Method for manufacturing microlens in groove and structure of microlens in groove

Abstract

The present invention discloses a method for manufacturing a microlens in a groove and a microlens structure in a groove. The microlens is transferred through three etching processes to realize the manufacturing of the microlens in the groove, and the depth of the groove can be accurately controlled. The error range of the groove depth is controlled within 2 μm, and it is suitable for the manufacturing of microlenses in ultra-deep grooves with a groove depth greater than or equal to 50 μm. The three etching processes include one steady-state etching and two deep silicon etchings. The steady-state etching can realize the transfer of the microlens. The first deep silicon etching adopts fast-rate etching to quickly form the groove structure contour. The second deep silicon etching adopts slow-rate etching to realize the precise control of the groove structure depth.

Description

Technical Field

[0001] The invention belongs to the technical field of microlenses, and in particular relates to a method for manufacturing a microlens in a groove and a microlens in a groove structure. Background Art

[0002] Micro lenses, especially silicon lenses, are widely used in optical communications, optical transmission, laser radar, industrial control and consumer applications. Lenses in grooves are increasingly popular in the industry because they not only protect the lens structure but also provide a support platform for subsequent packaging. However, the groove depth developed by existing processes is limited, generally within 50μm, which seriously affects the scope of use.

[0003] The existing technology generally uses a metal mask route or a bonding process route to make a lens in a groove, both of which have great disadvantages. In the metal mask route, the metal mask is difficult to make, the thickness is limited, the process is complex and the cost is high, which limits the large-scale promotion of the process and makes it difficult to make products with a groove depth of more than 50μm. In the metal bonding process route, it is mainly necessary to separately make the lens structure and the deep groove structure. The process is relatively complex and there is a reliability risk, especially in the harsh high-speed communication application field.

[0004] The existing technology in the CPO (co-packaged optics) field needs to directly rely on deep groove structure mounting alignment as a coupling focal length, requiring the deep groove tolerance to be within ±5μm, which poses a great challenge to the existing technology.

[0005] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0006] The purpose of the present invention is to provide a method for manufacturing a microlens in a groove and a microlens in a groove structure, which completes the transfer of the microlens through three etching processes, realizes the manufacturing of the microlens in the groove, and can accurately control the depth of the groove, and the error range of the control groove depth is within 2μm.

[0007] In order to achieve the above object, a technical solution provided by a specific embodiment of the present invention is as follows:

[0008] A method for manufacturing a microlens in a groove, wherein the groove has a preset depth greater than a sagittal height of the microlens, the manufacturing method comprising:

[0009] Providing a substrate, the substrate having a first surface, the first surface including a first area, a second area surrounding the first area, and a third area surrounding the second area;

[0010] forming a gumball microlens surface shape on a first area of ​​the first surface;

[0011] Performing a first etching on the surface shape of the glue ball microlens and the first surface, replicating and transferring the surface shape of the glue ball microlens to the substrate to form a microlens;

[0012] forming a protective layer on a surface of the substrate on which the microlens is formed;

[0013] removing the protective layers in the first and second regions to expose the microlenses and the substrate;

[0014] Performing a second etching on the microlens in the first region and the substrate in the second region at a first etching rate to form a microlens in the groove, wherein the depth of the second etching is less than the preset depth;

[0015] The microlenses in the first region and the substrate in the second region are continuously etched for a third time at a second etching rate so that the depth of the grooves in the microlenses in the grooves reaches the preset depth, and the second etching rate is less than the first etching rate.

[0016] In one or more embodiments of the present invention,

[0017] The first etching rate range is 10 μm / min-20 μm / min, and the pressure is 15 mTorr-40 mTorr;

[0018] The second etching rate ranges from 1 μm / min to 2 μm / min, and the pressure ranges from 15 mTorr to 40 mTorr.

[0019] In one or more embodiments of the present invention, the second etching and the third etching both adopt deep silicon etching method.

[0020] In one or more embodiments of the present invention, during the second etching process, the passivation gas includes C 4 F 8 , gas flow range is 500sccm-100sccm, upper electrode power is 1500W-2500W, lower electrode power is 0, passivation time is 1s-3s; etching gas includes SF 6 , gas flow range is 500sccm-100sccm, upper electrode power is 1500W-2500W, lower electrode power is 20W-100W, and time is 1s-3s.

[0021] In one or more embodiments of the present invention, during the third etching process, the passivation gas includes C 4 F 8 , gas flow range is 100sccm-200sccm, upper electrode power is 800W-1500W, lower electrode power is 0, passivation time is 1s-3s; etching gas includes SF6 , gas flow range is 80sccm-150sccm, upper electrode power is 800W-1200W, lower electrode power is 20W-100W, and time is 1s-3s.

[0022] In one or more embodiments of the present invention, the first etching adopts a steady-state etching method; and / or,

[0023] The etching gas for the first etching is a fluorine-based gas, and the fluorine-based gas includes SF 6 CF 4 , CHF 3 、C4F 8 One or more of; and / or,

[0024] The etching gas flow rate of the first etching is in the range of 20 sccm-40 sccm; and / or,

[0025] The etching power of the first etching is 600W-1000W, the radio frequency power is 300W-500W, and the pressure is 3mTorr-10mTorr.

[0026] In one or more embodiments of the present invention, the material of the protective layer includes silicon oxide; and / or,

[0027] The protective layer is formed by plasma enhanced chemical vapor deposition, wherein the deposition temperature is 300°C-350°C, the power is 50W-80W, the pressure is 100Pa-120Pa, and the reaction gas includes SiH 4 and N 2 O; and / or,

[0028] The deposition thickness of the protective layer is 500nm-1000nm; and / or

[0029] The etching selection ratio of the protective layer to the substrate is (1:50)-(1:200).

[0030] In one or more embodiments of the present invention, removing the protective layer of the first region and the second region to expose the microlens and the substrate includes:

[0031] forming a photoresist layer on the surface of the protective layer;

[0032] Etching the photoresist layer in the first region and the second region to expose the protective layer in the first region and the second region;

[0033] The protective layers in the first region and the second region are etched by a steady-state etching method to expose the microlens and the substrate.

[0034] In one or more embodiments of the present invention, when etching the protective layer, the etching gas is a fluorine-based gas, and the fluorine-based gas includes SF 6 CF 4 , CHF 3 、C4F 8 One or more of the following; the etching gas flow rate range is 20sccm-40sccm; the etching power is 600W-1000W, the RF power is 300W-500W, and the pressure is 3mTorr-10mTorr.

[0035] In one or more embodiments of the present invention, before the step of performing a second etching on the microlenses in the first region and the substrate in the second region, the step further includes:

[0036] The step of removing the photoresist layer in the third area.

[0037] A micro-lens in a groove structure is manufactured by adopting the manufacturing method of the micro-lens in a groove.

[0038] Compared with the prior art, the method for manufacturing a microlens in a groove and the microlens in a groove structure of the present invention complete the transfer of the microlens through three etching processes, realize the manufacturing of the microlens in the groove, and can accurately control the depth of the groove, and control the groove depth error range within 2μm, which is suitable for the manufacturing of microlenses in ultra-deep grooves with a groove depth greater than or equal to 50μm.

[0039] In the method for manufacturing a microlens in a groove and the microlens in a groove structure of the present invention, the microlens or microlens array is located in the groove, and the groove wall not only plays a supporting and protective role to prevent the microlens from being dirty and scratched, but the depth of the groove can be used for the precise positioning of the subsequent optical chip.

[0040] The method for manufacturing a microlens in a groove and the microlens structure in a groove of the present invention, the three etching processes include one steady-state etching and two deep silicon etchings, the steady-state etching can realize the transfer of the microlens, the first deep silicon etching adopts fast-rate etching to form the groove structure contour, and the second deep silicon etching adopts slow-rate etching to realize the precise control of the groove structure depth.

[0041] The method for manufacturing the microlens in a groove and the microlens in a groove structure of the present invention form a protective layer after the first etching, which can provide an etching barrier layer for subsequent process etching. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0043] Figure 1 is a process flow chart of a method for manufacturing a microlens in a groove in one embodiment of the present invention;

[0044] Figure 2 FIG. 1 is a process step diagram of a method for manufacturing a microlens in a groove according to an embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0046] As mentioned in the background technology, in the prior art, the microlens in the groove is manufactured through a metal mask route or a bonding process route. However, both of them have high process complexity and are not suitable for manufacturing a microlens in the groove structure with a depth of more than 50μm and an error of less than 5μm, and cannot be adapted to the existing CPO (co-packaged optics) technology.

[0047] Based on this, the present invention provides a method for manufacturing a microlens in a groove and a microlens structure in a groove. The microlens is transferred through three etching processes to realize the manufacturing of the microlens in the groove, and the depth of the groove can be accurately controlled. The error range of the groove depth is controlled within 2μm, which is suitable for the manufacturing of microlenses in ultra-deep grooves with a groove depth greater than or equal to 50μm. Among them, the three etching processes include one steady-state etching and two deep silicon etchings. The steady-state etching can realize the transfer of the microlens. The first deep silicon etching uses fast-rate etching to quickly form the groove structure contour. The second deep silicon etching uses slow-rate etching to achieve precise control of the groove structure depth.

[0048] like Figure 1 As shown, a method for manufacturing a microlens in a groove in an embodiment of the present invention is used to manufacture a microlens in a groove with a groove depth error within 5 μm, wherein the groove has a preset depth greater than the microlens sagittal height, and the preset depth is greater than or equal to 50 μm.

[0049] The preparation method comprises the following steps:

[0050] S1, providing a substrate having a first surface, the first surface including a first region, a second region surrounding the first region, and a third region surrounding the second region.

[0051] The substrate material is preferably silicon. On the first surface of the substrate, the first region, the second region and the third region are arranged in concentric rings or quasi-concentric rings.

[0052] S2, forming a glue ball microlens surface shape on a first area of ​​the first surface.

[0053] The conventional hot-melt reflow process is used to produce the surface shape of the glue ball microlens on the first area of ​​the first surface, wherein the conventional hot-melt reflow process involves the steps of glue spreading, photolithography, development, and reflow.

[0054] Exemplarily, a photoresist is coated on the first surface of the substrate to form a photoresist layer with uniform thickness on the first surface of the substrate. Before coating, the natural oxide layer or impurity layer on the first surface of the substrate should be removed, and the natural oxide layer on the surface of the substrate should be removed cleanly with a buffered oxide etchant (BOE). The photoresist layer is exposed and developed to form one or more columnar glue column structures on the photoresist layer. The substrate is heated to make each glue column structure reflux to form a glue ball microlens surface shape.

[0055] S3, performing a first etching on the surface of the glue ball microlens and the first surface, replicating and transferring the surface of the glue ball microlens to the substrate to form a microlens.

[0056] The ICP (inductively coupled plasma etching) plasma etching equipment is used to perform the first etching of the surface of the glue ball microlens by a steady-state etching method, so as to realize the transfer and replication of the surface of the glue ball microlens to the substrate. It can be understood that while etching the surface of the glue ball microlens, the first surface of the substrate is also synchronously etched, including the second area and the third area, and the etching selectivity ratio of the substrate to the glue ball is 1:1.

[0057] Steady-state etching in ICP etching means that the etching rate and etching depth remain relatively stable during the etching process. Steady-state etching can better control the transfer of the surface shape of the colloid ball microlens. In ICP etching, the realization of steady-state etching depends on the precise control and optimization of a series of key parameters.

[0058] In this embodiment, the etching gas for steady-state etching is a fluorine-based gas, including SF 6 CF 4 , CHF 3 , C 4 F 8 One or more of the following; the etching gas flow rate range of steady-state etching is 20sccm-40sccm; the etching power of steady-state etching is 600W-1000W, the RF power is 300W-500W, and the pressure is 3mTorr-10mTorr.

[0059] S4, forming a protective layer on the surface of the substrate on which the microlens is formed.

[0060] Preferably, the material of the protective layer is selected from silicon oxide. The protective layer is formed by plasma enhanced chemical vapor deposition (PECVD), wherein the deposition temperature is 300°C-350°C, the power is 50W-80W, the pressure is 100Pa-120Pa, and the reaction gas is SiH 4 and N 2 O, deposition thickness is 500nm-1000nm.

[0061] The protection layer completely covers the surface of the microlens and the second area and the third area.

[0062] S5, removing the protective layer in the first area and the second area to expose the microlens and the substrate.

[0063] In this step, after photolithography patterning and opening windows, the protective layer in the first area and the second area is etched. The etching parameters are consistent with the first etching-steady-state etching.

[0064] Exemplarily, a photoresist layer is formed on the surface of the protective layer; the photoresist layer in the first area and the second area is etched (the photoresist mask is patterned to open windows) to expose the protective layer in the first area and the second area; the protective layer in the first area and the second area is etched using a steady-state etching method to expose the microlens and the substrate.

[0065] Among them, the etching gas is a fluorine-based gas, including SF 6 CF 4 , CHF 3 , C 4 F 8 One or more of the following; the etching gas flow rate range is 20sccm-40sccm; the etching power is 600W-1000W, the RF power is 300W-500W, and the pressure is 3mTorr-10mTorr.

[0066] S6, performing a second etching on the microlens in the first region and the substrate in the second region at a first etching rate to form a microlens in the groove, wherein the depth of the second etching is less than a preset depth.

[0067] After the protective layers in the first and second regions are completely etched away, a fast rate deep silicon etching method is used to perform a second etching of the microlens in the first region and the substrate in the second region at a first etching rate, wherein the first etching rate ranges from 10 μm / min to 20 μm / min and the pressure is 15 mTorr to 40 mTorr.

[0068] During the second etching process, the passivation gas includes C 4 F 8, gas flow range is 500sccm-100sccm, upper electrode power is 1500W-2500W, lower electrode power is 0, passivation time is 1s-3s. Etching gas includes SF 6 , gas flow range is 500sccm-100sccm, upper electrode power is 1500W-2500W, lower electrode power is 20W-100W, and time is 1s-3s.

[0069] Since the etching rate of the second etching is relatively fast and the purpose of the second etching is to quickly form the contour of the microlens in the groove, the depth of the second etching needs to be less than the preset depth of the groove in the microlens in the groove. Preferably, the depth of the second etching is about 10 μm less than the preset depth to prevent the etching depth from exceeding the preset depth due to excessive etching rate and unstable factors of equipment process.

[0070] This deep silicon etching process can control the verticality of the groove better. Because the water drop angle of the microlens is generally in the range of 15°-20°, in the deep silicon etching step, the gas C 4 F 8 The polymer produced by passivation on the surface of the microlens can be completely removed in the etching step, so deep silicon etching can completely transfer the morphology of the microlens to the groove structure.

[0071] S7, continuing to perform a third etching on the microlens in the first area and the substrate in the second area at a second etching rate, so that the depth of the groove in the microlens in the groove reaches a preset depth, and the second etching rate is less than the first etching rate.

[0072] Before this step, the third region of the substrate needs to be treated to remove the photoresist layer. The remaining photoresist layer in the third region can be removed by heating the NMP solution at 80°.

[0073] Then, by testing the groove depth, the microlens in the first area and the substrate in the second area are etched for the third time at the second etching rate until the depth of the groove in the microlens in the groove reaches the preset depth. This etching also uses the deep silicon etching method, but this deep silicon etching is slow-rate etching. The second etching rate range is 1μm / min-2μm / min, and the pressure is 15mTorr-40mTorr. Slow-rate etching can accurately control the depth of the groove, and the depth tolerance is within ±2μm.

[0074] During the third etching process, the passivation gas includes C 4 F 8 , gas flow range is 100sccm-200sccm, upper electrode power is 800W-1500W, lower electrode power is 0, passivation time is 1s-3s; etching gas includes SF 6, gas flow range is 80sccm-150sccm, upper electrode power is 800W-1200W, lower electrode power is 20W-100W, and time is 1s-3s.

[0075] In order to prevent the second etching and the third etching from affecting the substrate in the third region, the etching selectivity ratio of the protection layer to the substrate is within (1:50)-(1:200). The thickness of the protection layer can support the depth of the third etching.

[0076] Finally, the remaining protective layer in the third region is etched by HF (hydrogen fluoride) to complete the final microlens structure in the groove.

[0077] The method for manufacturing a microlens in a groove of the present invention is not only simple in process and low in cost, but also realizes a method for manufacturing a microlens in a groove with a depth greater than or equal to 50 μm. More importantly, the depth of the groove is precisely controlled, which is convenient for coupling with subsequent device mounting processes.

[0078] Example 1

[0079] Figure 2 The process steps of the method for manufacturing the microlens in the groove in the first embodiment of the present invention are shown.

[0080] refer to Figure 2 As shown in a in FIG. 1 , a substrate 10 is provided. The substrate 10 has a first region A, a second region B and a third region C.

[0081] refer to Figure 2 As shown in b, a conventional reflow hot melt process is used to make a glue ball micro lens surface shape 20 on the surface of the first area A of the substrate 10. The process involves the steps of coating, photolithography, development, reflow, etc. The diameter of the micro lens is 600 μm, and the ROC is 3800.

[0082] refer to Figure 2 As shown in Figure c, ICP etching is used to perform the first steady-state etching of the microlens. The etching gas is SF 6 / CHF 3 , gas flow rate is 25sccm, etching ICP is 700W, RF is 400W, pressure is 5mTorr, and etching time is 25min.

[0083] refer to Figure 2 As shown in d, the silicon oxide protective layer 30 is deposited by PECVD, the deposition temperature is 350°C, the power is 60W, the pressure is 110Pa, and the gas is SiH 4 and N 2 O, the deposition thickness is 500 μm.

[0084] refer to Figure 2As shown in FIG. 5 e, a window 41 exposing the first region A and the second region B is formed on the photoresist layer 40 by using a photolithography patterning technology, and the photoresist thickness is 10 μm.

[0085] refer to Figure 2 As shown in f, an etching method consistent with the first steady-state etching parameters is adopted to etch the silicon oxide protection layer 30 in the window 41 area, and the etching time is 80s.

[0086] refer to Figure 2 As shown in g, the first deep silicon etching process is used to etch the groove 50 (in the process of etching the groove, the microlens is also etched synchronously, thereby forming a microlens in the groove). This step uses a fast rate deep silicon etching process, the etching rate reaches 15μm / min, and the APC pressure is 20mTorr. In the passivation step of this process, the passivation gas is C 4 F 8 , flow rate is 400sccm, upper electrode power is 2500W, lower electrode power is 0, and passivation time is 2s. In the etching step of this process, the etching gas is SF 6 , flow rate is 500sccm, upper electrode power is 2000W, lower electrode power is 50W, etching time is 1.5s. The total etching time of the first deep silicon etching process is 19min.

[0087] refer to Figure 2 As shown in h, after the first rapid deep silicon etching, the stripping of the remaining photoresist layer 40 on the third area is completed through a stripping process, and the etching depth of the first rapid deep silicon etching can be accurately measured by a step instrument.

[0088] refer to Figure 2 As shown in Fig. 1, according to the measurement results, the second deep silicon etching process is used to complete the production of the microlens in the groove of the required depth. This step uses a slow rate deep silicon etching process with an etching rate of 1μm / min and an APC pressure of 30mTorr, which can accurately control the depth of the groove with a control tolerance within ±2μm. In the passivation step of this process, the passivation gas is C 4 F 8 , flow rate is 100sccm, upper electrode power is 1000W, lower electrode power is 0, and time is 1.5s. In the etching step of this process, the etching gas is SF 6 , flow rate is 80sccm, upper electrode power is 800W, lower electrode power is 30W, and time is 1.5s. The total etching time of the second deep silicon etching process is 10min.

[0089] refer to Figure 2As shown in j, by removing the silicon oxide protective layer 30 in the third region C with an HF solution, a microlens structure in the groove with a depth of nearly 300 μm and a depth tolerance of ±2 μm and a curvature radius of 3800 can be obtained.

[0090] The present invention also provides a micro-lens in a groove structure, which is manufactured by using the above-mentioned method for manufacturing the micro-lens in a groove.

[0091] Compared with the prior art, the method for manufacturing a microlens in a groove and the microlens in a groove structure of the present invention complete the transfer of the microlens through three etching processes, realize the manufacturing of the microlens in the groove, and can accurately control the depth of the groove, and control the groove depth error range within 2μm, which is suitable for the manufacturing of microlenses in ultra-deep grooves with a groove depth greater than or equal to 50μm.

[0092] In the method for manufacturing a microlens in a groove and the microlens in a groove structure of the present invention, the microlens or microlens array is located in the groove, and the groove wall not only plays a supporting and protective role to prevent the microlens from being dirty and scratched, but the depth of the groove can be used for the precise positioning of the subsequent optical chip.

[0093] The method for manufacturing a microlens in a groove and the microlens structure in a groove of the present invention, the three etching processes include one steady-state etching and two deep silicon etchings, the steady-state etching can realize the transfer of the microlens, the first deep silicon etching adopts fast-rate etching to form the groove structure contour, and the second deep silicon etching adopts slow-rate etching to realize the precise control of the groove structure depth.

[0094] The method for manufacturing the microlens in a groove and the microlens in a groove structure of the present invention form a protective layer after the first etching, which can provide an etching barrier layer for subsequent process etching.

[0095] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0096] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for manufacturing a microlens in a groove, characterized in that: The groove has a preset depth greater than the microlens sagittal height, and the manufacturing method comprises: Providing a substrate, the substrate having a first surface, the first surface including a first area, a second area surrounding the first area, and a third area surrounding the second area; forming a gumball microlens surface shape on a first area of ​​the first surface; Performing a first etching on the surface shape of the glue ball microlens and the first surface, replicating and transferring the surface shape of the glue ball microlens to the substrate to form a microlens; forming a protective layer on a surface of the substrate on which the microlens is formed; removing the protective layers in the first and second regions to expose the microlenses and the substrate; Performing a second etching on the microlens in the first region and the substrate in the second region at a first etching rate to form a microlens in the groove, wherein the depth of the second etching is less than the preset depth; The microlenses in the first region and the substrate in the second region are etched for a third time at a second etching rate so that the depth of the grooves in the microlenses in the grooves reaches the preset depth, and the second etching rate is less than the first etching rate.

2. The method for manufacturing a microlens in a groove according to claim 1, characterized in that: The first etching rate range is 10 μm / min-20 μm / min, and the pressure is 15 mTorr-40 mTorr; The second etching rate ranges from 1 μm / min to 2 μm / min, and the pressure ranges from 15 mTorr to 40 mTorr.

3. The method for manufacturing a microlens in a groove according to claim 1, characterized in that: The second etching and the third etching both adopt deep silicon etching method.

4. The method for manufacturing a microlens in a groove according to claim 3, characterized in that: During the second etching process, the passivation gas includes C4F8, the gas flow rate range is 500sccm-100sccm, the upper electrode power is 1500W-2500W, the lower electrode power is 0, and the passivation time is 1s-3s; The etching gas includes SF6, the gas flow range is 500sccm-100sccm, the upper electrode power is 1500W-2500W, the lower electrode power is 20W-100W, and the time is 1s-3s.

5. The method for manufacturing a microlens in a groove according to claim 3, characterized in that: During the third etching process, the passivation gas includes C4F8, the gas flow rate range is 100sccm-200sccm, the upper electrode power is 800W-1500W, the lower electrode power is 0, and the passivation time is 1s-3s; The etching gas includes SF6, the gas flow range is 80sccm-150sccm, the upper electrode power is 800W-1200W, the lower electrode power is 20W-100W, and the time is 1s-3s.

6. The method for manufacturing a microlens in a groove according to claim 1, characterized in that: The first etching adopts a steady-state etching method; and / or, The etching gas for the first etching is a fluorine-based gas, and the fluorine-based gas includes one or more of SF6, CF4, CHF3, and C4F8; and / or, The etching gas flow rate of the first etching is in the range of 20 sccm-40 sccm; and / or, The etching power of the first etching is 600W-1000W, the radio frequency power is 300W-500W, and the pressure is 3mTorr-10mTorr.

7. The method for manufacturing a microlens in a groove according to claim 1, characterized in that: The material of the protective layer includes silicon oxide; and / or, The protective layer is formed by plasma enhanced chemical vapor deposition, wherein the deposition temperature is 300° C.-350° C., the power is 50W-80W, the pressure is 100Pa-120Pa, and the reaction gas includes SiH4 and N2O; and / or, The deposition thickness of the protective layer is 500nm-1000nm; and / or The etching selection ratio of the protective layer to the substrate is (1:50)-(1:200).

8. The method for manufacturing a microlens in a groove according to claim 1, characterized in that: Removing the protective layer from the first region and the second region to expose the microlens and the substrate comprises: forming a photoresist layer on the surface of the protective layer; Etching the photoresist layer in the first region and the second region to expose the protective layer in the first region and the second region; The protective layers in the first region and the second region are etched by a steady-state etching method to expose the microlens and the substrate.

9. The method for manufacturing a microlens in a groove according to claim 8, characterized in that: When etching the protective layer, the etching gas is a fluorine-based gas, and the fluorine-based gas includes one or more of SF6, CF4, CHF3, and C4F8; the etching gas flow range is 20sccm-40sccm; the etching power is 600W-1000W, the RF power is 300W-500W, and the pressure is 3mTorr-10mTorr.

10. The method for manufacturing a microlens in a groove according to claim 8, characterized in that: Before the step of performing a second etching on the microlenses in the first area and the substrate in the second area, the method further includes: The step of removing the photoresist layer in the third area.

11. A microlens structure in a groove, characterized in that: The microlens in the groove is manufactured by the manufacturing method of any one of claims 1 to 10.

Images