Method for manufacturing triangular groove echelon gratings with 90-degree vertex angles

Abstract

The invention provides a method for manufacturing triangular groove echelon gratings with 90-degree vertex angles. Each triangular groove echelon grating is composed of a silicon grating structure (1), photoresist (3) and a metal film (4). A manufactured grating groove is a triangle with the vertex angle being 90 degrees, so that the diffraction efficiency higher than that of an echelon grating with the vertex angle being not 90 degrees can be achieved. Each grating structure is produced in an obliquely-cut monocrystalline wafer, the shining angles of the gratings are determined by an obliquely-cut angle for cutting each silicon wafer, and gratings with any blazing angles can be manufactured; according to the 90-degree vertex angles, grooves of silicon gratings with the vertex angles being not 90 degrees are filled with photoresist, then photoetching is conducted again, and the original silicon gratings with the vertex angles being not 90 degrees are converted into the triangular groove gratings with the vertex angles being 90 degrees. According to the manufactured grating structure, the shining face of each grating is a smooth monocrystal silicon <111> grate plane, scattering can be effectively lowered, and the diffraction efficiency of each grating is improved. The purpose that all the gratings have high diffraction efficiency on a broadband is achieved according to the fact that using wave bands can choose to be coated with various different reflecting film layers on the surfaces of the gratings.

Description

technical field

[0001] The invention relates to the field of dispersion elements used in spectroscopic instruments, in particular to a method for manufacturing an echelle grating used in an echelle grating spectrometer for visible light to infrared bands. Background technique

[0002] The echelle grating spectrometer, which has developed rapidly in recent years, uses the echelle grating as the main dispersive element, supplemented by a transverse dispersive element for order separation, and uses an area array CCD to record spectral lines in a wide spectral range (visible light to infrared) at the same time. The entire system is small in size , wide operating wavelength range, high linear dispersion rate and high resolution. As a special type of blazed grating, the main difference between the echelle grating and the usual blazed grating is that the "short side" of the groove is used when the echelle grating works, that is, the blaze angle is usually greater than 45°. [0003...

Examples

Embodiment 1

[0070] Example 1—Using an obliquely cut single crystal silicon wafer to make an echelle grating with a blaze angle of 54.7°:

[0071] Echelle grating preparation method comprises the following steps, see figure 2 ;

[0072] Select the obliquely cut single crystal silicon wafer 1, in order to manufacture an echelle grating with a blaze angle of 54.7°, the off angle is the surface of the obliquely cut silicon wafer and the original surface of the single crystal silicon wafer, namely (110) The angle α between the lattice planes is equal to 35.3°, see image 3 ;

[0073] Silicon nitride (SiNx) film 2 with a thickness of 50nm is plated on a silicon wafer using low-pressure chemical vapor deposition (LPCVD), see Figure 4 ;

[0074] Use the spin coating method to coat the positive photoresist 3 with a thickness of 200nm on the silicon nitride film, see Figure 5 , the thickness of the photoresist is determined according to the thickness of silicon nitride, which needs to be...

Embodiment 2

[0084] Example 2—Using an obliquely cut single crystal silicon wafer to make an echelle grating with a blaze angle of 76°:

[0085] Select obliquely cut monocrystalline silicon wafer 1, and make a blaze angle of 76°. The off-cut angle is the surface of the obliquely cut silicon wafer and the original surface, that is, the angle α between the (110) lattice plane is equal to 14°, see image 3 ;

[0086] Silicon nitride (SiNx) film 2 with a thickness of 50nm is plated on a silicon wafer using low-pressure chemical vapor deposition (LPCVD), see Figure 4 ;

[0087] Use the spin coating method to coat a positive photoresist 3 with a thickness of 100 nm on the silicon nitride film, see Figure 5 , the thickness of the photoresist is determined according to the thickness of silicon nitride, which needs to be greater than the thickness of the silicon nitride film layer 2, choose 100-1000nm;

[0088] Use the mask plate to expose on the ultraviolet lithography machine, and obtain a...

Embodiment 3

[0097] Example 3—Using a single crystal silicon wafer to make an echelle grating with a blaze angle of 54.7°:

[0098] Select monocrystalline silicon wafer 1, because the angle α between the surface of the silicon wafer and the (111) plane is equal to 54.7°. The angle α between the lattice planes is equal to 0°, see Figure 16 ;

[0099] Silicon nitride (SiNx) film 2 with a thickness of 50nm is plated on a silicon wafer using low-pressure chemical vapor deposition (LPCVD), see Figure 4 ;

[0100] Use the spin coating method to coat a positive photoresist 3 with a thickness of 100 nm on the silicon nitride film, see Figure 5 , the thickness of the photoresist is determined according to the thickness of silicon nitride, which needs to be greater than the thickness of the silicon nitride film layer 2, choose 100-1000nm;

[0101] Use the mask plate to expose on the ultraviolet lithography machine, and obtain a photoresist relief pattern consistent with the pattern on the ...

technical field

[0001] The invention relates to the field of dispersion elements used in spectroscopic instruments, in particular to a method for manufacturing an echelle grating used in an echelle grating spectrometer for visible light to infrared bands. Background technique

[0002] The echelle grating spectrometer, which has developed rapidly in recent years, uses the echelle grating as the main dispersive element, supplemented by a transverse dispersive element for order separation, and uses an area array CCD to record spectral lines in a wide spectral range (visible light to infrared) at the same time. The entire system is small in size , wide operating wavelength range, high linear dispersion rate and high resolution. As a special type of blazed grating, the main difference between the echelle grating and the usual blazed grating is that the "short side" of the groove is used when the echelle grating works, that is, the blaze angle is usually greater than 45°. [0003...

Examples

Embodiment 1

[0070] Example 1—Using an obliquely cut single crystal silicon wafer to make an echelle grating with a blaze angle of 54.7°:

[0071] Echelle grating preparation method comprises the following steps, see figure 2 ;

[0072] Select the obliquely cut single crystal silicon wafer 1, in order to manufacture an echelle grating with a blaze angle of 54.7°, the off angle is the surface of the obliquely cut silicon wafer and the original surface of the single crystal silicon wafer, namely (110) The angle α between the lattice planes is equal to 35.3°, see image 3 ;

[0073] Silicon nitride (SiNx) film 2 with a thickness of 50nm is plated on a silicon wafer using low-pressure chemical vapor deposition (LPCVD), see Figure 4 ;

[0074] Use the spin coating method to coat the positive photoresist 3 with a thickness of 200nm on the silicon nitride film, see Figure 5 , the thickness of the photoresist is determined according to the thickness of silicon nitride, which needs to be...

Embodiment 2

[0084] Example 2—Using an obliquely cut single crystal silicon wafer to make an echelle grating with a blaze angle of 76°:

[0085] Select obliquely cut monocrystalline silicon wafer 1, and make a blaze angle of 76°. The off-cut angle is the surface of the obliquely cut silicon wafer and the original surface, that is, the angle α between the (110) lattice plane is equal to 14°, see image 3 ;

[0086] Silicon nitride (SiNx) film 2 with a thickness of 50nm is plated on a silicon wafer using low-pressure chemical vapor deposition (LPCVD), see Figure 4 ;

[0087] Use the spin coating method to coat a positive photoresist 3 with a thickness of 100 nm on the silicon nitride film, see Figure 5 , the thickness of the photoresist is determined according to the thickness of silicon nitride, which needs to be greater than the thickness of the silicon nitride film layer 2, choose 100-1000nm;

[0088] Use the mask plate to expose on the ultraviolet lithography machine, and obtain a...

Embodiment 3

[0097] Example 3—Using a single crystal silicon wafer to make an echelle grating with a blaze angle of 54.7°:

[0098] Select monocrystalline silicon wafer 1, because the angle α between the surface of the silicon wafer and the (111) plane is equal to 54.7°. The angle α between the lattice planes is equal to 0°, see Figure 16 ;

[0099] Silicon nitride (SiNx) film 2 with a thickness of 50nm is plated on a silicon wafer using low-pressure chemical vapor deposition (LPCVD), see Figure 4 ;

[0100] Use the spin coating method to coat a positive photoresist 3 with a thickness of 100 nm on the silicon nitride film, see Figure 5 , the thickness of the photoresist is determined according to the thickness of silicon nitride, which needs to be greater than the thickness of the silicon nitride film layer 2, choose 100-1000nm;

[0101] Use the mask plate to expose on the ultraviolet lithography machine, and obtain a photoresist relief pattern consistent with the pattern on the ...

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