CN105074576B - 极紫外光刻的光学元件和光学系统及处理这种光学元件的方法 - Google Patents
极紫外光刻的光学元件和光学系统及处理这种光学元件的方法 Download PDFInfo
- Publication number
- CN105074576B CN105074576B CN201480016112.4A CN201480016112A CN105074576B CN 105074576 B CN105074576 B CN 105074576B CN 201480016112 A CN201480016112 A CN 201480016112A CN 105074576 B CN105074576 B CN 105074576B
- Authority
- CN
- China
- Prior art keywords
- layer
- hydrogen
- optical element
- optical
- protective layer
- 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.)
- Active
Links
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
- G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
- G02B1/14—Protective coatings, e.g. hard coatings
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
- C23C16/56—After-treatment
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/08—Mirrors
- G02B5/0891—Ultraviolet [UV] mirrors
-
- 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
- G03F7/70—Microphotolithographic exposure; Apparatus therefor
- G03F7/70058—Mask illumination systems
- G03F7/7015—Details of optical elements
-
- 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
- G03F7/70—Microphotolithographic exposure; Apparatus therefor
- G03F7/70216—Mask projection systems
- G03F7/70316—Details of optical elements, e.g. of Bragg reflectors, extreme ultraviolet [EUV] multilayer or bilayer mirrors or diffractive optical elements
-
- 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
- G03F7/70—Microphotolithographic exposure; Apparatus therefor
- G03F7/708—Construction of apparatus, e.g. environment aspects, hygiene aspects or materials
- G03F7/70908—Hygiene, e.g. preventing apparatus pollution, mitigating effect of pollution or removing pollutants from apparatus
- G03F7/70916—Pollution mitigation, i.e. mitigating effect of contamination or debris, e.g. foil traps
-
- 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
- G03F7/70—Microphotolithographic exposure; Apparatus therefor
- G03F7/708—Construction of apparatus, e.g. environment aspects, hygiene aspects or materials
- G03F7/70908—Hygiene, e.g. preventing apparatus pollution, mitigating effect of pollution or removing pollutants from apparatus
- G03F7/70925—Cleaning, i.e. actively freeing apparatus from pollutants, e.g. using plasma cleaning
-
- 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
- G03F7/70—Microphotolithographic exposure; Apparatus therefor
- G03F7/708—Construction of apparatus, e.g. environment aspects, hygiene aspects or materials
- G03F7/7095—Materials, e.g. materials for housing, stage or other support having particular properties, e.g. weight, strength, conductivity, thermal expansion coefficient
- G03F7/70958—Optical materials or coatings, e.g. with particular transmittance, reflectance or anti-reflection properties
-
- 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
- G03F7/70—Microphotolithographic exposure; Apparatus therefor
- G03F7/708—Construction of apparatus, e.g. environment aspects, hygiene aspects or materials
- G03F7/70983—Optical system protection, e.g. pellicles or removable covers for protection of mask
-
- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21K—HANDLING OF PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
- G21K1/00—Arrangements for handling particles or ionising radiation, e.g. focusing or moderating
- G21K1/06—Arrangements for handling particles or ionising radiation, e.g. focusing or moderating using diffraction, refraction or reflection, e.g. monochromators
- G21K1/062—Devices having a multilayer structure
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Health & Medical Sciences (AREA)
- Epidemiology (AREA)
- Public Health (AREA)
- Environmental & Geological Engineering (AREA)
- Atmospheric Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Optics & Photonics (AREA)
- High Energy & Nuclear Physics (AREA)
- General Engineering & Computer Science (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Plasma & Fusion (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)
- Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US201361792638P | 2013-03-15 | 2013-03-15 | |
| DE201310102670 DE102013102670A1 (de) | 2013-03-15 | 2013-03-15 | Optisches Element und optisches System für die EUV-Lithographie sowie Verfahren zur Behandlung eines solchen optischen Elements |
| DE102013102670.2 | 2013-03-15 | ||
| US61/792,638 | 2013-03-15 | ||
| PCT/EP2014/050471 WO2014139694A1 (en) | 2013-03-15 | 2014-01-13 | Optical element and optical system for euv lithography, and method for treating such an optical element |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105074576A CN105074576A (zh) | 2015-11-18 |
| CN105074576B true CN105074576B (zh) | 2018-03-20 |
Family
ID=51519610
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201480016112.4A Active CN105074576B (zh) | 2013-03-15 | 2014-01-13 | 极紫外光刻的光学元件和光学系统及处理这种光学元件的方法 |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US10690812B2 (https=) |
| JP (1) | JP6382856B2 (https=) |
| KR (1) | KR102175814B1 (https=) |
| CN (1) | CN105074576B (https=) |
| DE (1) | DE102013102670A1 (https=) |
| WO (1) | WO2014139694A1 (https=) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI877233B (zh) * | 2019-09-30 | 2025-03-21 | 日商Hoya股份有限公司 | 附多層反射膜之基板、反射型光罩基底、反射型光罩及其製造方法、與半導體裝置之製造方法 |
| TWI918414B (zh) | 2019-09-30 | 2026-03-11 | 日商Hoya股份有限公司 | 附多層反射膜之基板、反射型光罩基底、反射型光罩、與半導體裝置之製造方法 |
Families Citing this family (27)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102013222330A1 (de) * | 2013-11-04 | 2015-05-07 | Carl Zeiss Smt Gmbh | Spiegel, insbesondere für eine mikrolithographische Projektionsbelichtungsanlage |
| JP6869242B2 (ja) * | 2015-11-19 | 2021-05-12 | エーエスエムエル ネザーランズ ビー.ブイ. | リソグラフィ装置のためのeuvソースチャンバーおよびガス流れ様式、多層ミラー、およびリソグラフィ装置 |
| DE102015225509A1 (de) * | 2015-12-16 | 2017-06-22 | Carl Zeiss Smt Gmbh | Reflektives optisches Element |
| US10128016B2 (en) * | 2016-01-12 | 2018-11-13 | Asml Netherlands B.V. | EUV element having barrier to hydrogen transport |
| DE102016208850A1 (de) * | 2016-05-23 | 2017-12-07 | Carl Zeiss Smt Gmbh | Projektionsbelichtungsanlage für die Halbleiterlithographie mit Elementen zur Plasmakonditionierung |
| DE102016213839A1 (de) | 2016-07-27 | 2016-12-15 | Carl Zeiss Smt Gmbh | Spiegel für ein mikrolithographisches Projektionsbelichtungssystem und Verfahren zur Bearbeitung eines Spiegels |
| DE102016213831A1 (de) | 2016-07-27 | 2018-02-01 | Carl Zeiss Smt Gmbh | Reflektives optisches Element für die EUV-Lithographie |
| KR102707462B1 (ko) * | 2016-09-06 | 2024-09-23 | 삼성전자주식회사 | 포토마스크 |
| DE102016223206A1 (de) | 2016-11-23 | 2017-01-12 | Carl Zeiss Smt Gmbh | Verfahren zur aufarbeitung reflektiver optischer elemente für ultraviolette strahlung oder weiche röntgenstrahlung |
| DE102016224200A1 (de) | 2016-12-06 | 2018-06-07 | Carl Zeiss Smt Gmbh | Verfahren zum Reparieren von reflektiven optischen Elementen für die EUV-Lithographie |
| DE102016226202A1 (de) * | 2016-12-23 | 2018-06-28 | Carl Zeiss Smt Gmbh | Optisches Element, insbesondere für eine mikrolithographische Projektionsbelichtungsanlage |
| DE102017200667A1 (de) | 2017-01-17 | 2018-07-19 | Carl Zeiss Smt Gmbh | Spiegel, insbesondere für eine mikrolithographische Projektionsbelichtungsanlage oder ein Inspektionssystem |
| DE102017206256A1 (de) | 2017-04-11 | 2018-10-11 | Carl Zeiss Smt Gmbh | Wellenfrontkorrekturelement zur Verwendung in einem optischen System |
| DE102017213181A1 (de) * | 2017-07-31 | 2019-01-31 | Carl Zeiss Smt Gmbh | Optische Anordnung für EUV-Strahlung mit einer Abschirmung zum Schutz vor der Ätzwirkung eines Plasmas |
| DE102017213176A1 (de) | 2017-07-31 | 2017-09-21 | Carl Zeiss Smt Gmbh | Optisches Element für die EUV-Lithographie und EUV-Lithographiesystem damit |
| KR102402767B1 (ko) * | 2017-12-21 | 2022-05-26 | 삼성전자주식회사 | 극자외선 마스크 블랭크, 극자외선 마스크 블랭크를 이용하여 제조된 포토마스크, 포토마스크를 이용한 리소그래피 장치 및 포토마스크를 이용한 반도체 장치 제조 방법 |
| DE102018211980A1 (de) * | 2018-07-18 | 2019-09-05 | Carl Zeiss Smt Gmbh | Reflektives optisches Element |
| DE102018221190A1 (de) * | 2018-12-07 | 2020-06-10 | Carl Zeiss Smt Gmbh | Verfahren zum Bilden von Nanostrukturen an einer Oberfläche und Wafer-Inspektionssystem |
| TWI833025B (zh) | 2019-06-20 | 2024-02-21 | 日商Hoya股份有限公司 | 反射型遮罩基底、反射型遮罩、以及反射型遮罩及半導體裝置之製造方法 |
| DE102019212910A1 (de) * | 2019-08-28 | 2021-03-04 | Carl Zeiss Smt Gmbh | Optisches Element und EUV-Lithographiesystem |
| DE102019213349A1 (de) | 2019-09-03 | 2021-03-04 | Carl Zeiss Smt Gmbh | Spiegelanordnung mit Wasserstoff-Barriere und optische Anordnung |
| DE102020206117A1 (de) | 2020-05-14 | 2021-11-18 | Carl Zeiss Smt Gmbh | Optisches Element, EUV-Lithographiesystem und Verfahren zum Bilden von Nanopartikeln |
| US12510692B2 (en) | 2020-08-27 | 2025-12-30 | Kla Corporation | Protection of optical materials of optical components from radiation degradation |
| US11402743B2 (en) * | 2020-08-31 | 2022-08-02 | Taiwan Semiconductor Manufacturing Co., Ltd. | Mask defect prevention |
| KR20220123918A (ko) * | 2021-03-02 | 2022-09-13 | 에스케이하이닉스 주식회사 | 극자외선 마스크 및 극자외선 마스크를 이용하여 제조된 포토마스크 |
| DE102022202059A1 (de) * | 2022-03-01 | 2023-09-07 | Carl Zeiss Smt Gmbh | Verfahren zum Bearbeiten eines Werkstücks |
| DE102024111387A1 (de) | 2023-05-30 | 2024-12-05 | Carl Zeiss Smt Gmbh | EUV-Lithographiesystem und Verfahren zum Herstellen eines optischen Elements und/oder eines nicht-optischen Bauteils |
Family Cites Families (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4439870A (en) * | 1981-12-28 | 1984-03-27 | Bell Telephone Laboratories, Incorporated | X-Ray source and method of making same |
| US6664554B2 (en) * | 2001-01-03 | 2003-12-16 | Euv Llc | Self-cleaning optic for extreme ultraviolet lithography |
| US20030008148A1 (en) * | 2001-07-03 | 2003-01-09 | Sasa Bajt | Optimized capping layers for EUV multilayers |
| EP1402542B1 (en) * | 2001-07-03 | 2007-09-26 | EUV Limited Liability Corporation | Passivating overcoat bilayer |
| US6756163B2 (en) * | 2002-06-27 | 2004-06-29 | Intel Corporation | Re-usable extreme ultraviolet lithography multilayer mask blank |
| DE10309084A1 (de) | 2003-03-03 | 2004-09-16 | Carl Zeiss Smt Ag | Reflektives optisches Element und EUV-Lithographiegerät |
| US20060127780A1 (en) * | 2004-12-15 | 2006-06-15 | Manish Chandhok | Forming a capping layer for a EUV mask and structures formed thereby |
| JP2006173490A (ja) * | 2004-12-17 | 2006-06-29 | Nikon Corp | 光学素子及びこれを用いた投影露光装置 |
| US7875863B2 (en) * | 2006-12-22 | 2011-01-25 | Asml Netherlands B.V. | Illumination system, lithographic apparatus, mirror, method of removing contamination from a mirror and device manufacturing method |
| EP2210147B1 (en) * | 2007-10-02 | 2013-05-22 | Universita Degli Studi Di Padova | Aperiodic multilayer structures |
| JP2010192503A (ja) * | 2009-02-16 | 2010-09-02 | Seiko Epson Corp | フォトマスクおよびフォトマスクの製造方法 |
| EP2513686B1 (en) | 2009-12-15 | 2019-04-10 | Carl Zeiss SMT GmbH | Reflective optical element for euv lithography |
| DE102009054653A1 (de) * | 2009-12-15 | 2011-06-16 | Carl Zeiss Smt Gmbh | Spiegel für den EUV-Wellenlängenbereich, Substrat für einen solchen Spiegel, Verwendung einer Quarzschicht für ein solches Substrat, Projektionsobjektiv für die Mikrolithographie mit einem solchen Spiegel oder einem solchen Substrat und Projetktionsbelichtungsanlage für die Mikrolithographie mit einem solchen Projektionsobjektiv |
| JP5091956B2 (ja) | 2010-01-15 | 2012-12-05 | パナソニック株式会社 | 火災警報システム |
| CN102621815B (zh) * | 2011-01-26 | 2016-12-21 | Asml荷兰有限公司 | 用于光刻设备的反射光学部件及器件制造方法 |
| DE102011076011A1 (de) | 2011-05-18 | 2012-11-22 | Carl Zeiss Smt Gmbh | Reflektives optisches Element und optisches System für die EUV-Lithographie |
| US9349593B2 (en) * | 2012-12-03 | 2016-05-24 | Semiconductor Energy Laboratory Co., Ltd. | Method for manufacturing semiconductor device |
-
2013
- 2013-03-15 DE DE201310102670 patent/DE102013102670A1/de not_active Ceased
-
2014
- 2014-01-13 WO PCT/EP2014/050471 patent/WO2014139694A1/en not_active Ceased
- 2014-01-13 CN CN201480016112.4A patent/CN105074576B/zh active Active
- 2014-01-13 KR KR1020157028007A patent/KR102175814B1/ko active Active
- 2014-01-13 JP JP2015561983A patent/JP6382856B2/ja active Active
-
2015
- 2015-09-15 US US14/854,784 patent/US10690812B2/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI877233B (zh) * | 2019-09-30 | 2025-03-21 | 日商Hoya股份有限公司 | 附多層反射膜之基板、反射型光罩基底、反射型光罩及其製造方法、與半導體裝置之製造方法 |
| TWI918414B (zh) | 2019-09-30 | 2026-03-11 | 日商Hoya股份有限公司 | 附多層反射膜之基板、反射型光罩基底、反射型光罩、與半導體裝置之製造方法 |
Also Published As
| Publication number | Publication date |
|---|---|
| US10690812B2 (en) | 2020-06-23 |
| KR20150130410A (ko) | 2015-11-23 |
| KR102175814B1 (ko) | 2020-11-09 |
| US20160187543A1 (en) | 2016-06-30 |
| JP2016509270A (ja) | 2016-03-24 |
| CN105074576A (zh) | 2015-11-18 |
| DE102013102670A1 (de) | 2014-10-02 |
| WO2014139694A1 (en) | 2014-09-18 |
| JP6382856B2 (ja) | 2018-08-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105074576B (zh) | 极紫外光刻的光学元件和光学系统及处理这种光学元件的方法 | |
| US12474629B2 (en) | Membrane for EUV lithography | |
| EP2710415B1 (en) | Reflective optical element and optical system for euv lithography | |
| CN103635974B (zh) | 制造用于euv光刻的反射光学元件的方法 | |
| CN102576196A (zh) | 反射光学元件和用于操作euv光刻设备的方法 | |
| US20230050613A1 (en) | Pellicle membrane for a lithographic apparatus | |
| DE102020213639A1 (de) | Optisches Element, insbesondere zur Reflexion von EUV-Strahlung, optische Anordnung und Verfahren zum Herstellen eines optischen Elements | |
| JP2022546442A (ja) | 光学素子及びeuvリソグラフィシステム | |
| DE102020206117A1 (de) | Optisches Element, EUV-Lithographiesystem und Verfahren zum Bilden von Nanopartikeln |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |