CN116577871A - 基于深硅刻蚀的光纤与硅光芯片高精度耦合实现方法 - Google Patents
基于深硅刻蚀的光纤与硅光芯片高精度耦合实现方法 Download PDFInfo
- Publication number
- CN116577871A CN116577871A CN202310572186.7A CN202310572186A CN116577871A CN 116577871 A CN116577871 A CN 116577871A CN 202310572186 A CN202310572186 A CN 202310572186A CN 116577871 A CN116577871 A CN 116577871A
- Authority
- CN
- China
- Prior art keywords
- etching
- silicon
- coupling
- silicon etching
- optical fiber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 title claims abstract description 69
- 238000005530 etching Methods 0.000 title claims abstract description 69
- 229910052710 silicon Inorganic materials 0.000 title claims abstract description 69
- 239000010703 silicon Substances 0.000 title claims abstract description 69
- 238000010168 coupling process Methods 0.000 title claims abstract description 39
- 230000008878 coupling Effects 0.000 title claims abstract description 36
- 238000005859 coupling reaction Methods 0.000 title claims abstract description 36
- 239000013307 optical fiber Substances 0.000 title claims abstract description 33
- 230000003287 optical effect Effects 0.000 title claims abstract description 17
- 238000000034 method Methods 0.000 title claims description 16
- 238000005253 cladding Methods 0.000 claims abstract description 26
- 229920002120 photoresistant polymer Polymers 0.000 claims abstract description 20
- 239000000758 substrate Substances 0.000 claims abstract description 10
- 238000001259 photo etching Methods 0.000 claims abstract description 9
- 239000000463 material Substances 0.000 claims abstract description 8
- 229910018503 SF6 Inorganic materials 0.000 claims abstract description 6
- SFZCNBIFKDRMGX-UHFFFAOYSA-N sulfur hexafluoride Chemical compound FS(F)(F)(F)(F)F SFZCNBIFKDRMGX-UHFFFAOYSA-N 0.000 claims abstract description 6
- 229960000909 sulfur hexafluoride Drugs 0.000 claims abstract description 6
- 239000007789 gas Substances 0.000 claims description 11
- 238000002161 passivation Methods 0.000 claims description 10
- 230000008021 deposition Effects 0.000 claims description 6
- 229920002313 fluoropolymer Polymers 0.000 claims description 4
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 claims description 2
- 238000006243 chemical reaction Methods 0.000 claims description 2
- 238000005137 deposition process Methods 0.000 claims description 2
- 238000010494 dissociation reaction Methods 0.000 claims description 2
- 230000005593 dissociations Effects 0.000 claims description 2
- 230000002045 lasting effect Effects 0.000 claims description 2
- 238000004528 spin coating Methods 0.000 abstract description 3
- 239000000835 fiber Substances 0.000 description 7
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 238000000151 deposition Methods 0.000 description 3
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000002708 enhancing effect Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 239000013043 chemical agent Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000001312 dry etching Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- 230000036571 hydration Effects 0.000 description 1
- 238000006703 hydration reaction Methods 0.000 description 1
- 238000001000 micrograph Methods 0.000 description 1
- 230000005693 optoelectronics Effects 0.000 description 1
- 238000012536 packaging technology Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 239000012495 reaction gas Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
- G02B6/13—Integrated optical circuits characterised by the manufacturing method
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
- G02B6/13—Integrated optical circuits characterised by the manufacturing method
- G02B6/136—Integrated optical circuits characterised by the manufacturing method by etching
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/0035—Multiple processes, e.g. applying a further resist layer on an already in a previously step, processed pattern or textured surface
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/20—Exposure; Apparatus therefor
- G03F7/2002—Exposure; Apparatus therefor with visible light or UV light, through an original having an opaque pattern on a transparent support, e.g. film printing, projection printing; by reflection of visible or UV light from an original such as a printed image
- G03F7/2004—Exposure; Apparatus therefor with visible light or UV light, through an original having an opaque pattern on a transparent support, e.g. film printing, projection printing; by reflection of visible or UV light from an original such as a printed image characterised by the use of a particular light source, e.g. fluorescent lamps or deep UV light
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
- G02B2006/12166—Manufacturing methods
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
- G02B2006/12166—Manufacturing methods
- G02B2006/12173—Masking
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
- G02B2006/12166—Manufacturing methods
- G02B2006/12176—Etching
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Optics & Photonics (AREA)
- Optical Couplings Of Light Guides (AREA)
- Optical Integrated Circuits (AREA)
Abstract
一种基于深硅刻蚀的光纤与硅光芯片高精度耦合实现方法,通过在在衬底上旋涂光刻胶后进行掩膜对准式曝光;然后采用包层刻蚀去除顶部和底部包层材料后利用C4F8和SF6进行深硅刻蚀实现高深宽比、侧壁陡直的硅刻蚀;最后将晶片解理成独立芯片,其台阶状的沟道用于与光纤进行耦合。本发明通过特定深度深硅刻蚀槽图形,运用光刻及深硅刻蚀手段制备特定深度的深硅刻蚀槽,利用光刻和刻蚀的高精度从而实现光纤到芯片上波导耦合条件,如高度、距离等的精确控制,有效提高耦合容差和耦合鲁棒性。
Description
技术领域
本发明涉及的是一种光芯片领域的技术,具体是一种基于深硅刻蚀的光纤与硅光芯片高精度耦合实现方法。
背景技术
集成光子学领域取得了巨大的发展。由于具有低成本、高性能、小尺寸和半导体大规模制造兼容性等优点,硅基光电子器件成为了集成光子学的研究热点。但由于光纤的芯径与芯片内波导的截面尺寸相差较大,芯片内光信号与片外光信号的耦合连接成为了硅基光电芯片封装技术的关键部分。以C波段(约1550nm)光波导为例,其理论宽度为450nm、厚度为220nm,其中传输的光场的模场直径(MFD)约为0.3μm,而单模光纤的模场直径约为9μm,二者之间存在巨大的模场失配。目前常用的平面波导类耦合方法是通过光纤阵列(FA,FiberArray)与芯片端面波导对准耦合。但由于该方法所选用的硬胶会随环境变化而产生较大应力,因此并不适用于悬臂梁波导芯片耦合。此外,若芯片端面底部有凸起则无法使用常规光纤阵列,要定制特定规格光纤阵列用于耦合对准,该类光纤阵列制作工艺复杂,加工难度较高,
成本昂贵,与芯片耦合工艺复杂。
发明内容
本发明针对现有技术存在的上述不足,提出一种基于深硅刻蚀的光纤与硅光芯片高精度耦合实现方法,通过特定深度深硅刻蚀槽图形,运用光刻、包层刻蚀及深硅刻蚀手段制备特定深度的深硅刻蚀槽,利用光刻和刻蚀的高精度从而实现光纤到芯片上波导耦合条件,如高度、距离等的精确控制,有效提高耦合容差和耦合鲁棒性。
本发明是通过以下技术方案实现的:
本发明涉及一种基于深硅刻蚀的光纤与硅光芯片高精度耦合实现方法,通过在在衬底上旋涂光刻胶后进行掩膜对准式曝光;然后采用包层刻蚀去除顶部和底部包层材料后利用C4F8和SF6进行深硅刻蚀实现高深宽比、侧壁陡直的硅刻蚀;最后将晶片解理成独立芯片,其台阶状的沟道用于与光纤进行耦合。
所述的耦合的位置由光刻、包层刻蚀及深硅刻蚀得到的深硅刻蚀槽的位置决定,利用光刻和刻蚀的参数实现耦合参数的精确控制。
所述的旋涂,使用光刻胶如(MegapositSPR220-4.5)作为蚀刻掩模,将光刻胶以2500转/分的速度旋转60秒,得到厚度约5μm的光刻胶,随后在115℃下烘烤3分钟,将光刻胶中的溶剂蒸发,增强光刻胶对芯片的附着力。
所述的掩膜对准式曝光,使用掩膜对准曝光机,应用紫外光源曝光20-25秒,曝光后进行烘烤和显影以降低曝光导致的驻波效应;最后进行水合处理使水扩散回光刻胶。
所述的烘烤,在115℃下进行曝光后烘烤约3分钟。
所述的包层刻蚀,采用但不限于氧化物刻蚀。
所述的氧化物刻蚀采用的反应气体为CHF3、O2或者Ar,对上、下包层的材料进行全刻蚀。
所述的深硅刻蚀的深度为使用光纤的半径减去底部包层材料的厚度。
所述的深硅刻蚀,采用基于刻蚀和钝化交替进行,具体步骤包括:
a)碳氟聚合物沉积形成钝化层:使用C4F8气体作为沉积气体,沉积过程中形成等离子体附着在硅上并形成钝化膜,防止侧壁被蚀刻。
b)硅刻蚀:使用SF6气体作为硅蚀刻的蚀刻气体,SF6气体在等离子体中离解形成SF4或SF2以及能够参与硅蚀刻反应反应的原子氟。
所述的交替进行是指:碳氟聚合物沉积形成钝化层与钝化层与硅刻蚀工艺进行快速切换,每个阶段持续0.1-9s并重复多次刻蚀-钝化,导致各向同性蚀刻步骤仅蚀刻底部而不影响侧壁。
本发明涉及上述方法制备得到的基于深硅刻蚀的光纤硅光芯片耦合结构,包括衬底和位于其上的SiO2包层、Si3N4或硅波导和光纤,其中:SiO2包层包覆于Si3N4或硅波导外部,Si3N4或硅波导与光纤耦合连接。
附图说明
图1为本发明制备工艺流程图;
图2为本发明工艺示意图;
图中:a为刻蚀前的硅芯片,b为刻蚀后的硅芯片;
图3为本发明波导-光纤耦合结构俯视图;
图4为波导-光纤耦合结构侧视图;
图中:SiO2包层1、Si3N4波导2、衬底3、光纤4
图5为深硅刻蚀的端面扫描电镜图;
图6为深硅刻蚀结构的扫描电镜的侧视图。
具体实施方式
如图1所示,为本实施例涉及上述耦合结构的制备方法,包括:
步骤1)采用用化学试剂(如硫酸、过氧化氢等)清洁衬底3,
步骤2)使用光刻胶如(MegapositSPR220-4.5)作为蚀刻掩模,将光刻胶以2500转/分的速度旋转60秒,得到厚度约5μm的光刻胶,随后在115℃下烘烤3分钟,将光刻胶中的溶剂蒸发,增强光刻胶对芯片的附着力。
步骤3)使用掩膜对准曝光机(如MicroTechMA/BA6),应用紫外光源,进行掩膜对准式曝光。
本实施例中光刻胶曝光时间为22秒;
为了降低曝光导致的驻波效应,曝光后在115℃下进行曝光后烘烤(PEB)约3分钟,并用显影液如AZ300MIF进行显影,大概用时3分钟。
由于本实施例中光刻胶的厚度较厚(大于4μm),需要将其再水合35分钟以上,使水扩散回光刻胶。
步骤4)对所获得图形进行干法刻蚀:通过氧化物刻蚀去除顶部和底部包层材料(大多数情况下包层材料为二氧化硅,采用的反应气体为CHF3、O2或者Ar。
步骤5)之后利用C4F8和SF6进行深硅干法刻蚀,刻蚀的深度为使用光纤的半径减去底部包层材料的厚度。
在本实施例中,由于采用的耦合光纤是SMF-28单模光纤,并且芯片的底部包层厚度为3微米,所以所需硅衬底的刻蚀深度为59.5微米,宽度为125微米的矩形,从而形成耦合面以便光纤直接接入。
步骤6)将晶片分割解理成单独的芯片,切割过程中划片刀片无需接触器件的边缘。
由于深硅刻蚀工艺依赖于硅蚀刻在光刻胶上的良好选择性,所以如果选择性较低,则需要增加光刻胶厚度。
如图2和图3所示,为本实施例涉及的一种基于深硅刻蚀的光纤硅光芯片耦合结构,包括衬底3和位于其上的SiO2包层1、Si3N4波导2和光纤4,其中:SiO2包层1包覆于Si3N4波导2外部,Si3N4波导2与光纤4耦合连接。
如图5,6所示,实际得到的芯片与光纤耦合面平整且光滑,并且得到了台阶状的沟道,可以直接与光纤进行耦合。
与现有技术相比,本发明拟通过设计特定深度的深硅刻蚀图形,通过光刻及刻蚀形成特定深度的深硅刻蚀槽,进而实现精确控制光纤和芯片刻蚀面的耦合条件,如高度、距离等,有效提高耦合容差和耦合鲁棒性。
上述具体实施可由本领域技术人员在不背离本发明原理和宗旨的前提下以不同的方式对其进行局部调整,本发明的保护范围以权利要求书为准且不由上述具体实施所限,在其范围内的各个实现方案均受本发明之约束。
Claims (4)
1.一种基于深硅刻蚀的光纤与硅光芯片高精度耦合实现方法,其特征在于,通过在在衬底上旋涂光刻胶后进行掩膜对准式曝光;然后采用包层刻蚀去除顶部和底部包层材料后利用C4F8和SF6进行深硅刻蚀实现高深宽比、侧壁陡直的硅刻蚀;最后将晶片解理成独立芯片,其台阶状的沟道用于与光纤进行耦合。
2.根据权利要求1所述的基于深硅刻蚀的光纤与硅光芯片高精度耦合实现方法,其特征是,所述的耦合的位置由光刻、包层刻蚀及深硅刻蚀得到的深硅刻蚀槽的位置决定,利用光刻和刻蚀的参数实现耦合参数的精确控制。
3.根据权利要求1所述的基于深硅刻蚀的光纤与硅光芯片高精度耦合实现方法,其特征是,所述的深硅刻蚀,采用基于刻蚀和钝化交替进行,具体步骤包括:
a)碳氟聚合物沉积形成钝化层:使用C4F8气体作为沉积气体,沉积过程中形成等离子体附着在硅上并形成钝化膜,防止侧壁被蚀刻;
b)硅刻蚀:使用SF6气体作为薄膜蚀刻和硅蚀刻的蚀刻气体,SF6气体在等离子体中离解形成SF4或SF2以及能够参与蚀刻反应反应的原子氟;
所述的的交替进行是指:碳氟聚合物沉积形成钝化层与钝化层与硅刻蚀工艺进行快速切换,每个阶段持续0.1-9s并重复多次刻蚀-钝化,导致各向同性蚀刻步骤仅蚀刻底部而不影响侧壁。
4.一种根据权利要求1-3中任一所述方法制备得到的光纤硅光芯片耦合结构,其特征在于,包括衬底和位于其上的SiO2包层、Si3N4或硅波导和光纤,其中:SiO2包层包覆于Si3N4或硅波导外部,Si3N4或硅波导与光纤耦合连接。
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202310572186.7A CN116577871A (zh) | 2023-05-22 | 2023-05-22 | 基于深硅刻蚀的光纤与硅光芯片高精度耦合实现方法 |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202310572186.7A CN116577871A (zh) | 2023-05-22 | 2023-05-22 | 基于深硅刻蚀的光纤与硅光芯片高精度耦合实现方法 |
Publications (1)
Publication Number | Publication Date |
---|---|
CN116577871A true CN116577871A (zh) | 2023-08-11 |
Family
ID=87539310
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202310572186.7A Pending CN116577871A (zh) | 2023-05-22 | 2023-05-22 | 基于深硅刻蚀的光纤与硅光芯片高精度耦合实现方法 |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN116577871A (zh) |
-
2023
- 2023-05-22 CN CN202310572186.7A patent/CN116577871A/zh active Pending
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US9103972B2 (en) | Optical waveguide structure with waveguide coupler to facilitate off-chip coupling | |
JP2019519914A (ja) | シリコンフォトニクスにおけるiii−vチップの作成および集積化 | |
CN102323646B (zh) | 光栅耦合器及其制作方法 | |
TWI768794B (zh) | 光學裝置與其製造方法 | |
US10261106B2 (en) | Photonic probe for atomic force microscopy | |
JP2008505355A (ja) | 一体型整列機構を有する光導波路アセンブリを製造するための方法 | |
JP4688892B2 (ja) | 走査探針顕微鏡に用いられる探針ティップ及び探針の製造方法 | |
CN114296182A (zh) | 一种基于硅基光波导的三维光交叉器及其制备方法 | |
JP2011523466A (ja) | 薄いペリクルビームスプリッタの製造 | |
CN116577871A (zh) | 基于深硅刻蚀的光纤与硅光芯片高精度耦合实现方法 | |
CN102004281A (zh) | 低粗糙度的光波导器件的制造方法 | |
Wang et al. | CMOS-compatible silicon etched U-grooves with groove-first fabrication for nanophotonic applications | |
CN112925059A (zh) | 一种片上集成波导的微盘腔及其制备方法 | |
WO2023092291A1 (zh) | 一种芯片中光波导结构的刻蚀方法、芯片以及光通信设备 | |
CN112612078B (zh) | 一种基于goi或soi上的高效耦合波导及其制备方法 | |
CN215494219U (zh) | 一种片上集成波导的微盘腔 | |
CN109417266B (zh) | 硅光子学中的iii-v芯片制备和集成 | |
JP4681644B2 (ja) | 光導波路の作製方法 | |
KR100342480B1 (ko) | 상이한 깊이를 가진 박막층에 의한 3차원 실리콘 웨이퍼제조 방법 | |
CN114428377B (zh) | 与一个或多个气隙集成的光栅耦合器 | |
Lunt | Low-loss hollow waveguide platforms for optical sensing and manipulation | |
CN111487716B (zh) | 一种减小波导尖端尺寸的方法 | |
JPH05182948A (ja) | 薄膜テーパー構造の形成方法 | |
CN114895401A (zh) | 一种硅光子芯片光耦合结构及其制造方法 | |
US11320589B1 (en) | Grating couplers integrated with one or more airgaps |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
PB01 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
SE01 | Entry into force of request for substantive examination |