree silicon reflector based on chip processing technology proposed by the utility model;
[0018] Figure 3 This is a structural schematic diagram of Example 2 of a 45-degree silicon reflector based on chip processing technology proposed by the utility model;
[0019] Figure 4 This is a schematic structural diagram of a 45-degree silicon reflector in Example 2 of a 45-degree silicon reflector based on chip processing technology proposed by the utility model;
[0020] Figure 5 This is a schematic structural diagram of Example 3 of a 45-degree silicon reflector based on chip processing technology proposed by the utility model;
[0021] Figure 6This is a schematic structural diagram of a 45-degree silicon reflector in Example 3 of a 45-degree silicon reflector based on chip processing technology proposed by the utility model.
[0022] In the figure: 100- (100) plane 9.74 degrees cut and polished silicon wafer, 111-etched surface. DETAILED DESCRIPTION
[0023] The technical solution of this patent is further described in detail below in conjunction with specific implementation methods.
[0024] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.
[0025] Example 1
[0026] A 45-degree silicon reflector based on chip processing technology, such as Figure 1-2 As shown, it includes a silicon wafer made by cutting and polishing at 9.74 degrees on the (100) plane, a mask layer is grown on the outer fireplace tube of the silicon wafer, a rectangular window is set on the front of the silicon wafer, and two etching surfaces are opened on the outer wall of the rectangular window by KOH etching liquid. The two etching surfaces form a V-shaped groove structure, and one of the etching surfaces forms an angle of 45° with the surface of the silicon wafer.
[0027] like Figure 1-2 As shown, the back side of the silicon wafer is opened with two etching surfaces by KOH etching solution, and the two etching surfaces form a V-shaped groove structure. The V-shaped grooves on the front and back sides of the silicon wafer are staggered, and the etching surfaces of the two V-shaped grooves are parallel; a 0.2 micron thick gold film is evaporated on the polished surface of the silicon wafer.
[0028] Use 1% hydrofluoric acid to remove the mask layer to expose the smooth front silicon polished surface, and cut from the bottom of the V-groove on the front and back sides in a direction perpendicular to the surface of the silicon wafer. After cutting, use the etched surface with a 45-degree angle with the front of the silicon wafer as the bottom surface of the reflector to obtain a 45-degree reflector.
[0029] The silicon wafer is 500 microns thick, the mask layer is a silicon dioxide or silicon nitride film, or a double-layer film of silicon dioxide and silicon nitride, the KOH etching solution is a 30% KOH aqueous solution, the etching temperature is 80° C., the etching rate is 40 um / h, and the depth of the V-groove on the front and back sides of the silicon wafer is less than the thickness of the silicon wafer;
[0030] The etching depth of the back side of the silicon wafer is 450 microns, the etching depth of the front side of the silicon wafer is 400 microns, the etching time of the back side of the silicon wafer is 12 hours, and the etching time of the front side is 11 hours. When double-sided V-groove etching is performed, the width of the back side V-groove is adjusted to make the depth of the back side V-groove consistent with the thickness of the silicon wafer; the depth of the front side V-groove is 400 microns. When double-sided V-groove etching is performed, the width of the front side V-groove and the back side V-groove are adjusted to make the depth of the front side V-groove and the back side V-groove consistent with the thickness of the silicon wafer.
[0031] When in use, the etched surface is glued to the workbench as the bottom surface of the reflector, and the front coated surface of the wafer is the reflective surface, so a 45-degree reflector can be formed. Figure 2 As shown, the appearance feature of this reflector is that the shortest side and the adjacent sides are perpendicular to each other.
[0032] Example 2
[0033] A 45-degree silicon reflector based on chip processing technology, such as Figure 3-4 As shown, the depth of the V-groove on the back side of the silicon wafer is consistent with the thickness of the silicon wafer; the depth of the V-groove on the front side is 400 microns, the 45-degree reflection area intersects with the silicon wafer surface, and the shortest side is cut at a 90-degree angle with the adjacent side.
[0034] Example 3
[0035] A 45-degree silicon reflector based on chip processing technology, such as Figure 5-6 As shown, the depths of the V-grooves on the front and back sides of the silicon wafer are consistent with the thickness of the silicon wafer, and the 45-degree reflection area intersects with the front and back sides of the silicon wafer to form a parallelogram reflector structure.
[0036] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.
Claims
1. A 45-degree silicon reflector based on chip processing technology, comprising a silicon wafer cut and polished at 9.74 degrees off (100) plane, characterized in that: A mask layer is grown on the outer fireplace tube of the silicon wafer, a rectangular window is arranged on the front of the silicon wafer, and two etching surfaces are opened on the outer wall of the rectangular window by KOH etching liquid. The two etching surfaces form a V-shaped groove structure, and one of the etching surfaces forms an angle of 45° with the surface of the silicon wafer.
2. A 45-degree silicon reflector based on chip processing technology according to claim 1, characterized in that: The back surface of the silicon wafer is opened with two etching surfaces by KOH etching solution, and the two etching surfaces form a V-shaped groove structure. The V-shaped grooves on the front and back surfaces of the silicon wafer are staggered, and the etching surfaces of the two V-shaped grooves are parallel.
3. A 45-degree silicon reflector based on chip processing technology according to claim 2, characterized in that: A 0.2 micron thick gold film is evaporated on the polished surface of the silicon wafer.
4. The 45-degree silicon reflector based on chip processing technology according to claim 3, characterized in that: The depths of the V-grooves on the front and back surfaces of the silicon wafer are both less than the thickness of the silicon wafer.
5. The 45-degree silicon reflector based on chip processing technology according to claim 4, characterized in that: The depth of the V-shaped groove on the back side of the silicon wafer is consistent with the thickness of the silicon wafer.
6. The 45-degree silicon reflector based on chip processing technology according to claim 5, characterized in that: The depth of the front V-groove is 400 microns, the 45-degree reflection area intersects with the silicon wafer surface, and the angle between the shortest side and the adjacent side is 90 degrees.
7. The 45-degree silicon reflector based on chip processing technology according to claim 6, characterized in that: The depths of the V-shaped grooves on the front side and the back side of the silicon wafer are consistent with the thickness of the silicon wafer.