Blazed grating and etching method thereof

Abstract

The invention provides a blazed grating and an etching method thereof, and the method comprises the steps: forming a plurality of homogeneous mask units which are arranged at intervals in a first direction on a first surface of a to-be-etched film layer, an ion beam used for etching is incident to the to-be-etched film layer with the homogeneous mask units from one side of the first surface at an incident angle alpha, a plurality of blazed grating units which are sequentially arranged in the first direction are formed, and each blazed grating unit comprises a blazed grating main body part and a blazed grating discontinuous part; the width of the discontinuous part of the blazed grating is calculated by s-(h * tan alpha), and the incident angle alpha of the ion beam, the thickness h of the homogeneous mask units and the distance s between any two adjacent homogeneous mask units are changed, so that the width of the discontinuous part of the blazed grating is controlled, and the structure of the blazed grating unit is changed; the blazed grating unit meeting specific parameter requirements can be obtained to achieve ideal diffraction efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of gratings, and more specifically, to a blazed grating and an etching method thereof. Background Art

[0002] A grating is an optical element that disperses light using the principle of multi-slit diffraction, and can also be called a diffraction grating. Through a grating, different special effects can be achieved on a special film, showing a vivid three-dimensional world, smooth animation clips like a movie, and incredible transformation effects on a plane; Augmented Reality (AR) and Virtual Reality (VR) are technology fields that have received wide attention in recent years. Their near-eye display systems form virtual images in the distance by means of a series of optical imaging elements for the pixels on the display and project them into the human eye; the difference between Augmented Reality (AR) and Virtual Reality (VR) is that AR glasses need to see both the real external world and virtual information. Therefore, the imaging system cannot block the line of sight, which requires adding one or a group of optical combiners to integrate virtual information and the real scene in a stacked form, complementing and enhancing each other.

[0003] The optical waveguide technology is a relatively characteristic optical technology born in response to the needs of AR glasses. Due to its thin and light weight and high penetration characteristics for external light, it is considered to be the necessary optical solution for consumer-grade AR glasses. Among them, the blazed grating in the Surface Relief Grating can concentrate most of the diffracted light on a single non-zero order spectrum, showing outstanding performance in light energy utilization efficiency, thus meeting the application requirements.

[0004] In addition to having a high diffraction efficiency, the blazed grating can also significantly improve the sensitivity, resolution, and measurement range of the grating measurement system. Therefore, it is also a core functional component for improving ultra-precision manufacturing; although many qualitative and quantitative studies have been carried out on the development of high-diffraction-efficiency blazed gratings, however, with the increase in application scenarios, since the use conditions of the blazed grating are fixed and the ideal diffraction efficiency cannot be achieved, therefore, how to obtain a blazed grating that can meet specific parameter requirements is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0005] In view of this, to solve the above problems, the present invention provides a blazed grating and an etching method thereof, which can obtain a blazed grating that meets specific parameter requirements. The technical solution is as follows:

[0006] The present application provides an etching method for a blazed grating. The etching method for the blazed grating includes:

[0007] Providing a film layer to be etched;

[0008] Treat the first surface of the film layer to be etched to form a plurality of homogeneous mask units arranged at intervals in a first direction, the first direction being parallel to the plane of the film layer to be etched, the thickness of the homogeneous mask unit in a second direction being h, the second direction being perpendicular to the plane of the film layer to be etched, and the distance between any two adjacent homogeneous mask units being s;

[0009] Incident an ion beam for etching from one side of the first surface onto the film layer to be etched having the homogeneous mask units at an incident angle α to form a plurality of blazed grating units arranged in sequence in the first direction, the blazed grating unit including a blazed grating main part and a blazed grating discontinuous part, and the blazed grating main part and the blazed grating discontinuous part being arranged in sequence in the first direction;

[0010] Wherein, the incident angle α is the angle between the normal line of the plane of the film layer to be etched and the incident direction of the ion beam, 0° < α < arctan(s / h), and the value of the width of the blazed grating discontinuous part in the first direction is s - (h × tanα).

[0011] Preferably, in the above method for etching a blazed grating, the treating the first surface of the film layer to be etched to form a plurality of homogeneous mask units arranged at intervals in a first direction includes:

[0012] Form an initial film layer on the first surface of the film layer to be etched, the initial film layer having a plurality of grooves that penetrate the initial film layer in the second direction, exposing a part of the first surface of the film layer to be etched, so that the initial film layer forms a plurality of independent initial film layer units arranged at intervals in the first direction;

[0013] Place the film layer to be etched having the initial film layer units in a first etching chamber for treatment, so that the film layer to be etched forms a plurality of the homogeneous mask units arranged at intervals in the first direction.

[0014] Preferably, in the above method for etching a blazed grating, the incident an ion beam for etching from one side of the first surface onto the film layer to be etched having the homogeneous mask units at an incident angle α to form a plurality of blazed grating units arranged in sequence in the first direction includes:

[0015] Place the film layer to be etched having the homogeneous mask units on the sample stage of a second etching chamber, and incident the ion beam from one side of the first surface onto the film layer to be etched having the homogeneous mask units at the incident angle α;

[0016] Adjust the rotation angle β of the sample stage, and process the layer to be etched with the homogeneous mask unit to form a plurality of the blazed grating units arranged in sequence in the first direction. The inclination angle of the discontinuous part of the blazed grating takes a value of arctan(tanα × cosβ).

[0017] Preferably, in the above-described method for etching a blazed grating, the rotation angle β takes a value in the range of 0° - 80°.

[0018] Preferably, in the above-described method for etching a blazed grating, the width of the initial film layer unit in the first direction takes a value in the range of 20 nm - 12 μm;

[0019] Define the distance between any two adjacent initial film layer units and the width of one of the initial film layer units in the first direction as an initial period, and the initial period takes a value in the range of 100 nm - 15 μm.

[0020] Preferably, in the above-described method for etching a blazed grating, the thickness h of the homogeneous mask unit in the second direction takes a value in the range of 200 nm - 50 μm;

[0021] The ratio of the width of the homogeneous mask unit in the first direction to the width of the initial film layer unit in the first direction takes a value in the range of 30% - 100%;

[0022] The distance s between any two adjacent homogeneous mask units takes a value of the difference between the initial period and the width of the homogeneous mask unit in the first direction.

[0023] Preferably, in the above-described method for etching a blazed grating, when forming the blazed grating unit in the second etching chamber, the process parameters of the ion beam include:

[0024] The beam energy of the ion beam takes a value in the range of 100 V - 1000 V, the ratio of the acceleration voltage of the ion beam to the beam energy of the ion beam is 20%, and the beam current of the ion beam takes a value in the range of 50 mA - 1200 mA.

[0025] Preferably, in the above-described method for etching a blazed grating, the first etching gas introduced into the first etching chamber is one etching gas or a mixed gas of a plurality of etching gases selected from Ar, O2, CHF3, CF4, C4F8, SF6, Cl2.

[0026] Preferably, in the above-described method for etching a blazed grating, the second etching gas introduced into the second etching chamber is one etching gas or a mixed gas of a plurality of etching gases selected from Ar, O2, CHF3, CF4, C4F8, SF6, Cl2.

[0027] The present application also provides a blazed grating, and the blazed grating is prepared based on the etching method of the above-mentioned blazed grating.

[0028] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0029] A blazed grating and an etching method thereof provided by the present invention, the etching method of the blazed grating includes: providing a film layer to be etched; processing the first surface of the film layer to be etched to form a plurality of homogeneous mask units arranged at intervals in a first direction, the first direction being parallel to the plane where the film layer to be etched is located, the thickness of the homogeneous mask unit in a second direction being h, the second direction being perpendicular to the plane where the film layer to be etched is located, and the distance between any two adjacent homogeneous mask units being s; incident an ion beam for etching from one side of the first surface onto the film layer to be etched having the homogeneous mask units, so as to form a plurality of blazed grating units arranged in sequence in the first direction, the blazed grating unit including a blazed grating main body part and a blazed grating discontinuous part, and the blazed grating main body part and the blazed grating discontinuous part being arranged in sequence in the first direction; since the width of the blazed grating discontinuous part in the first direction in the present invention is calculated by s-(h×tanα), the width of the blazed grating discontinuous part depends on the incident angle α of the ion beam, the thickness h of the homogeneous mask unit in the second direction, and the distance s between any two adjacent homogeneous mask units, by changing the incident angle α of the ion beam, the thickness h of the homogeneous mask unit in the second direction, and the distance s between any two adjacent homogeneous mask units, thereby realizing the control of the width of the blazed grating discontinuous part, so as to change the structure of the blazed grating unit, and a blazed grating unit meeting specific parameter requirements can be obtained to achieve an ideal diffraction efficiency. Description of the Drawings

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention, and for those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0031] Figure 1 It is a schematic flow chart of an etching method of a blazed grating provided by an embodiment of the present invention;

[0032] Figure 2 It is a schematic flow chart of forming a blazed grating by using a film layer to be etched provided by an embodiment of the present invention;

[0033] Figure 3Schematic diagram of a multi - perspective structure of an etch - target film layer with a homogeneous mask unit provided by an embodiment of the present invention;

[0034] Figure 4 Schematic diagram of a structure of a blazed grating unit provided by an embodiment of the present invention;

[0035] Figure 5 Flow - chart schematic diagram of another method for etching a blazed grating provided by an embodiment of the present invention;

[0036] Figure 6 Flow - chart schematic diagram of another process for forming a blazed grating using an etch - target film layer provided by an embodiment of the present invention;

[0037] Figure 7 Flow - chart schematic diagram of yet another method for etching a blazed grating provided by an embodiment of the present invention;

[0038] Figure 8 Schematic diagram of another structure of a blazed grating unit provided by an embodiment of the present invention. Detailed implementation manners

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0040] Based on the content recorded in the background technology, the inventors found during the inventive process of the present invention that with the increase in application scenarios, since the usage conditions of the blazed grating are fixed and the ideal diffraction efficiency cannot be achieved, therefore, how to obtain a blazed grating that can meet specific parameter requirements is a technical problem that those skilled in the art urgently need to solve.

[0041] Based on this, the present application provides a blazed grating and an etching method thereof, which can obtain a blazed grating that meets specific parameter requirements.

[0042] To make the above - mentioned objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0043] An embodiment of the present invention provides a... Refer to Figure 1 , Figure 1 Flow - chart schematic diagram of a method for etching a blazed grating provided by an embodiment of the present invention. In combination with Figure 1 , the method for etching the blazed grating includes:

[0044] S100: Provide an etch - target film layer.

[0045] Specifically, in this step S100, the material of the film layer to be etched includes but is not limited to Si material, SiO2 material, quartz material, high-refractive-index glass material, etc. The refractive index of the high-refractive-index glass material is greater than 2.

[0046] S200: Treat the first surface of the film layer to be etched to form a plurality of homogeneous mask units arranged at intervals in a first direction. The first direction is parallel to the plane where the film layer to be etched is located. The thickness of the homogeneous mask unit in a second direction is h, and the second direction is perpendicular to the plane where the film layer to be etched is located. The distance between any two adjacent homogeneous mask units is s.

[0047] Specifically, in this step S200, as Figure 2 shown, Figure 2 is a schematic flow chart of forming a blazed grating by using a film layer to be etched provided by an embodiment of the present invention. Figure 2 In the process from a to b, the first surface 11 of the film layer to be etched 1 needs to be treated to form a plurality of homogeneous mask units 2 arranged at intervals in a first direction A, and the formed homogeneous mask units 2; as Figure 3 shown, Figure 3 is a multi-view structure schematic diagram of a film layer to be etched with homogeneous mask units provided by an embodiment of the present invention. Figure 3 In d is a schematic diagram of the film layer to be etched 1 with homogeneous mask units 2. Figure 3 In e is a front view of the projection of the film layer to be etched 1 with homogeneous mask units 2 in a third direction C. Figure 3 In f is a top view of the projection of the film layer to be etched 1 with homogeneous mask units 2 in a second direction B; due to the large difference in the etching rate between the heterogeneous mask and the film layer to be etched 1, the rate of the heterogeneous mask is often lower than that of the film layer to be etched 1. It is necessary to completely consume the heterogeneous mask before the triangular apex of the blazed grating can be formed. Therefore, the etching time is long, and it is very difficult to make the triangular apex of the blazed grating very sharp, which affects the photoelectric conversion efficiency. At the same time, due to the long etching time of the heterogeneous mask, it is very difficult to make the blaze angle and the anti-blaze angle of the blazed grating large, and the height of the blazed grating is not high; while the etching rate of the homogeneous mask unit 2 is basically the same as that of the film layer to be etched 1, which is more conducive to forming a blazed grating, and the triangular apex of the formed blazed grating is sharper.

[0048] S300: Incident the ion beam for etching from one side of the first surface 11 to the film layer 1 to be etched with the homogeneous mask unit 2 at an incident angle α, so as to form a plurality of blazed grating units 3 arranged in sequence in the first direction A. The blazed grating unit 3 includes a blazed grating main part and a blazed grating discontinuous part, and the blazed grating main part and the blazed grating discontinuous part are arranged in sequence in the first direction A; wherein, the incident angle α is the included angle between the normal line of the plane where the film layer 1 to be etched is located and the incident direction of the ion beam, 0° < α < arctan(s / h), and the value of the width of the blazed grating discontinuous part in the first direction A is s - (h×tanα).

[0049] Specifically, in this step S300, in combination with Figures 2 - 4 for illustration, Figure 2 the process from b to c in is to process the film layer 1 to be etched with the homogeneous mask unit 2 to form a plurality of blazed grating units 3 arranged in sequence in the first direction A. Figure 4 is a schematic structural diagram of a blazed grating unit provided by an embodiment of the present invention. As shown in Figure 3 e in, in the embodiment of the present invention, the film layer 1 with two homogeneous mask units 2 is used for illustration. The two homogeneous mask units 2 are respectively a first homogeneous mask unit 21 and a second homogeneous mask unit 22 arranged at intervals in the first direction A. Since the value range of the incident angle α of the ion beam is 0° < α < arctan(s / h), when the ion beam is incident at the incident angle α as shown in Figure 3 e in, there are intersections on the surfaces of the distances between the ion beam and the two homogeneous mask units 2, and there are certain distances between the intersections and the two homogeneous mask units 2; during etching, the plane between the intersection and the first homogeneous mask unit 21 will be preferentially etched. Since there is no second homogeneous mask unit 22 to block when the ion beam is incident on this plane, this plane will finally form the blazed grating discontinuous part 32, and the width w2 of the blazed grating discontinuous part 32 is calculated by s - (h×tanα); as the thickness h of the two homogeneous mask units 2 gradually decreases in the second direction B, the plane between the intersection and the second homogeneous mask unit 22 will be gradually etched, so as to form the blazed grating main part 31; it should be noted that the embodiment of the present invention stipulates the range of the incident angle α. When the incident angle α is not within the range of 0° < α < arctan(s / h), the blazed grating discontinuous part cannot be formed; the quantization of the width of the blazed grating discontinuous part in the first direction A is to facilitate the user to calculate the width of the blazed grating discontinuous part according to the formula s - (h×tanα), or to adjust the incident angle α and the height of the homogeneous mask unit 2 according to the required width of the blazed grating discontinuous part.

[0050] As can be seen from the above description, an etched blazed grating and an etching method thereof provided by an embodiment of the present invention. The etching method of the blazed grating includes: providing an etched film layer 1; processing a first surface 11 of the etched film layer 1 to form a plurality of homogeneous mask units 2 arranged at intervals in a first direction A, the first direction A being parallel to the plane where the etched film layer 1 is located, the thickness of the homogeneous mask unit 2 in a second direction B being h, the second direction B being perpendicular to the plane where the etched film layer 1 is located, and the distance between any two adjacent homogeneous mask units 2 being s; incident an ion beam for etching from one side of the first surface 11 onto the etched film layer 1 having the homogeneous mask units 2 at an incident angle α to form a plurality of blazed grating units 3 arranged in sequence in the first direction A. The blazed grating unit 3 includes a blazed grating main body part 31 and a blazed grating discontinuous part 32, and the blazed grating main body part 31 and the blazed grating discontinuous part 32 are arranged in sequence in the first direction A; since the width w2 of the blazed grating discontinuous part 32 in the first direction A in the present invention is calculated by s-(h×tanα), the width w2 of the blazed grating discontinuous part 32 depends on the incident angle α of the ion beam, the thickness h of the homogeneous mask unit 2 in the second direction B, and the distance s between any two adjacent homogeneous mask units 2. By changing the incident angle α of the ion beam, the thickness h of the homogeneous mask unit 2 in the second direction B, and the distance s between any two adjacent homogeneous mask units 2, the width w2 of the blazed grating discontinuous part 32 can be controlled, so as to change the structure of the blazed grating unit 3, and a blazed grating unit 3 that meets specific parameter requirements can be obtained to achieve an ideal diffraction efficiency.

[0051] Optionally, in another embodiment of the present invention, step S200 in the above etching method of a blazed grating: processing the first surface 11 of the etched film layer 1 to form a plurality of homogeneous mask units 2 arranged at intervals in the first direction A is further described with reference to Figure 5 , Figure 5 is a schematic flow chart of another etching method of a blazed grating provided by an embodiment of the present invention. As shown in Figure 5 The processing of the first surface 11 of the etched film layer 1 to form a plurality of homogeneous mask units 2 arranged at intervals in the first direction A includes:

[0052] S201: forming an initial film layer on the first surface 11 of the etched film layer 1, the initial film layer having a plurality of grooves that penetrate the initial film layer in the second direction B, exposing a part of the first surface 11 of the etched film layer 1, so that the initial film layer forms a plurality of independent initial film layer units arranged at intervals in the first direction A.

[0053] Specifically, in this step S201, as Figure 6 shown, Figure 6 is a schematic flow chart of another method for forming a blazed grating using an etching target film layer provided by an embodiment of the present invention. Figure 6 The process of forming Figure g from Figure a includes but is not limited to first forming an initial film layer on the first surface 11 of the etching target film layer 1, and then etching the initial film layer to form a plurality of grooves exposing part of the first surface 11 of the etching target film layer 1. The remaining unetched initial film layer is the initial film layer unit 4. The material of the initial film layer includes but is not limited to one of photoresist material, Cr material, Mo material, Al material, Al2O3 material, TiN material, etc. The value range of the width w3 of the initial film layer unit 4 in the first direction A is 20 nm - 12 μm. And the distance between any two adjacent initial film layer units 4 and the width w3 of one of the initial film layer units 4 in the first direction A are defined as an initial period p, and the value range of the initial period p is 100 nm - 15 μm. The first etching chamber includes but is not limited to one of a capacitively coupled plasma (CCP) chamber, an inductively coupled plasma (ICP) chamber, a reactive ion beam etching (RIBE) chamber, etc.

[0054] S202: Place the etching target film layer 1 with the initial film layer unit 4 in a first etching chamber for processing, so that the etching target film layer 1 forms a plurality of homogeneous mask units 2 arranged at intervals in the first direction A.

[0055] Specifically, in this step S202, as Figure 6 shown, in Figure 6In the process of forming figure b from figure g, the to-be-etched film layer 1 with the initial film layer unit 4 is placed in the first etching chamber, and then the to-be-etched film layer 1 is etched using the initial film layer unit 4 as a mask to form a plurality of homogeneous mask units 2 arranged at intervals in the first direction A; wherein, the first etching gas introduced into the first etching chamber includes but is not limited to one etching gas or a mixed gas of multiple etching gases among Ar, O2, CHF3, CF4, C4F8, SF6, and Cl2; the value range of the thickness h of the homogeneous mask unit 2 in the second direction B is 200 nm - 50 μm, and the value range of the ratio of the width w1 of the homogeneous mask unit 2 in the first direction A to the width w3 of the initial film layer unit 4 in the first direction A is 30% - 100%; the value of the distance s between any two adjacent homogeneous mask units 2 is the difference between the initial period p and the width w1 of the homogeneous mask unit 2 in the first direction A.

[0056] Optionally, in another embodiment of the present invention, step S300 in the above etching method of a blazed grating: The ion beam for etching is incident on the to-be-etched film layer 1 with the homogeneous mask unit 2 from one side of the first surface 11 at an incident angle α to form a plurality of blazed grating units 3 arranged in sequence in the first direction A. This implementation process is further described with reference to Figure 7 , Figure 7 which is a schematic flowchart of another etching method of a blazed grating provided by an embodiment of the present invention. As shown in Figure 7 , the ion beam for etching is incident on the to-be-etched film layer 1 with the homogeneous mask unit 2 from one side of the first surface 11 at an incident angle α to form a plurality of blazed grating units 3 arranged in sequence in the first direction A, including:

[0057] S301: Place the to-be-etched film layer 1 with the homogeneous mask unit 2 on the sample stage of the second etching chamber, and incident the ion beam on the to-be-etched film layer 1 with the homogeneous mask unit 2 from one side of the first surface 11 at the incident angle α.

[0058] Specifically, in this step S301, the second etching gas introduced into the second etching chamber includes, but is not limited to, one etching gas or a mixed gas of multiple etching gases among Ar, O2, CHF3, CF4, C4F8, SF6, and Cl2. When forming the blazed grating unit 3 in the second etching chamber, the process parameters of the ion beam include: the value range of the beam energy of the ion beam is 100V - 1000V, the ratio of the acceleration voltage of the ion beam to the beam energy of the ion beam is 20%, and the value range of the beam current of the ion beam is 50mA - 1200mA; the second etching chamber is a Reactive Ion Beam Etching (RIBE) chamber.

[0059] S302: Adjust the rotation angle β of the sample stage, and process the film layer 1 to be etched with the homogeneous mask unit 2 to form a plurality of blazed grating units 3 arranged in sequence in the first direction A. The inclination angle of the discontinuous part 32 of the blazed grating takes the value of arctan(tanα × cosβ).

[0060] Specifically, in this step S302, as Figure 3 shown in f, adjust the rotation angle β of the sample stage, that is, rotate the sample stage so that in the second direction B, the angle between the positive projection of the ion beam on the plane where the film layer 1 to be etched is located before rotation and the positive projection of the ion beam on the plane where the film layer 1 to be etched is located after rotation is β; the value range of the rotation angle β is 0° - 80°; since when the ion beam performs etching, the first homogeneous mask unit 21 will hinder the volatilization of the material of the film layer 1 to be etched, the etching rate of the plane between the intersection point and the first homogeneous mask unit 21 will become slower, thereby forming the inclination angle of the discontinuous part 32 of the blazed grating, as Figure 8 shown. Figure 8 This is another structural schematic diagram of the blazed grating unit provided by the embodiment of the present invention. The inclination angle θ1 is the inclination angle of the discontinuous part 32 of the blazed grating. The inclination angle θ1 is determined by the incident angle α and the rotation angle β. The θ2 angle of the blazed grating main body part 31 is the blaze angle, and the θ3 angle of the blazed grating main body part 31 is the anti - blaze angle.

[0061] Optionally, based on the above - mentioned embodiments of the present invention, several etching methods of the blazed grating are also exemplified in another embodiment of the present invention, specifically as follows:

[0062] Embodiment 1: The to-be-etched film layer 1 with the initial film layer unit 4 is placed into an inductively coupled plasma (ICP) chamber. The initial film layer unit 4 is a photoresist, and the material of the to-be-etched film layer 1 is Si material. Wherein the initial period p of the initial film layer unit 4 is 400 nm, the width w3 of the initial film layer unit 4 in the first direction A is 190 nm, and the height of the initial film layer unit 4 in the second direction B is 320 nm; SF6 gas is introduced into the inductively coupled plasma (ICP) chamber. After the SF6 gas is ionized into plasma, the to-be-etched film layer 1 is etched to form a plurality of homogeneous mask units 2 arranged at intervals in the first direction A. The period of the homogeneous mask unit 2 is 400 nm, the width w1 of the homogeneous mask unit 2 in the first direction A is 120 nm, and the thickness h of the homogeneous mask unit 2 in the second direction B is 340 nm; the residual initial film layer unit 4 on the top of the homogeneous mask unit 2 is removed; the homogeneous mask unit 2 is placed into a reactive ion beam etching (RIBE) chamber, and the incident angle α of the ion beam is adjusted to 20°, and the rotation angle β of the sample stage is 0°, that is, the sample stage is not rotated; etching gas Ar is introduced into the reactive ion beam etching (RIBE) chamber. The beam energy is set to 600 V, the acceleration voltage is 120 V, and the beam current is 500 mA. After the etching gas Ar is ionized into plasma and is neutralized and led out through the grid, the to-be-etched film layer 1 with the homogeneous mask unit 2 is etched for 250 s to form a plurality of blazed grating units 3 arranged in sequence in the first direction A. The width w2 of the blaze grating discontinuity part 32 in the first direction A is 160 nm, the inclination angle θ1 of the blaze grating discontinuity part 32 is 18°, the blaze angle θ2 of the blaze grating main body part 31 is 40°, and the anti-blaze angle θ3 of the blaze grating main body part 31 is 80°.

[0063] Example 2: Place the film layer 1 to be etched with the initial film layer unit 4 into an inductively coupled plasma (ICP) chamber. The initial film layer unit 4 is a photoresist, and the material of the film layer 1 to be etched is Si material. The initial period p of the initial film layer unit 4 is 330 nm, the width w3 of the initial film layer unit 4 in the first direction A is 190 nm, and the height of the initial film layer unit 4 in the second direction B is 320 nm. Introduce SF6 gas into the inductively coupled plasma (ICP) chamber. After the SF6 gas is ionized into plasma, it etches the film layer 1 to be etched, forming a plurality of homogeneous mask units 2 arranged at intervals in the first direction A. The period of the homogeneous mask unit 2 is 330 nm, the width w1 of the homogeneous mask unit 2 in the first direction A is 120 nm, and the thickness h of the homogeneous mask unit 2 in the second direction B is 230 nm. Remove the remaining initial film layer unit 4 on the top of the homogeneous mask unit 2. Place the homogeneous mask unit 2 into a reactive ion beam etching (RIBE) chamber, and adjust the incident angle α of the ion beam to 10° and the rotation angle β of the sample stage to 60°. Introduce the etching gas Ar into the reactive ion beam etching (RIBE) chamber, set the beam energy to 600 V, the acceleration voltage to 120 V, and the beam current to 500 mA. After the etching gas Ar is ionized into plasma and is neutralized by being led out through the grid, the film layer 1 to be etched with the homogeneous mask unit 2 is etched for 250 s, forming a plurality of blazed grating units 3 arranged in sequence in the first direction A. The width w2 of the blazed grating discontinuous part 32 in the first direction A is 160 nm, the inclination angle θ1 of the blazed grating discontinuous part 32 is 10°, the blazed angle θ2 of the blazed grating main part 31 is 50°, and the anti-blazed angle θ3 of the blazed grating main part 31 is 50°.

[0064] Optionally, based on the above embodiments of the present invention, in another embodiment of the present invention, a blazed grating is further provided. The blazed grating is prepared based on the etching method of the blazed grating described in the above embodiments.

[0065] The above has introduced in detail a blazed grating and its etching method provided by the present invention. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention. At the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

[0066] It should be noted that the embodiments in this specification are all described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple. For the relevant parts, reference can be made to the description in the method part.

[0067] It should also be noted that in this text, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements also includes the elements inherent to these processes, methods, articles or devices, or further includes the elements inherent to these processes, methods, articles or devices. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article or device including the said element.

[0068] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An etching method for a blazed grating, characterized in that, The etching method of the blazed grating includes: Providing a film layer to be etched; Processing the first surface of the film layer to be etched to form a plurality of homogeneous mask units arranged at intervals in a first direction, the first direction being parallel to the plane of the film layer to be etched, the thickness of the homogeneous mask unit in a second direction being h, the second direction being perpendicular to the plane of the film layer to be etched, and the distance between any two adjacent homogeneous mask units being s; Inciding an ion beam for etching from one side of the first surface onto the film layer to be etched having the homogeneous mask units at an incident angle α to form a plurality of blazed grating units arranged in sequence in the first direction, the blazed grating unit including a blazed grating main part and a blazed grating discontinuous part, and the blazed grating main part and the blazed grating discontinuous part being arranged in sequence in the first direction; Wherein, the incident angle α is the angle between the normal line of the plane of the film layer to be etched and the incident direction of the ion beam, 0° < α < arctan(s / h), and the value of the width of the blazed grating discontinuous part in the first direction is s - (h × tanα).

2. The etching method for a blazed grating according to claim 1, characterized in that, The processing of the first surface of the film layer to be etched to form a plurality of homogeneous mask units arranged at intervals in a first direction includes: Forming an initial film layer on the first surface of the film layer to be etched, the initial film layer having a plurality of grooves that penetrate the initial film layer in the second direction, exposing a part of the first surface of the film layer to be etched, so that the initial film layer forms a plurality of independent initial film layer units arranged at intervals in the first direction; Placing the film layer to be etched having the initial film layer units in a first etching chamber for processing, so that the film layer to be etched forms a plurality of the homogeneous mask units arranged at intervals in the first direction.

3. The etching method for a blazed grating according to claim 1, characterized in that, The inciding of the ion beam for etching from one side of the first surface onto the film layer to be etched having the homogeneous mask units at an incident angle α to form a plurality of blazed grating units arranged in sequence in the first direction includes: Placing the film layer to be etched having the homogeneous mask units on a sample stage in a second etching chamber, and inciding the ion beam from one side of the first surface onto the film layer to be etched having the homogeneous mask units at the incident angle α; Adjusting the rotation angle β of the sample stage to process the film layer to be etched having the homogeneous mask units to form a plurality of the blazed grating units arranged in sequence in the first direction, and the value of the inclination angle of the blazed grating discontinuous part is arctan(tanα × cosβ).

4. The etching method for a blazed grating according to claim 3, characterized in that, The value range of the rotation angle β is 0° - 80°; 5. The etching method for a blazed grating according to claim 2, characterized in that, The value range of the width of the initial film layer unit in the first direction is 20 nm - 12 μm; Defining the distance between any two adjacent initial film layer units and the width of one of the initial film layer units in the first direction as an initial period, and the value range of the initial period is 100 nm - 15 μm.

6. The etching method for a blazed grating according to claim 5, characterized in that, The thickness h of the homogeneous mask unit in the second direction ranges from 200 nm to 50 μm; The value range of the ratio of the width of the homogeneous mask unit in the first direction to the width of the initial film layer unit in the first direction is 30% - 100%; The spacing s between any two adjacent homogeneous mask units is the difference between the initial period and the width of the homogeneous mask unit in the first direction.

7. The etching method for a blazed grating according to claim 3, characterized in that, When forming the blazed grating unit in the second etching chamber, the process parameters of the ion beam include: The beam energy of the ion beam ranges from 100 V to 1000 V, the ratio of the acceleration voltage of the ion beam to the beam energy of the ion beam is 20%, and the beam current of the ion beam ranges from 50 mA to 1200 mA.

8. The etching method for a blazed grating according to claim 2, characterized in that, The first etching gas introduced into the first etching chamber is one etching gas or a mixed gas of multiple etching gases selected from Ar, O2, CHF3, CF4, C4F8, SF6, and Cl2.

9. The etching method for a blazed grating according to claim 3, characterized in that, The second etching gas introduced into the second etching chamber is one etching gas or a mixed gas of multiple etching gases selected from Ar, O2, CHF3, CF4, C4F8, SF6, and Cl2.

10. A blazed grating, characterized in that, The blazed grating is prepared based on the etching method of the blazed grating according to any one of claims 1 - 9.

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