Blazed grating manufacturing method

Abstract

The invention provides a blazed grating manufacturing method, which comprises the following steps: providing a substrate, covering the substrate with periodically arranged masks, and etching the substrate by utilizing an incident angle and a rotation angle, taking the masks as a mask and utilizing an ion beam to form a blazed grating. The incident angle is the angle between the first projection of the ion beam on the plane where the normal of the substrate is located and the normal of the substrate, the rotation angle is the angle between the second projection of the ion beam on the plane where the surface of the substrate is located and the tangent line of the surface of the substrate, and the anti-blazing angle of the blazed grating is determined according to the incident angle and the rotation angle. Therefore, the shielding effect of the mask can be reduced by using the incident angle and the rotation angle, so that the purpose of controlling the angle of the anti-blazing angle is achieved, the angle of the anti-blazing angle is controllable, the angle of the anti-blazing angle is increased by controlling the incident angle and the rotation angle, and finally the diffraction efficiency of the blazed grating is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductors, and in particular to a method for manufacturing a blazed grating. Background Art

[0002] With the rapid development of semiconductor technology, blazed gratings are increasingly widely used. For example, blazed gratings can be used in augmented reality or virtual reality scenarios, such as optical transmission near-eye display technology included in augmented reality or virtual reality scenarios.

[0003] Theoretically, the diffraction efficiency of the +1st order of the blazed grating is 100%, but in reality, the diffraction efficiency of the +1st order of the blazed grating is only 65%-80%. This is because the anti-blaze angle of the blazed grating is not vertical, causing part of the light to be absorbed or reflected.

[0004] Therefore, there is an urgent need for a method to improve the diffraction efficiency of a blazed grating. Summary of the invention

[0005] In view of this, the purpose of the present application is to provide a method for manufacturing a blazed grating, which can increase the anti-blaze angle and improve the diffraction efficiency of the blazed grating.

[0006] The present application provides a method for manufacturing a blazed grating, the method comprising:

[0007] Providing a substrate, wherein the substrate is covered with periodically arranged masks;

[0008] By utilizing the incident angle and the rotation angle, the mask is used as a mask and the substrate is etched using an ion beam to form a blazed grating; the incident angle is the angle between a first projection of the ion beam on a plane where the normal of the substrate is located and the normal of the substrate, and the rotation angle is the angle between a second projection of the ion beam on a plane where the surface of the substrate is located and a tangent to the surface of the substrate, and the anti-blazed angle of the blazed grating is determined based on the incident angle and the rotation angle.

[0009] Optionally, the periodically arranged mask includes a mask period, a mask line width and a mask height; the blazed grating includes a blaze angle, a reverse blaze angle and a grating height;

[0010] The reverse blaze angle of the blazed grating is determined according to the incident angle and the rotation angle, comprising:

[0011]

[0012]

[0013] Among them, α is the rotation angle, β is the blaze angle, γ is the anti-blaze angle, θ is the incident angle, a is the mask period, b is the mask line width, and h is the mask height.

[0014] Optionally,

[0015]

[0016] Optionally, the ratio of the mask etching rate to the substrate etching rate is k;

[0017]

[0018] Optionally,

[0019]

[0020] Among them, h 1 is the grating height.

[0021] Optionally, the direction of the acute angle formed by the ion beam and the plane where the surface of the substrate is located is the same as the direction of the blaze angle.

[0022] Optionally, the range of the mask period is [200 nanometers, 10 micrometers], the range of the mask line width is [5%, 80%] of the mask period, and the mask height is greater than or equal to the product of the grating height and k.

[0023] Optionally, the rotation angle is not 0.

[0024] Optionally, the rotation angle has an angle range of [-90°, 90°].

[0025] Optionally, the material of the mask is the same as that of the substrate.

[0026] Optionally, the material of the substrate may be Al 2 O 3 , Ga 2 O 3 、 2 O 3 , Si, SiO 2 、Si 3 N 4 , quartz and TiO 2 One or more of .

[0027] Optionally, when the rotation angle is determined, the positive or negative value of the incident angle affects the direction of the blaze angle, but does not affect the size of the blaze angle, the size of the anti-blaze angle, and the size of the grating height.

[0028] Optionally, when the incident angle is determined, the positive or negative value of the rotation angle does not affect the direction of the blaze angle, the size of the blaze angle, the size of the anti-blaze angle, and the size of the grating height.

[0029] Optionally, when the rotation angle is 0, the lateral etching rate of the substrate is greater than the lateral etching rate of the substrate when the rotation angle is not 0.

[0030] Optionally, the method further comprises:

[0031] A first etching gas is introduced into the discharge chamber, and a second etching gas is introduced into the etching chamber. The substrate is located in the etching chamber, and the first etching gas is used to form plasma.

[0032] Optionally, the first etching gas includes one or more of an inert gas, a fluorine-based gas, a chlorine-based gas, a bromine-based gas, nitrogen or oxygen, and the second etching gas includes one or more of a fluorine-based gas, a chlorine-based gas, a bromine-based gas or oxygen.

[0033] Optionally, the gas flow range of the first etching gas is [10 sccm, 200 sccm], and the gas flow range of the second etching gas is [50 sccm, 5000 sccm].

[0034] Optionally, the beam energy range is [50V, 600V].

[0035] Optionally, the accelerating voltage is 20% of the beam energy.

[0036] Optionally, the beam current range is [50mA, 1200mA].

[0037] The present application provides a method for manufacturing a blazed grating, the method comprising: providing a substrate, the substrate being covered with a periodically arranged mask, utilizing an incident angle and a rotation angle, using the mask as a mask, and using an ion beam to etch the substrate to form a blazed grating. The incident angle is the angle between the first projection of the ion beam on the plane where the normal of the substrate is located and the normal of the substrate, and the rotation angle is the angle between the second projection of the ion beam on the plane where the surface of the substrate is located and the tangent of the surface of the substrate, and the anti-blaze angle of the blazed grating is determined according to the incident angle and the rotation angle. In this way, by utilizing the incident angle and the rotation angle, the shielding effect of the mask can be reduced, thereby achieving the purpose of controlling the angle of the anti-blaze angle, realizing the controllability of the anti-blaze angle, thereby increasing the angle of the anti-blaze angle by controlling the incident angle and the rotation angle, and ultimately improving the diffraction efficiency of the blazed grating. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 A schematic flow chart of a method for manufacturing a blazed grating provided in an embodiment of the present application is shown;

[0040] Figure 2 A structural schematic diagram showing a manufacturing process of a blazed grating provided in an embodiment of the present application;

[0041] Figure 3 A schematic diagram showing an incident angle provided by an embodiment of the present application is shown;

[0042] Figure 4 A schematic diagram showing a rotation angle provided by an embodiment of the present application is shown;

[0043] Figure 5 A schematic cross-sectional structure diagram of a substrate and a mask provided in an embodiment of the present application is shown;

[0044] Figure 6 A schematic cross-sectional structure diagram of a blazed grating provided in an embodiment of the present application is shown;

[0045] Figure 7 A schematic cross-sectional structure diagram of another blazed grating provided in an embodiment of the present application is shown;

[0046] Figure 8 A schematic cross-sectional structure diagram of another blazed grating provided in an embodiment of the present application is shown;

[0047] Fig. 9 A schematic cross-sectional structure diagram of another blazed grating provided in an embodiment of the present application is shown;

[0048] Fig.10 A schematic diagram of the cross-sectional structure of another blazed grating provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0049] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0050] In the following description, many specific details are set forth to facilitate a full understanding of the present application, but the present application may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0051] This application is described in detail with reference to schematic diagrams. When describing the embodiments of this application in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of this application. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0052] With the rapid development of semiconductor technology, optical transmission near-eye display technology included in augmented reality or virtual reality scenes has also been vigorously developed. Optical transmission near-eye display technology includes grating optical waveguide technology. Grating optical waveguide uses the multi-slit diffraction of the grating to disperse the light and the total internal reflection characteristics of the waveguide medium to realize the transmission of the imaging light beam. When the light is incident on the grating surface at a certain angle, the grating will perform spatial periodic modulation on the amplitude or phase of the incident light wave, and the light will diffract out of the grating surface from several different directions. Because grating optical waveguides have the advantages of large field of view, good display effect, small size, light weight, and low mass production cost, they are considered to be the must-have optical solution for consumer-grade augmented reality glasses or virtual reality glasses. However, the development of grating optical waveguides is also subject to some limitations, such as relatively low optical efficiency and serious light efficiency loss.

[0053] Blazed gratings can be used in augmented reality or virtual reality scenes. Blazed gratings are phase-type gratings that can separate the central maximum of diffraction from a single grooved surface and the interference zero-order main maximum between the grooved surfaces, thereby concentrating the light energy on the required first-order diffraction spectrum. Because it has the characteristics of zero-order splitting and easy to satisfy the missing order, the diffraction efficiency is very high. Theoretically, the diffraction efficiency of the +1 order of the blazed grating is 100%, but in fact, the diffraction efficiency of the +1 order of the blazed grating is only 65%-80%, because the anti-blaze angle of the blazed grating is not vertical, resulting in part of the light being absorbed or reflected.

[0054] There are currently two methods for preparing blazed gratings. One is to use the "pattern transfer" technology to transfer the prefabricated blazed grating template to the photoresist, and then completely transfer the pattern to the etched material through vertical chemical etching. However, this method usually makes the corners connected in an arc shape, and it is impossible to obtain a blazed grating with a vertical anti-blazed surface. The other is to use the "mechanical engraving" method to engrave grooves on the etched material, but this is an ultra-precision processing technology with extremely high requirements for machinery and working environment. Any slight disturbance will cause the loss of engraving accuracy, and mass production is extremely difficult.

[0055] Therefore, there is an urgent need for a method to improve the diffraction efficiency of a blazed grating.

[0056] Based on this, the present application provides a method for manufacturing a blazed grating, the method comprising: providing a substrate, the substrate being covered with a periodically arranged mask, utilizing an incident angle and a rotation angle, using the mask as a mask, and using an ion beam to etch the substrate to form a blazed grating. The incident angle is the angle between the first projection of the ion beam on the plane where the normal of the substrate is located and the normal of the substrate, and the rotation angle is the angle between the second projection of the ion beam on the plane where the surface of the substrate is located and the tangent of the surface of the substrate. The anti-blaze angle of the blazed grating is determined according to the incident angle and the rotation angle. In this way, by utilizing the incident angle and the rotation angle, the shielding effect of the mask can be reduced, thereby achieving the purpose of controlling the angle of the anti-blaze angle, realizing the controllability of the anti-blaze angle, thereby increasing the angle of the anti-blaze angle by controlling the incident angle and the rotation angle, and ultimately improving the diffraction efficiency of the blazed grating.

[0057] In order to better understand the technical solution and technical effects of the present application, specific embodiments will be described in detail below with reference to the accompanying drawings.

[0058] See also Figure 1 , which is a schematic flow chart of a method for manufacturing a blazed grating provided in an embodiment of the present application.

[0059] The manufacturing method of the blazed grating provided in this embodiment can be applied to semiconductor equipment, such as ion beam etching (IBE) equipment, wherein the IBE equipment includes a discharge chamber and an etching chamber, the discharge chamber is used to introduce a first etching gas, and the first etching gas is ionized into plasma and then led out to the etching chamber through a grid, and then neutralized by electrons generated by a neutralizer, thereby achieving etching. At the same time, a second etching gas is introduced into the etching chamber to assist in etching.

[0060] The method for manufacturing the blazed grating provided in this embodiment comprises the following steps:

[0061] S101, providing a substrate.

[0062] In the embodiments of the present application, the substrate may be a dielectric material or a high refractive index material. For example, the substrate may be made of Al 2 O 3 , Ga 2 O 3 、 2 O 3 , Si, SiO 2 、Si 3 N 4 , quartz and TiO 2 One or more of .

[0063] A patterned mask may be covered on the substrate, and the mask may be arranged periodically, so that a periodic blazed grating may be formed using the periodically arranged mask.

[0064] refer to Figure 2 As shown, Figure 2 The schematic diagram of the structure of the blazed grating at a certain angle (Angled View) during the manufacturing process, the material is the substrate, and the mask is arranged periodically. The substrate is set in the etching chamber.

[0065] In the embodiments of the present application, the material of the mask can be the same as that of the substrate, in which case the mask is a homogeneous mask. For example, the material of the substrate is Si, and the material of the mask is Si. The material of the mask can be different from that of the substrate, in which case the mask is a heterogeneous mask. For example, the material of the substrate is Si, and the material of the mask is photoresist.

[0066] S102, using the incident angle and the rotation angle, taking the mask as a mask, and using the ion beam to etch the substrate to form a blazed grating.

[0067] In the embodiment of the present application, the substrate can be etched by using an ion beam extracted from a discharge chamber. The incident ion beam can be referred to as an ion beam. Specifically, the substrate can be etched by using an incident angle and a rotation angle with a mask as a mask, thereby forming a blazed grating.

[0068] When the ion beam etches the substrate with a mask at an inclined incident angle, the substrate at different positions is etched to different degrees due to the obstruction of the mask. The substrate portion not blocked by the mask is etched downward first, and the remaining substrate portion is gradually etched as the mask disappears. As the mask is completely consumed, a blazed grating with a certain groove shape is formed. The incident angle is the angle between the first projection of the ion beam on the plane where the normal line of the substrate is located and the normal line of the substrate, refer to Figure 3 , which is a schematic cross-sectional view of the blazed grating during the manufacturing process, the dotted line perpendicular to the substrate is the normal of the substrate, and the incident angle is θ.

[0069] However, when etching the substrate at an inclined incident angle, the shielding effect of the mask is strong, resulting in a smaller anti-blaze angle of the blazed grating. Therefore, the substrate can be etched in combination with a rotation angle. The rotation angle is the angle between the second projection of the ion beam on the plane where the surface of the substrate is located and the tangent line of the surface of the substrate. Figure 4 , which is a top view schematic diagram of the blazed grating during the manufacturing process, the dotted line at right angles to the mask is the tangent line of the surface of the substrate, and the rotation angle is α.

[0070] That is to say, by combining the direction of the ion beam with the rotation angle based on the incident angle, the shielding effect of the mask can be reduced, and the lateral etching rate can be changed without changing the longitudinal etching rate of the etched material, ultimately achieving the controllable anti-blaze angle, that is, achieving the controllable anti-blaze angle.

[0071] In the embodiment of the present application, the anti-blaze angle of the blazed grating can be determined according to the incident angle and the rotation angle, that is, the anti-blaze angle can be increased by controlling the incident angle and the rotation angle, thereby ultimately improving the diffraction efficiency of the blazed grating.

[0072] In practical applications, the substrate is etched simultaneously in combination with the incident angle and the rotation angle, that is, the substrate is etched once using the incident angle and the rotation angle.

[0073] Specifically, the structural parameters of the periodically arranged mask include mask period, mask line width and mask height. Figure 5 As shown, the material of the substrate is Si, the material of the mask is Si, the mask height is 600nm, the mask line width is 80nm, and the mask period is 400nm.

[0074] The structural parameters of the blazed grating include the blaze angle, anti-blaze angle and grating height.

[0075] The anti-blaze angle can be calculated using the following formula:

[0076]

[0077]

[0078] Among them, α is the rotation angle, β is the blaze angle, γ is the anti-blaze angle, θ is the incident angle, a is the mask period, b is the mask line width, and h is the mask height.

[0079] In the above formula, 0≤c≤ab, when c=0, γ=90°, and when 0<c<ab, γ<90°. That is to say, when c=0, the anti-blaze angle is 90°, so the optimal incident angle and the optimal rotation angle can be reversed through the expected anti-blaze angle, so that the substrate can be subsequently etched using the optimal incident angle and the optimal rotation angle, so as to finally achieve an anti-blaze angle of 90°.

[0080] In an embodiment of the present application, the rotation angle is not 0, that is, α≠0. When the rotation angle is 0, the second projection of the ion beam on the substrate surface coincides with the tangent of the substrate surface, and the substrate is still etched at the incident angle. At this time, a small anti-blaze angle still occurs.

[0081] In an embodiment of the present application, the lateral etching rate of the substrate when the rotation angle is 0 is greater than the lateral etching rate of the substrate when the rotation angle is not 0. That is, compared with etching the substrate without setting the rotation angle, the lateral etching rate of the substrate is reduced after the rotation angle is set, which helps to form an anti-blaze angle close to 90°.

[0082] In practical applications, the lower electrode in the etching chamber can realize self-rotation to control the rotation angle, and the rotation angle has an angle range of [-90°, 90°] and is not 0.

[0083] The lower electrode in the etching chamber can realize revolution to control the incident angle, and the angle range of the incident angle is [-90°, 90°]. The limitation of the etching chamber itself makes the revolution only operate in the third and fourth quadrants, that is, when the incident angle is 0, the first projection of the ion beam on the plane where the normal line of the substrate is located coincides with the normal line of the substrate.

[0084] In practical applications, when the line direction of the substrate forms a certain angle of I° with the vertical line direction of the ion beam incident, the lower electrode needs to rotate -I°. This can achieve that the line direction of the substrate is parallel to the vertical line direction of the ion beam incident, which is beneficial for the subsequent calculation of the incident angle and rotation angle.

[0085] In practical applications, when When the mask has no shielding effect, it is meaningless to set the rotation angle. Therefore, the incident angle can be kept to satisfy the above relationship, so that the anti-blaze angle is close to 90°.

[0086] In the embodiment of the present application, when α is the rotation angle, β is the blaze angle, γ is the anti-blaze angle, θ is the incident angle, a is the mask period, b is the mask line width, and h is the mask height, the grating height of the blazed grating can be obtained according to the blaze angle, the anti-blaze angle and the mask period. The specific formula is as follows:

[0087]

[0088] Among them, h 1 is the grating height.

[0089] In the embodiment of the present application, the materials of the substrate and the mask affect the ratio of the mask etching rate to the substrate etching rate. If the ratio of the mask etching rate to the substrate etching rate is k, the mask height is greater than or equal to the product of the grating height and k, that is, h≥kh 1 , where k ranges from [0.1, 15].

[0090] In the embodiment of the present application, the size of the blaze angle can be determined according to the incident angle and the ratio of the mask etching rate to the substrate etching rate, specifically referring to the following formula:

[0091]

[0092] In practical applications, the range of mask period is [200 nanometers, 10 micrometers], that is, the range of mask period is 200nm-10μm. The range of mask line width is [5%, 80%] of the mask period, that is, the range of mask line width is 5%-80% of the mask period.

[0093] In the embodiment of the present application, the direction of the acute angle formed by the ion beam and the plane where the surface of the substrate is located is the same as the direction of the blaze angle. In other words, the incident direction of the ion beam will affect the direction of the blaze angle, so the direction of the blaze angle can be adjusted by adjusting the direction of the ion beam.

[0094] In the embodiment of the present application, when the incident angle is determined, the positive or negative rotation angle does not affect the direction of the blaze angle, the size of the blaze angle, the size of the anti-blaze angle, and the size of the grating height. In other words, the positive or negative rotation angle will not have a substantial impact on the blaze grating, that is, as long as the second projection of the ion beam on the plane where the surface of the substrate is located and the tangent of the surface of the substrate are at a fixed angle, the second projection of the ion beam on the plane where the surface of the substrate is located on either side of the tangent will not affect the direction of the blaze angle, the size of the blaze angle, the size of the anti-blaze angle, and the size of the grating height.

[0095] In the embodiment of the present application, when the rotation angle is determined, the positive or negative of the incident angle affects the direction of the blaze angle, but does not affect the size of the blaze angle, the size of the reverse blaze angle, and the size of the grating height. In other words, the positive or negative of the incident angle only affects the direction of the blaze angle, but has no effect on the size of the blaze angle, the size of the reverse blaze angle, and the size of the grating height, that is, as long as the first projection of the ion beam on the plane where the normal of the substrate is located is at a fixed angle to the normal of the substrate, the first projection of the ion beam on the plane where the normal of the substrate is located on either side of the normal will not affect the size of the blaze angle, the size of the reverse blaze angle, and the size of the grating height.

[0096] In the embodiment of the present application, in order to etch the substrate, a first etching gas may be introduced into the discharge chamber and a second etching gas may be introduced into the etching chamber, thereby etching the substrate using the first etching gas and the second etching gas.

[0097] Specifically, the first etching gas includes one or more of an inert gas, a fluorine-based gas, a chlorine-based gas, a bromine-based gas, nitrogen or oxygen. The second etching gas includes one or more of a fluorine-based gas, a chlorine-based gas, a bromine-based gas or oxygen. The inert gas may include He, Ne, Ar, Kr and Xe. The fluorine-based gas may include CF 4 CF 8 , CHF3 , BF 3 and SF 6 Chlorine-based gases can include HCl, CCl 4 , BCl 3 and Cl 2 etc. The bromine-based gas may include HBr and the like.

[0098] In practical applications, the gas flow range of the first etching gas is [10 sccm, 200 sccm], so that the pressure of the discharge chamber can reach 0.1-5 mtor, thereby increasing the mean free path of ions and facilitating etching.

[0099] The gas flow range of the second etching gas is [50sccm, 5000sccm], so that the pressure of the etching chamber can reach 0.1-10mtor, thereby increasing the mean free path of ions and facilitating etching.

[0100] In the embodiment of the present application, the range of beam energy is [50 V, 600 V]. The greater the beam energy, the greater the production capacity, but too high beam energy will lead to increased sidewall damage, so the beam energy can be selected according to actual conditions.

[0101] In the embodiment of the present application, the acceleration voltage is 20% of the beam energy, which can keep the beam divergence angle at 5°-15°, improve the ion utilization rate in the plasma, and facilitate etching.

[0102] In the embodiment of the present application, the range of the beam current is [50mA, 1200mA]. The larger the beam current, the greater the productivity, but too high a beam current will increase the degree of sidewall damage, so the beam current can be selected according to actual conditions.

[0103] In practical applications, the beam current generated by the neutralizer is equal to the beam current of the first etching gas, which can achieve complete neutralization, reduce charge accumulation, keep the beam divergence angle at 5°-15°, improve the ion utilization rate in the plasma, and facilitate etching.

[0104] The following are five methods for adjusting the structural parameters of the blazed grating at different incident angles and rotation angles when etching the substrate:

[0105] The first condition is to use Si as a homogeneous mask, with a mask height of 600nm, a mask line width of 80nm, and a mask period of 400nm. The incident angle is 40°, and the rotation angle is 0. The first etching gas is Ar, and the gas flow rate of Ar is set to 24sccm, the beam energy is 400V, the acceleration voltage is 80V, and the beam current is 510mA. After the Ar is ionized to form a plasma, it is neutralized by the grid and the substrate is etched for 420s. The grating height of the formed blazed grating is 270nm, the blaze angle is 57°, and the anti-blaze angle is 50°. Figure 6 shown.

[0106] The second condition is to use Si as a homogeneous mask, with a mask height of 600nm, a mask line width of 80nm, and a mask period of 400nm. The incident angle is 35° and the rotation angle is 49°. The first etching gas is Ar, and the gas flow rate of Ar is set to 24sccm, the beam energy is 400V, the acceleration voltage is 80V, and the beam current is 510mA. After the Ar is ionized to form a plasma, it is neutralized by the grid and the substrate is etched for 315s. The grating height of the formed blazed grating is 213nm, the blaze angle is 31°, and the anti-blaze angle is 78°. Figure 7 As shown. According to the anti-blaze angle of 78° and the formula, the theoretical rotation angle is 49.16°, which is very different from the rotation angle of the second condition. Compared with the first condition, under the same mask morphology and the same incident angle, the anti-blaze angle can be increased by adding a rotation angle, that is, the verticality of the anti-blaze angle can be improved.

[0107] The third condition is to use Si as a homogeneous mask, with a mask height of 600nm, a mask line width of 80nm, and a mask period of 400nm. The incident angle is 35° and the rotation angle is 41°. The first etching gas is Ar, and the gas flow rate of Ar is set to 24sccm, the beam energy is 400V, the acceleration voltage is 80V, and the beam current is 510mA. After the Ar is ionized to form a plasma, it is neutralized by the grid and the substrate is etched for 342s. The grating height of the formed blazed grating is 240nm, the blaze angle is 31°, and the anti-blaze angle is 89°. Figure 8 As shown. Based on the anti-blaze angle of 89° and the formula, the theoretical rotation angle is 40.4°, which is very different from the rotation angle of the third condition. Compared with the second condition, under the same mask morphology and the same incident angle, the anti-blaze angle can be increased by adjusting the rotation angle, so that the anti-blaze surface of the blazed grating is completely close to vertical.

[0108] The fourth condition is to use Si as a homogeneous mask, with a mask height of 600nm, a mask line width of 80nm, and a mask period of 400nm. The incident angle is 40°, and the rotation angle is 51°. The first etching gas is Ar, and the gas flow rate of Ar is set to 24sccm, the beam energy is 400V, the acceleration voltage is 80V, and the beam current is 510mA. After the Ar is ionized to form a plasma, it is neutralized by the grid and the substrate is etched for 354s. The grating height of the formed blazed grating is 269nm, the blaze angle is 34°, and the anti-blaze angle is 89°. Fig. 9 As shown. According to the anti-blaze angle of 89° and the formula, the theoretical rotation angle is 50.53°, which is very different from the rotation angle of the fourth condition. Compared with the third condition, under the same mask morphology, by adjusting the incident angle and the rotation angle, a blazed grating with different blaze angles and an anti-blaze angle close to 90° can be obtained.

[0109] The fifth condition is to use Si as a homogeneous mask, with a mask height of 450nm, a mask line width of 60nm, and a mask period of 320nm. The incident angle is 34°, and the rotation angle is 31°. The first etching gas is Ar, and the gas flow rate of Ar is set to 24sccm, the beam energy is 400V, the acceleration voltage is 80V, and the beam current is 510mA. After the Ar is ionized to form a plasma, it is neutralized by the grid and the substrate is etched for 270s. The grating height of the formed blazed grating is 168nm, the blaze angle is 28°, and the anti-blaze angle is 89°. Fig.10 As shown. According to the anti-blaze angle of 89° and the formula, the theoretical rotation angle is 31.1°, which is very close to the rotation angle of the fifth condition. Compared with the third and fourth conditions, under different mask morphologies, blazed gratings with different blaze angles and anti-blaze angles close to 90° can be obtained by adjusting the incident angle and the rotation angle, that is, the blaze angle and anti-blaze angle of the blazed grating can be controlled by the incident angle and the rotation angle.

[0110] It can be seen that the present application provides a method for manufacturing a blazed grating, the method comprising: providing a substrate, the substrate being covered with a periodically arranged mask, utilizing an incident angle and a rotation angle, using the mask as a mask, and utilizing an ion beam to etch the substrate to form a blazed grating. The incident angle is the angle between the first projection of the ion beam on the plane where the normal of the substrate is located and the normal of the substrate, and the rotation angle is the angle between the second projection of the ion beam on the plane where the surface of the substrate is located and the tangent of the surface of the substrate, and the anti-blaze angle of the blazed grating is determined according to the incident angle and the rotation angle. In this way, by utilizing the incident angle and the rotation angle, the shielding effect of the mask can be reduced, thereby achieving the purpose of controlling the angle of the anti-blaze angle, realizing the controllability of the anti-blaze angle, thereby increasing the angle of the anti-blaze angle by controlling the incident angle and the rotation angle, and ultimately improving the diffraction efficiency of the blazed grating.

[0111] The above is only a preferred implementation of the present application. Although the present application has been disclosed as a preferred embodiment, it is not intended to limit the present application. Any technician familiar with the art can use the above disclosed methods and technical contents to make many possible changes and modifications to the technical solution of the present application without departing from the scope of the technical solution of the present application, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application still falls within the scope of protection of the technical solution of the present application.

Claims

1. A method for manufacturing a blazed grating, characterized in that: The method comprises: Providing a substrate, wherein the substrate is covered with periodically arranged masks; By utilizing the incident angle and the rotation angle, the mask is used as a mask and the substrate is etched using an ion beam to form a blazed grating; the incident angle is the angle between a first projection of the ion beam on a plane where the normal of the substrate is located and the normal of the substrate, and the rotation angle is the angle between a second projection of the ion beam on a plane where the surface of the substrate is located and a tangent to the surface of the substrate, and the anti-blazed angle of the blazed grating is determined based on the incident angle and the rotation angle.

2. The manufacturing method according to claim 1, characterized in that: The periodically arranged mask includes a mask period, a mask line width and a mask height; the blazed grating includes a blaze angle, a reverse blaze angle and a grating height; The reverse blaze angle of the blazed grating is determined according to the incident angle and the rotation angle, comprising: Among them, α is the rotation angle, β is the blaze angle, γ is the anti-blaze angle, θ is the incident angle, a is the mask period, b is the mask line width, and h is the mask height.

3. The manufacturing method according to claim 2, characterized in that:

4. The manufacturing method according to claim 2, characterized in that: The ratio of the mask etching rate to the substrate etching rate is k; 5. The manufacturing method according to claim 2, characterized in that: Wherein, h1 is the grating height.

6. The manufacturing method according to claim 2, characterized in that: The direction of the acute angle formed by the ion beam and the plane where the surface of the substrate is located is the same as the direction of the blaze angle.

7. The manufacturing method according to claim 4, characterized in that: The range of the mask period is [200 nanometers, 10 micrometers], the range of the mask line width is [5%, 80%] of the mask period, and the mask height is greater than or equal to the product of the grating height and k.

8. The manufacturing method according to claim 1, characterized in that: The rotation angle is not 0.

9. The manufacturing method according to claim 8, characterized in that: The rotation angle has an angle range of [-90°, 90°].

10. The manufacturing method according to claim 1, characterized in that: The material of the mask is the same as that of the substrate.

11. The manufacturing method according to claim 10, characterized in that: The material of the substrate may be one or more of Al2O3, Ga2O3, Ta2O3, Si, SiO2, Si3N4, quartz and TiO2.

12. The manufacturing method according to claim 2, characterized in that: When the rotation angle is determined, the positive or negative value of the incident angle affects the direction of the blaze angle, but does not affect the size of the blaze angle, the size of the anti-blaze angle, and the size of the grating height.

13. The manufacturing method according to claim 2, characterized in that: When the incident angle is determined, the positive or negative value of the rotation angle does not affect the direction of the blaze angle, the size of the blaze angle, the size of the anti-blaze angle, and the size of the grating height.

14. The manufacturing method according to claim 1, characterized in that: When the rotation angle is 0, the lateral etching rate of the substrate is greater than the lateral etching rate of the substrate when the rotation angle is not 0.

15. The manufacturing method according to claim 1, characterized in that: The method further comprises: A first etching gas is introduced into the discharge chamber, and a second etching gas is introduced into the etching chamber. The substrate is located in the etching chamber, and the first etching gas is used to form plasma.

16. The manufacturing method according to claim 1, characterized in that: The first etching gas includes one or more of an inert gas, a fluorine-based gas, a chlorine-based gas, a bromine-based gas, nitrogen or oxygen, and the second etching gas includes one or more of a fluorine-based gas, a chlorine-based gas, a bromine-based gas or oxygen.

17. The manufacturing method according to claim 16, characterized in that: The gas flow rate range of the first etching gas is [10 sccm, 200 sccm], and the gas flow rate range of the second etching gas is [50 sccm, 5000 sccm].

18. The manufacturing method according to claim 16, characterized in that: The beam energy range is [50V, 600V].

19. The manufacturing method according to claim 18, characterized in that: The accelerating voltage was 20% of the beam energy.

20. The manufacturing method according to claim 1, characterized in that: The beam current range is [50mA, 1200mA].

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