Angle-adjustable wet etching groove processing method, silicon reflector and preparation method thereof

Abstract

The invention discloses an angle-adjustable wet etching groove processing method, a silicon reflector and a preparation method of the silicon reflector. The processing method comprises the following steps: providing a beveled wafer, wherein a preset included angle is formed between the normal direction of a cutting surface and the axial direction of a single crystal ingot; one cutting surface is etched to form a V-shaped groove, and a target included angle formed by one etching surface of the V-shaped groove and the cutting surface is at least determined by an inherent etching angle and a preset included angle. According to the method, the substrate is beveled, the target included angle formed by the cutting surface and the etching surface is adjusted by using the preset included angle formed by beveling, the size of the target included angle can be freely adjusted, the defect that inherent etching angles of some crystal surfaces with better etching effects are difficult to meet application requirements is overcome, preparation of the silicon reflecting mirror is further performed, and the yield of the silicon reflecting mirror is improved. The 111 crystal face can be used for forming the reflecting mirror with the reflecting face and the basic face forming the 45-degree included angle, the problems that other crystal faces are etched coarsely and machining is complex are solved, and the problem that the supporting performance of a reflecting angle is adjusted through a step is solved.

Description

Technical Field

[0001] The invention relates to the field of micro-nano processing, and in particular to an angle-adjustable wet etching groove processing method, a silicon reflector and a preparation method thereof. Background Art

[0002] At present, the wet etching method for preparing silicon-based reflectors usually uses silicon wafers with (100) crystal planes, etches the bevel (111) plane and the crystal plane (100), and the angle between the two etched planes produced by etching is 54.74°. The (111) plane is used as the reflective surface. The properties of the (111) plane are stable and smooth, and can be directly used as an optical reflective mirror.

[0003] 45° reflectors are widely used in optical systems to convert the optical path by 90 degrees and form a 90-degree angle between the incident light and the reflected light. In silicon photonic integrated chips, 45° reflectors can reflect the light in the waveguide vertically out of the chip, which is simpler to adjust the optical path than other angles, such as the 54.74° silicon reflector prepared by wet etching. Due to the integration and cost requirements, silicon-etched 45° reflectors have high application value.

[0004] However, it is difficult to manufacture a 45° mirror surface from a (100) silicon wafer that can be used directly as a reflective surface. The main reason is that the microstructure of the surface of the (100) surface and the (110) surface (the angle between them is 45°) after wet etching is uneven, and both have slight pits (relatively rough), and cannot be directly used as the reflective surface of an optical mirror.

[0005] One solution is to adjust the angle of the base surface. For example, Chinese invention patent CN112764144A provides a design and manufacturing structure and manufacturing method of a 45° silicon reflector. The angle of the reflector is adjusted by using a (111) surface with an angle of 54.74° and a step structure designed on the back of the silicon reflector to form a 45° angle. However, after molding, the upper and lower surfaces are not parallel, and the bottom cannot be stably fixed, lacks support, and is difficult to use.

[0006] Some other technical solutions adopt the method of etching the 110 crystal plane. For example, Chinese invention patent CN112782794A provides a manufacturing structure and manufacturing method for the smoothness of a 45° angle reflector. The rough 45° reflective surface formed by the (110) surface is covered with a molten material and heated to melt to form a smooth plane and then plated with a metal reflective layer, thereby overcoming the problem of excessive roughness of the (110) surface. This technology has the disadvantages of complex structure, high cost, and cannot meet the requirements of pure silicon substrates. It has limitations and is not conducive to the widespread application of silicon-based 45° reflectors.

[0007] There are also some technical solutions that use a wet method combined with cold processing to obtain a polished 110 crystal face to form a 45° mirror. The disadvantages are that the operation is cumbersome, the yield rate is low, and the cost is high, which is also not conducive to the widespread application of silicon-based 45° reflectors. Summary of the invention

[0008] In view of the deficiencies in the prior art, an object of the present invention is to provide a method for processing a wet-etching groove with adjustable angle, a silicon reflector and a method for preparing the same.

[0009] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

[0010] In a first aspect, the present invention provides a method for processing a wet-etched groove with adjustable angle, comprising:

[0011] Providing a beveled wafer, wherein the beveled wafer is formed by cutting a single crystal ingot, and a normal direction of a cutting surface and an axial direction of the single crystal ingot form a preset angle;

[0012] A V-shaped groove is formed on one of the cutting surfaces by wet etching, and a target angle formed between one of the etched surfaces of the V-shaped groove and the cutting surface is at least determined by an inherent etching angle and the preset angle.

[0013] In a second aspect, the present invention further provides a method for preparing a silicon reflector, comprising:

[0014] Providing an oblique-cut silicon wafer, wherein the oblique-cut silicon wafer is formed by cutting a single-crystal silicon ingot whose axial direction is 100 crystal direction, and the normal direction of the cutting surface forms a preset angle with the 100 crystal direction;

[0015] Using wet etching, a V-shaped groove is formed on one of the cutting surfaces along the 111 crystal direction, wherein a target angle formed between one of the etched surfaces of the V-shaped groove and the cutting surface is determined by the 111 crystal direction etching angle and the preset angle;

[0016] The silicon reflector is manufactured by cutting with a V-shaped groove that meets the requirement of the target angle, and another cutting surface opposite to the V-shaped groove serves as a base surface of the silicon reflector.

[0017] In a third aspect, the present invention further provides a silicon reflector, which comprises a reflective surface and a base surface formed on a silicon substrate, wherein the reflective surface is a 111 crystal orientation etched surface formed on a cut surface of the silicon substrate, and the base surface is another cut surface of the silicon substrate;

[0018] The normal direction of the reflection surface and the base surface forms a target angle, the base surface and the 100 crystal direction of the silicon substrate form a preset angle, and the sum of the target angle and the preset angle is the inherent etching angle of the silicon 111 crystal plane.

[0019] Based on the above technical solution, compared with the prior art, the beneficial effects of the present invention at least include:

[0020] The technical solution provided by the present invention bevels the substrate and uses the preset angle formed by the bevel to adjust the target angle formed by the cutting surface and the etching surface. The size of the target angle can be freely adjusted, thereby overcoming the disadvantage that the inherent etching angles of some crystal planes with better etching effects are difficult to meet application requirements. This method is further used to prepare silicon mirrors, and a 111 crystal plane can be used to form a mirror with a reflection surface and a base surface with an angle of 45°, thereby avoiding the problems of rough etching and complex processing of other crystal planes, and also avoiding the support problem of using steps to adjust the reflection angle.

[0021] The above description is only an overview of the technical solution of the present invention. In order to enable those skilled in the art to more clearly understand the technical means of the present application and implement them according to the contents of the specification, the following is a description of the preferred embodiments of the present invention in conjunction with detailed drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of a cutting method of a beveled wafer provided by a typical implementation case of the present invention;

[0023] Figure 2a It is a schematic diagram of the etching state during conventional etching shown in the present invention;

[0024] Figure 2b It is a schematic diagram of the etching state during wet etching provided by a typical implementation case of the present invention;

[0025] Figure 3 It is a schematic diagram of the alignment state of a crystal alignment method provided by a typical implementation case of the present invention;

[0026] Figure 4 It is a schematic diagram of a pattern of a crystal alignment mark and an overlay mark on a wafer surface provided by a typical implementation case of the present invention;

[0027] Figure 5 It is a schematic diagram of an enlarged pattern of a crystal alignment mark and an overlay mark on a wafer surface provided in a typical implementation case of the present invention. DETAILED DESCRIPTION

[0028] In view of the deficiencies in the prior art, the inventor of this case has proposed the technical solution of the present invention after long-term research and extensive practice. The technical solution, its implementation process and principle will be further explained as follows.

[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0030] Moreover, relational terms such as “first” and “second” are merely used to distinguish one component or method step from another with the same name, but do not necessarily require or imply any such actual relationship or order between these components or method steps.

[0031] An embodiment of the present invention provides a method for processing a wet-etched groove with adjustable angle, which comprises the following steps:

[0032] A beveled wafer is provided, wherein the beveled wafer is formed by cutting a single crystal ingot, and a normal direction of a cutting surface and an axial direction of the single crystal ingot are at a preset angle. In some typical representative cases, the cutting state of the beveled wafer is as follows: Figure 1 As shown;

[0033] A V-shaped groove is formed on one of the cutting surfaces by wet etching, and a target angle formed between one of the etched surfaces of the V-shaped groove and the cutting surface is at least determined by an inherent etching angle and the preset angle.

[0034] Figure 2a FIG. 2 shows an inherent etching angle formed by wet etching of a selected crystal orientation when V-groove etching is performed using a conventional forward-cut wafer. The inherent etching angle is determined by the properties of the crystal itself and is difficult to change. When the inherent etching angle deviates from the desired target angle, the application of the etching surface will be hindered. Figure 2b The state of etching using the above method is shown. Due to the bevel cutting, the cutting surface and the axial direction of the crystal have a preset angle. The preset angle changes the actual angle between the etching surface and the cutting surface. Therefore, the angle adjustment can be achieved to eliminate the above deviation for the application of the etching surface.

[0035] Specifically, in some embodiments, the wet etching has a dominant etching crystal direction, and the dominant etching crystal direction is perpendicular to the etching surface; the length direction of the V-shaped groove is perpendicular to the dominant etching crystal direction.

[0036] Due to the existence of crystal orientation, when the length direction of the V-groove is not perpendicular to the dominant etching crystal orientation (e.g. 111 crystal orientation), the etching surfaces on both sides will also be skewed, which is not conducive to production and application. Therefore, in practical applications, it is often necessary to use various means to make the groove direction and the crystal orientation during etching aligned (or orthogonal).

[0037] Regarding the specific etching process, in some embodiments, the wet etching specifically includes the following steps:

[0038] A mask is provided on the etching surface, wherein the mask has a target pattern, and the target pattern corresponds to the position and length direction of the V-shaped groove;

[0039] The exposed area of ​​the target pattern is used as a window, and the exposed cutting surface is wet-etched by using an etching solution.

[0040] The above etching process can be used to accurately align the dominant etching direction (that is, the normal direction of the crystal plane corresponding to the etching surface). Therefore, in some embodiments, the wet etching further includes:

[0041] A plurality of crystal direction alignment marks are arranged along the circumference of the etched surface, wherein the crystal direction alignment marks expose the etched surface;

[0042] Wet etching the etching surface based on the crystal orientation alignment mark to form a plurality of alignment etching areas;

[0043] Taking the radial direction of the etching surface as a dividing line, the alignment etching area is divided into a first side and a second side, and the etching states of the first side and the second side are compared;

[0044] The dominant etching crystal direction is indicated by using the difference in etching states on both sides of the plurality of crystal direction alignment marks, wherein the closer to the dominant etching crystal direction, the smaller the difference in etching states on both sides of the crystal direction alignment mark.

[0045] Specifically, in some embodiments, the radial direction corresponding to a crystal direction alignment mark having the smallest or no difference in etching state between the first side and the second side (i.e., the direction of a line connecting the circular shape of the wafer to the center of the crystal direction alignment mark) or the radial direction between two adjacent crystal direction alignment marks having opposite differences in etching state is used as the indicating direction of the dominant etching crystal direction.

[0046] Normally, the indicated direction found should be perpendicular to the projection direction of the dominant etching direction (i.e. the normal direction of the etched crystal plane) on the wafer. Generally, the deflection angle of two adjacent crystal alignment marks is about 0.1°, and can also be adjusted up and down, such as 0.05-2°, etc.

[0047] For more details, see Figure 3-Figure 5 As shown, in some embodiments, the crystal alignment mark is a rectangle, including a first side and a second side that are not connected (ie Figure 3 The left and right sides of each alignment mark in the etching state are shown in FIG. 1 ), the center line of the rectangle extends along the radial direction of the etching surface, and the etching state comparison method specifically includes:

[0048] Observe perpendicularly to the cutting surface to obtain a projection image of the inclined surface of the mask formed on the first side edge and the second side edge;

[0049] The projection width of the mask inclined surface formed by the first side and the second side in the projection image is compared along the third side to determine the difference in etching state on both sides of the crystal alignment mark. Of course, even if a standard rectangle is not used, the two sides of the center line of the rectangle are kept as straight lines, and the other two sides are symmetrical arcs or other shapes (such as a fan shape, ensuring that the states at the endpoints of the two sides are the same, and the projection width of the etching surface can be compared) can still achieve the same function.

[0050] In some cases, the actual crystal direction of the etched surface in the projection direction of the cutting surface may point to the radial direction represented by two adjacent crystal direction alignment marks. Therefore, the difference between the left and right sides of the two adjacent alignment marks can be used to reflect the relationship between the actual target direction and the directions represented by the two adjacent alignment marks. The target direction must be more biased towards the alignment mark with a smaller difference on both sides. In special cases, when the absolute value of the difference between the two sides of two adjacent alignment marks is equal (but the size relationship between the two sides is opposite), the target direction should be exactly in the middle of the two alignment marks.

[0051] Based on the above principle, a method for calculating the crystal direction in a refined manner is proposed. That is, in some embodiments, when there is no crystal direction alignment mark with no difference in etching state on both sides, the method for finding the indicating direction is specifically expressed as follows:

[0052]

[0053] Among them, α represents the radial angle corresponding to the indicated direction, α1 represents the radial angle corresponding to the adjacent previous crystal direction alignment mark, α2 represents the radial angle corresponding to the adjacent next crystal direction alignment mark, and the three radial angles are all relative to the same reference direction (arbitrarily specifying a reference radial direction will not affect the calculation of the final result), D1 represents the absolute value of the difference in the projection widths on both sides corresponding to the adjacent previous crystal direction alignment mark, and D2 represents the absolute value of the difference in the projection widths on both sides corresponding to the adjacent next crystal direction alignment mark.

[0054] As a special case, when D1 is 0, the indication direction is facing the front crystal alignment mark, and when D2 is 0, the indication direction is facing the back crystal alignment mark.

[0055] certainly, Figure 3The figure shows a schematic diagram of a top view: the blue represents the bevel edge formed by the SiN mask, and the yellow represents the groove width after Si is etched; in fact, there is a relationship between the width of the SiN edge and the corrosion depth. There is an etching selectivity ratio. Observing the width of the SiN edge is equivalent to observing the corrosion depth of Si on both sides. Since the width of SiN is more obvious and easier to observe, it is preferred to observe the difference in actual etching depth on both sides of Si rather than observing Si.

[0056] Of course, if some other methods are adopted, such as using a scanning electron microscope to tilt and observe the actual etching depth on both sides of Si, the same purpose can be achieved, but it is more difficult to operate and the process cost is higher than observing SiN to indirectly reflect this. In addition, SiN is used as the material of the hard mask in the above example, but it is not limited to this. As long as other hard masks can produce selective etching and show different etching states on both sides at different radial angles, they can be used as references for crystal alignment.

[0057] The correct crystal orientation for etching is found through the above method. However, in order to accurately align when etching the V-groove, some other marks are required for overlay positioning. That is, in some embodiments, an overlay mark is also provided next to the crystal orientation alignment mark. The overlay mark includes a first scale line extending in the circumferential direction and a second scale line extending in the radial direction, which are used to indicate the production of the target pattern.

[0058] Of course, the above method is only one type of overlay. Even if the above method is not adopted, various other marking and positioning methods can be used to guide the production of the target pattern when formally etching the V-groove based on finding the correct crystal orientation, which is also within the feasible scope of the present invention.

[0059] Using the above processing method, a second aspect of the embodiment of the present invention further provides a method for preparing a silicon reflector, which comprises the following steps:

[0060] Providing an oblique-cut silicon wafer, wherein the oblique-cut silicon wafer is formed by cutting a single-crystal silicon ingot whose axial direction is 100 crystal direction, and the normal direction of the cutting surface forms a preset angle with the 100 crystal direction;

[0061] Using wet etching, a V-shaped groove is formed on one of the cutting surfaces along the 111 crystal direction, wherein a target angle formed between one of the etched surfaces of the V-shaped groove and the cutting surface is determined by the 111 crystal direction etching angle and the preset angle;

[0062] The silicon reflector is manufactured by cutting with a V-shaped groove that meets the requirement of the target angle, and another cutting surface opposite to the V-shaped groove serves as a base surface of the silicon reflector.

[0063] Correspondingly, an embodiment of the present invention further provides a silicon reflector, which includes a reflective surface and a base surface formed on a silicon substrate, wherein the reflective surface is a 111 crystal orientation etched surface formed on a cut surface of the silicon substrate, and the base surface is another cut surface of the silicon substrate;

[0064] The normal direction of the reflection surface and the base surface forms a target angle, the base surface and the 100 crystal direction of the silicon substrate form a preset angle, and the sum of the target angle and the preset angle is the inherent etching angle of the silicon 111 crystal plane.

[0065] As some typical examples of the above technical solutions, the embodiments provided by the present invention adopt the <100> crystal orientation and <111> A 45° V-groove is prepared by a wet etching process of the crystal direction, and a 45° reflector is made by cutting the V-groove; as is well known in the art, the angle of the V-groove etched by the conventional <100> crystal direction and <111> crystal direction is 54.74°, which has the advantage of simple process preparation, and the side wall (i.e., the etched surface) is realized by the high selectivity ratio of the <100> crystal direction and the <111> crystal direction, so the side wall roughness is very small and can reach the nanometer level; while in this embodiment, the cutting angle of the wafer on the silicon rod is adjusted to change the angle of the V-groove, so as to achieve a 45° angle of the smooth side wall;

[0066] The first step is to require that the wafer be cut 9.74 degrees from the normal direction perpendicular to the crystal rod when cutting the silicon wafer, in order to obtain an oblique wafer;

[0067] The second step is to coat the wafer with a hard mask, generally using SiO2 grown by APCVD or SiN grown by LPCV, or first growing SiO2 and then growing SiN, in order to obtain a dense mask and a high selectivity ratio for Si etching;

[0068] The third step is to perform photolithography on the wafer operated above, align the photomask with the flat edge of the wafer (also called the base edge or positioning edge) as a crystal orientation, and prepare Figure 4 and 5 The crystal alignment mark shown;

[0069] The fourth step is to perform RIE or other types of etching on the wafer after photolithography, transfer the pattern to the hard mask, and complete the degumming and cleaning operations to remove unnecessary soft masks for easy etching;

[0070] The fifth step is to use KOH etching solution to pre-etch the wafer after the hard mask is etched. The etching groove formed by the pre-etching will have different etching states on the left and right sides depending on whether it is directly opposite to (or orthogonal to) the projection direction of the 111 crystal direction in the wafer plane. The specific pre-etching conditions are: concentration of 20% to 40%, etching temperature of 70°C to 90°C, and the wafer is placed in the groove for etching;

[0071] Step 6: After etching to a depth of 100 to 300 μm, take out the crystal alignment mark for observation, measure the projection width of the left and right SiN oblique sides along the outermost edge, and make a judgment according to the crystal alignment rule to find the overlay mark corresponding to the alignment mark with Δx1 = Δx2 (or the closest to this condition);

[0072] Step 7: Overlay according to the overlay mark obtained in step 6, repeat step 3, but note that this time overlay is required instead of aligning the flat edge, and the target pattern corresponding to the V-groove is photolithographically processed;

[0073] Step 8: Repeat step 4 to perform hole etching of the target pattern. RIE / ICP / CCP equipment can be used for etching, and the degumming and cleaning operations are completed.

[0074] In the ninth step, the fifth step is repeated to perform KOH etching on the target pattern, and finally a high-precision 45° V-groove with smooth sidewalls is obtained.

[0075] Subsequently, the reflector can be cut based on the wafer having a plurality of 45° V-grooves. Of course, there is no restriction on the specific subsequent cutting method.

[0076] Of course, in addition to the above examples, it can also be used to prepare mirrors or other devices with various angles, all of which can be designed and prepared using pre-calculated bevel angles; of course, even if the angles are different from those in the above embodiments, the same methods and principles can still be used for crystal alignment and overlay.

[0077] Based on the above embodiments, it can be clearly seen that the technical solution provided by the present invention can freely adjust the size of the target angle by beveling the substrate and utilizing the preset angle formed by the beveling to adjust the target angle formed by the cutting surface and the etching surface, thereby overcoming the disadvantage that the inherent etching angles of some crystal planes with better etching effects are difficult to meet application requirements. This method can be further used to prepare silicon mirrors, and a 111 crystal plane can be used to form a mirror with a reflecting surface and a base surface with an angle of 45°, thereby avoiding the problems of rough etching and complex processing of other crystal planes, and also avoiding the support problem of using steps to adjust the reflection angle.

[0078] It should be understood that the above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for processing a wet-etched groove with adjustable angle, characterized in that: include: Providing a beveled wafer, wherein the beveled wafer is formed by cutting a single crystal ingot, and a normal direction of a cutting surface and an axial direction of the single crystal ingot form a preset angle; A V-shaped groove is formed on one of the cutting surfaces by wet etching, and a target angle formed between one of the etched surfaces of the V-shaped groove and the cutting surface is at least determined by an inherent etching angle and the preset angle.

2. The processing method according to claim 1, characterized in that: The wet etching has a dominant etching crystal direction, and the dominant etching crystal direction is perpendicular to the etching surface; The length direction of the V-shaped groove is perpendicular to the dominant etching crystal direction.

3. The processing method according to claim 2, characterized in that: The wet etching specifically includes: A mask is provided on the etching surface, wherein the mask has a target pattern, and the target pattern corresponds to the position and length direction of the V-shaped groove; The exposed area of ​​the target pattern is used as a window, and the exposed cutting surface is wet-etched by using an etching solution.

4. The processing method according to claim 3, characterized in that: The wet etching further comprises: A plurality of crystal direction alignment marks are arranged along the circumference of the etched surface, wherein the crystal direction alignment marks expose the etched surface; Wet etching the etching surface based on the crystal orientation alignment mark to form a plurality of alignment etching areas; Taking the radial direction of the etching surface as a dividing line, the alignment etching area is divided into a first side and a second side, and the etching states of the first side and the second side are compared; The dominant etching crystal direction is indicated by using the difference in etching states on both sides of the plurality of crystal direction alignment marks, wherein the closer to the dominant etching crystal direction, the smaller the difference in etching states on both sides of the crystal direction alignment mark.

5. The processing method according to claim 4, characterized in that: The radial direction corresponding to the crystal direction alignment mark having the smallest or no difference in etching states between the first side and the second side, or the radial direction between two adjacent crystal direction alignment marks having opposite etching state differences, is used as the indicating direction of the dominant etching crystal direction.

6. The processing method according to claim 5, characterized in that: The crystal orientation alignment mark is a rectangle, including a first side and a second side that are not connected, and the center line of the rectangle extends along the radial direction of the etching surface. The etching state comparison method specifically includes: Observe perpendicularly to the cutting surface to obtain a projection image of the inclined surface of the mask formed on the first side edge and the second side edge; The projection widths of the inclined mask surfaces formed by the first side and the second side in the projection image are compared along the third side to determine the difference in etching states on both sides of the crystal alignment mark.

7. The processing method according to claim 6, characterized in that: When there is no crystal direction alignment mark with no difference in etching state on both sides, the method for finding the indicating direction is specifically expressed as follows: Among them, α represents the radial angle corresponding to the indicated direction, α1 represents the radial angle corresponding to the adjacent previous crystal direction alignment mark, α2 represents the radial angle corresponding to the adjacent next crystal direction alignment mark, and the radial angles are all relative to the same reference direction, D1 represents the absolute value of the difference in the projection widths on both sides corresponding to the adjacent previous crystal direction alignment mark, and D2 represents the absolute value of the difference in the projection widths on both sides corresponding to the adjacent next crystal direction alignment mark.

8. The processing method according to claim 4, characterized in that: An overlay mark is also arranged next to the crystal alignment mark. The overlay mark includes a first scale line extending in the circumferential direction and a second scale line extending in the radial direction, and is used to indicate the production of the target pattern.

9. A method for preparing a silicon reflector, characterized in that: include: Providing an oblique-cut silicon wafer, wherein the oblique-cut silicon wafer is formed by cutting a single-crystal silicon ingot whose axial direction is 100 crystal direction, and the normal direction of the cutting surface forms a preset angle with the 100 crystal direction; Using wet etching, a V-shaped groove is formed on one of the cutting surfaces along the 111 crystal direction, wherein a target angle formed between one of the etched surfaces of the V-shaped groove and the cutting surface is determined by the 111 crystal direction etching angle and the preset angle; The silicon reflector is manufactured by cutting with a V-shaped groove that meets the requirement of the target angle, and another cutting surface opposite to the V-shaped groove serves as a base surface of the silicon reflector.

10. A silicon reflector, characterized in that: It includes a reflection surface and a base surface formed on a silicon substrate, wherein the reflection surface is a 111 crystal orientation etching surface formed on a cutting surface of the silicon substrate, and the base surface is another cutting surface of the silicon substrate; The normal direction of the reflection surface and the base surface forms a target angle, the base surface and the 100 crystal direction of the silicon substrate form a preset angle, and the sum of the target angle and the preset angle is the inherent etching angle of the silicon 111 crystal plane.

Images