CN114114492B - Silicon-based slit assembly and method for assembling silicon-based slit assembly into optical path - Google Patents

Abstract

The invention provides a silicon-based slit component and a method for assembling the silicon-based slit component into an optical path, wherein the silicon-based slit component comprises a silicon substrate, a slit, a trapezoidal groove, a light absorption material layer, a metal protection layer and a disc; the crystal orientation index of the crystal face of the silicon substrate is <111>, and the outline shape is an isosceles triangle; a slit is arranged on the incident surface of the silicon substrate; the emergent surface of the silicon substrate is provided with a trapezoidal groove; the groove width of the trapezoidal groove is gradually increased from the incident surface of the silicon substrate to the emergent surface of the silicon substrate; the slit is communicated with the trapezoidal groove to supply the emitted light to pass through the silicon substrate, and the width of the bottom of the trapezoidal groove is larger than that of the slit; the light absorption material layer is positioned on the incident surface of the silicon substrate; the metal protection layer is positioned on the emergent surface of the silicon substrate; the disc is provided with a first triangular hole matched with the outline shape of the silicon substrate. Compared with a rectangular silicon-based slit, the silicon substrate has the advantage of high integration level, and the silicon-based slit component is compact in structure, high in positioning degree and convenient to assemble into an optical path.

Description

Silicon-based slit assembly and method of assembling the same into an optical path

technical field

The invention relates to the technical field of grating metrology, in particular to a silicon-based slit assembly and a method for assembling the same into an optical path.

Background technique

Traditional optical slits are made on metal sheets by laser or plasma beam processing and etching, so the fineness and thickness uniformity of the slits are affected by the laser pulse energy and metal quality. In addition, for traditional metal thin plate slits, the light-absorbing material on the incident surface is usually borax, which is difficult to achieve high light absorption.

SUMMARY OF THE INVENTION

In order to solve the above problems, the present invention aims to provide a non-metallic silicon-based slit assembly with improved precision.

For achieving the above object, the present invention adopts following concrete technical scheme:

A silicon-based slit assembly, including a silicon substrate, a slit, a trapezoidal groove, a light-absorbing material layer, a metal protective layer and a disc;

The crystal plane of the silicon substrate is <111>, and the outline shape is an isosceles triangle;

The incident surface of the silicon substrate is provided with a slit;

The exit surface of the silicon substrate is provided with a trapezoidal groove, and the longitudinal direction of the slit and the longitudinal direction of the trapezoidal groove are respectively arranged perpendicular to the bottom edge of the contour shape of the silicon substrate; the slit is placed on the center line of the silicon substrate.

From the incident surface of the silicon substrate to the direction of its exit surface, the groove width of the trapezoidal groove gradually increases; on the longitudinal section of the silicon substrate, the slit communicates with the trapezoidal groove for incident light to pass through the silicon substrate, and the trapezoidal groove The width of the groove bottom is greater than the width of the slit;

The light-absorbing material layer is located on the incident surface of the silicon substrate to reduce the reflection of incident light;

The metal protective layer is located on the exit surface of the silicon substrate to prevent stray light from passing through the silicon substrate;

The disc is provided with a through hole which is an isosceles triangle as a whole, and the through hole provides a first triangular hole matching the contour shape of the silicon substrate.

Further, the light absorbing material layer is a black silicon structure.

Further, the material of the metal protective layer is any one of Au, Al, Ni, Ag, and Pt.

Further, a limiting device is connected to the disk, and the limiting device is used to limit the position of the silicon substrate in the thickness direction of the disk.

Further, the through hole includes a second triangular hole opened on the first surface of the disk and a first triangular hole opened on the second surface of the disk, and the first triangular hole and the second triangular hole are communicated to form a through hole, The size of the second triangular hole is smaller than that of the first triangular hole.

Further, it also includes a cylindrical rod fixedly connected with the disc, the axis of the cylindrical rod is perpendicular to the bottom edge of the first triangular hole, and the top angle of the first triangular hole points to the cylindrical rod.

Further, the cylindrical rod is a telescopic rod structure.

A method for assembling a silicon-based slit assembly into an optical path includes the following steps: the axis of a cylindrical rod is vertically arranged in the optical path, and the apex of the silicon substrate is aligned with the apex of an isosceles triangle mounting surface.

The present invention can achieve the following technical effects:

The silicon-based slit component adopts a semiconductor manufacturing process, and the fineness of the slit depends on the lithography precision, so it has the advantage of high precision. In particular, we have grown a light-absorbing material layer and a metal protective layer on the incident surface and the outgoing surface respectively. The former can produce a strong light-absorbing effect, while the latter can prevent light leakage; in addition, an isosceles triangle silicon substrate is used as the Slit carrier, silicon substrates can be prepared in batches on the same silicon wafer, and compared with rectangular silicon-based slits, it has the advantage of high integration, that is, more slits can be prepared on the same size silicon wafer, which can save materials; The isosceles triangle mounting surface is used to embed the slit in it, which improves the assembly capability of the silicon-based slit assembly, and the slit is precisely positioned by using the first triangular hole of the isosceles triangle.

Description of drawings

1 is a schematic cross-sectional structure diagram of a silicon-based slit assembly without a disc according to an embodiment of the present invention;

2 is a schematic longitudinal cross-sectional structural diagram of a silicon-based slit assembly without a disc according to an embodiment of the present invention;

3 is a schematic top-view structural diagram of a silicon-based slit assembly without a disc according to an embodiment of the present invention;

4 is a schematic structural diagram of a triangular silicon substrate in batch processing according to an embodiment of the present invention;

5 is a schematic structural diagram of a rectangular silicon substrate in batch processing according to an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a silicon-based slit assembly with cylindrical rods according to an embodiment of the present invention.

Reference number:

Silicon substrate 1, slit 2, trapezoidal groove 3, light absorbing material layer 4, metal protective layer 5, cylindrical rod 6, second triangular hole 7, first triangular hole 8, disc 9, protrusion 91, vertex 10, The length of the first side is 11, the length of the second side is 12, and the bottom side is 13.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

The silicon-based slit assembly shown in Figures 1-3 and Figure 6 includes a disk 9 and a slit unit. The light absorbing material layer 4, the slit 2, the silicon substrate 1, the trapezoidal groove 3 and the metal protective layer 5 are arranged in sequence from top to bottom in the slit unit. The through hole formed by the slit 2 and the trapezoidal groove 3 runs through the entire silicon-based slit assembly.

The silicon substrate 1 is single crystal, and its crystal plane orientation is <111>. The silicon substrate has opposite incident planes and exit planes, and the thickness between the two planes is generally tens to hundreds of microns. The shape of the silicon substrate is an isosceles triangle. The first side length 11 and the second side length 12 of the silicon substrate are equal in length and are an isosceles triangle; the triangular silicon substrate can be prepared in batches on the same silicon wafer, and compared with the regular rectangular silicon-based slit, it has The advantage of high integration is that more slits can be prepared on the same size silicon wafer. As shown in Figure 4-5, taking a 4-inch silicon wafer as an example, a triangular silicon substrate and a rectangular silicon substrate with a bottom edge of 1 cm and a height of 2 cm are prepared respectively. The former can produce a total of 60 substrates N. The latter can only produce 29 pieces. It has the advantage of saving materials, and breaks through the traditional habit of using rectangular or circular slits.

Wherein, the slit 2 is opened on the incident surface of the silicon substrate 1, and its width is usually between several micrometers and several tens of millimeters. The slit 2 is located on the center line of the triangular silicon substrate, and is perpendicular to the bottom edge 13, so that the structure of the slit unit is symmetrical; the slit 2 allows the incident light to pass through the silicon-based slit assembly.

The trapezoidal groove 3 is located on the exit surface of the silicon substrate 1 , and the longitudinal direction of the slit 2 and the longitudinal direction of the trapezoidal groove 3 are respectively arranged along the longitudinal direction of the silicon substrate 1 . From the incident surface of the silicon substrate 1 to the direction of the exit surface, the groove width of the trapezoidal groove 3 gradually increases. In the longitudinal section of the silicon substrate 1, the top edge of the trapezoidal groove 3 is located inside the silicon substrate. The top edge of the trapezoidal groove 3 is wider than the width of the slit; when there are multiple slits 2 , there is a gap between the two end points of the top edge and the slit 2 , and the silicon substrate 1 is retained. After the incident light passes through the slit 2, the light will diverge, so behind the slit 2 is an isosceles trapezoidal trapezoidal groove 3 to prevent the light from shining on the silicon material. The silicon of the <111> crystal orientation is etched by wet method, and it is naturally trapezoidal when it is made, so that the trapezoidal groove 3 can be quickly obtained.

The light absorbing material layer 4 is located on the incident surface of the silicon substrate 1 to reduce the reflection of incident light. A black silicon structure is preferred, and the black silicon structure is an irregular jungle of silicon pillars. The preparation of the black silicon structure can be performed by dry etching, wet etching, or femtosecond laser processing. The function of the black silicon structure is to absorb incident light and prevent reflection. Black silicon is essentially the same material as the silicon base. Black silicon is just a forest-like structure of silicon (with a small size). The advantage is that it is the same material and does not need to introduce other materials and preparation methods. The light absorbing material layer 4 can also adopt other light absorbing materials with high absorption rate generally greater than 90%.

The metal protective layer 5 is located on the exit surface of the silicon substrate 1 to prevent stray light from passing through the silicon substrate 1 . The material of the metal protective layer 5 is any one of Au, Al, Ni, Ag, and Pt, but is not limited to these. The thickness of the metal reflective layer 5 is set according to actual requirements, and its function is to prevent light from passing through.

Wherein, the circular disk 9 is provided with a through hole which is an isosceles triangle as a whole. The through holes provide first triangular holes 8 matching the contour shape of the silicon substrate 1 . In this way, it is convenient to align the apex of the silicon substrate 1 with the apex of the first triangular hole 8 when the silicon-based slit is used. Embedding the slit unit on the disc 9 is realized. The traditional slit is circular, and the present invention utilizes a triangular silicon substrate, which has the characteristics of material saving and small volume. It can also keep the appearance of the slit in a traditional shape and is versatile. The structure of the through hole may be an isosceles triangle with the same size as the first triangular hole 8, penetrating the disk 9, or may be a stepped structure composed of the first triangular hole and the second triangular hole described later.

Preferably, a circle of protrusions 91 is provided inside the through hole to form a stepped structure on the side surface of one circle of the through hole. In this way, when the aforementioned silicon substrate 1 is placed on the isosceles triangle mounting surface, in the thickness direction of the disk 9, the protrusion 91 acts as a limiting device and has the function of positioning. The silicon substrate 1 is prevented from falling from the first triangular hole 8 of the disk 9 in the thickness direction. For the limiting device, reference may also be made to other technical means in the limiting field, which will not be repeated here.

More preferably, the width of the protrusions 91 is uniform.

Specifically, the disc 9 is provided with a first triangular hole 8 and a second triangular hole 7, both of which are isosceles triangles. The first triangular hole 8 is communicated with the second triangular hole 7; the second triangular hole 7 is located at the center of the first surface of the disc 9, and its shape is the same as that of the triangular silicon substrate 1, but the size is slightly smaller than that of the triangular silicon substrate 1. The second surface and the incident surface of the silicon substrate 1 are located on the same side; the first triangular hole 8 is located at the center of the second surface of the disk 9, and its shape and size are the same as the triangular silicon substrate, so the silicon substrate can be 1 into it. A circle of side surfaces inside the first triangular hole 8 forms the installation surface of the slit unit. The first triangular hole 8 and the second triangular hole 7 together form an isosceles triangular mounting surface with a stepped structure. Preferably, the distance between the first triangular hole 7 and the second triangular hole 8 is equal, and the width of the formed protrusion 91 is uniform.

Preferably, the silicon-based slit assembly further includes a cylindrical rod 6 fixedly connected to the disc 9 , the axis of the cylindrical rod 6 is perpendicular to the bottom edge of the first triangular hole 8 , and the top angle of the first triangular hole 8 points to the cylindrical rod 6 . That is, the cylindrical rod 6 is located on the extension line of the symmetrical center line of the first triangular hole 8 . The cylindrical rod 6 is preferably a telescopic rod structure, which can adjust the position of the slit unit in the optical path.

The disc 9 and the cylindrical rod 6 form an optical path support, and the materials used for the optical path support include but are not limited to iron, copper, steel, alloy, etc. The cylindrical rod 6 is placed vertically in the optical path, and its bottom is fixed on the pedestal of the optical path.

A method for assembling a silicon-based slit assembly into an optical path includes the following steps: the axis of the cylindrical rod 6 is vertically arranged in the optical path, and the vertex of the silicon substrate 1 is aligned with the vertex of the first triangular hole 8 . Specifically, the first triangular hole 8 and the second triangular hole 7 are similar to the triangular silicon substrate 1, and the symmetry lines of the two triangular holes are parallel to the central axis of the cylindrical rod 6, that is, they are both along the optical path. Vertical direction; the slit unit can be embedded in the first triangular hole 8, and only need to align the vertex 10 of the triangular silicon substrate 1 with the vertex of the first triangular hole 8 in the optical path support, that is, the silicon substrate 1 The length of the side formed at the top corner of the first triangular hole 8 conforms to the side length formed at the top corner of the first triangular hole 8; the verticality of the slit can be ensured without additional alignment.

In the description of this specification, description with reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples", etc., mean specific features described in connection with the embodiment or example , structure, material or feature is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, those skilled in the art may combine and combine the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples, without conflicting each other.

Although the embodiments of the present invention have been shown and described above, it is to be understood that the above-described embodiments are exemplary and should not be construed to limit the present invention. Variations, modifications, substitutions, and alterations to the above-described embodiments can be made by those of ordinary skill in the art within the scope of the present invention.

The above specific embodiments of the present invention do not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made according to the technical concept of the present invention shall be included in the protection scope of the claims of the present invention.

Claims (8)

1. The silicon-based slit component is characterized by comprising a silicon substrate (1), a slit (2), a trapezoidal groove (3), a light absorption material layer (4), a metal protection layer (5) and a disc (9);

the crystal direction of the crystal face of the silicon substrate (1) is <111>, and the outline shape is an isosceles triangle;

the slit (2) is formed on the incident surface of the silicon substrate (1);

the exit surface of the silicon substrate (1) is provided with a trapezoidal groove (3), and the length direction of the slit (2) and the length direction of the trapezoidal groove (3) are respectively vertical to the bottom edge (13) of the outline shape of the silicon substrate (1) and are arranged; the slit (2) is arranged on the central line of the silicon substrate (1);

the groove width of the trapezoidal groove (3) is gradually increased from the incident surface to the emergent surface of the silicon substrate (1); the slit (2) is communicated with the trapezoidal groove (3) to supply incident light to pass through the silicon substrate (1), and the width of the bottom of the trapezoidal groove (3) is larger than that of the slit (2);

the light absorption material layer (4) is positioned on the incident surface of the silicon substrate (1) and used for reducing the reflection of the incident light;

the metal protection layer (5) is positioned on the emergent surface of the silicon substrate (1) and used for preventing stray light from penetrating through the silicon substrate (1);

the disc (9) is provided with a through hole which is integrally in the shape of an isosceles triangle, and the through hole is provided with a first triangular hole (8) matched with the outline shape of the silicon substrate (1).

2. A silicon-based slit assembly according to claim 1, wherein the light absorbing material layer (4) is a black silicon structure.

3. Silicon-based slit assembly according to claim 1, wherein the material of the metal protection layer (5) is any one of Au, Al, Ni, Ag, Pt.

4. A silicon-based slit assembly according to claim 1, wherein a position-limiting means is attached to the disc (9) for limiting the position of the silicon substrate (1) in the thickness direction of the disc (9).

5. A silicon-based slit assembly according to claim 1, wherein the through-holes comprise a second triangular hole (7) opened in the first surface of the disc (9) and the first triangular hole (8) opened in the second surface of the disc (9), the second triangular hole (7) and the first triangular hole (8) communicating to form the through-hole, and the size of the second triangular hole (7) is smaller than the size of the first triangular hole (8).

6. Silicon-based slit assembly according to claim 5, further comprising a cylindrical rod (6) fixedly connected to the disc (9), wherein an axis of the cylindrical rod (6) is perpendicular to a bottom side of the first triangular hole (8), and a top angle of the first triangular hole (8) is directed towards the cylindrical rod (6).

7. A silicon-based slit assembly according to claim 6, wherein the cylindrical rod (6) is a telescopic rod structure.

8. A method of assembling a silicon-based slit assembly as defined in any one of claims 6-7 into an optical path, comprising the steps of: the axis of the cylindrical rod (6) is vertically arranged in the light path, and the vertex (10) of the silicon substrate (1) is aligned with the vertex of the first triangular hole (8).

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