# US 2003/0107815 A1 · Micro lens and method and apparatus for fabricating > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2003/0107815 A1 - Document ID: US20030107815A1 - Status: Published application - Kind: A1 - Application number: 10/278,719 - Filed: 2002-10-22 - Published: 2003-06-12 - Earliest claimed: 2000-09-20 - Assignees: DataPlay, Inc. - Inventors: Ian R. Redmond - Web page: https://patentgrep.com/patent/US20030107815A1 ## CPC - G11B 7/1353: Diffractive elements, e.g. holograms or gratings {(diffraction gratings per se G02B5/18; holograms per se G02B5/32; grating systems G02B27/44)} - G02B 3/00: Simple or compound lenses - G11B 7/1374: Objective lenses {(optical objectives per se G02B9/00)} - G11B 7/13922: {passive} - G11B 7/22: Apparatus or processes for the manufacture of optical heads, e.g. assembly - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract Micro lenses are fabricated using processes which operate on multiple lenses at a time. In one embodiment, wafer-scale processing includes employing photolithography for defining gray-scale masks which permit relatively smooth or continuous curvatures of lens surfaces to be formed by, e.g., reactive ion etching. Processes and materials are used which achieve desired etching at a sufficiently rapid rate such as etching to a depth of about 200 micrometers in less than about 10 hours. Wafer-scale molding processes can also be used. Diffractive features can be formed on or adjacent lens surfaces to provide functions such as dispersion correction. Also, sub-wavelength scale features may be etched to provide quarter-wave plate functionality, birefringence, anti-reflective functions and the like. Structures such as mounting rings and/or crash stops can be formed integrally with the lens body, eliminating the need to glue or otherwise couple separate components. ## Claims ### Claim 1 A method for forming microlenses having diameters less than about 1 mm comprising: positioning a photomask with respect to a wafer to define a plurality of etchable regions corresponding to desired positions of lenses; selectively removing material from said wafer by a process which includes etching said wafer substantially simultaneously at least in said etchable regions; cutting said wafer along a plurality of cut lines to separate into a plurality of dice, at least a first number of said dice, each having at least one etched lens thereon. ### Claim 2 (depends on 1) A method a claimed in claim 1 wherein said microlenses have a sag depth of at least about 100 micrometers and wherein said etching is performed in less than about 10 hours. ### Claim 3 (depends on 1) A method as claimed in claim 1 wherein said wafer includes a material selected from the group consisting of ZnSe, gallium phosphide or fused silica. ### Claim 4 (depends on 1) A method as claimed in claim 1 wherein said etching comprises a reactive ion etch. ### Claim 5 (depends on 1) A method as claimed in claim 1 wherein said photomask comprises a gray-scale mask. ### Claim 6 (depends on 1) A method as claimed in claim 1 wherein said photomask comprises multiple binary level masks. ### Claim 7 (depends on 1) A method as claimed in claim 1 wherein said number of dice formed with at least one lens from a single wafer is at least about 1,000. ### Claim 8 (depends on 1) A method as claimed in claim 1 further comprising selectively coating at least a first surface of said wafer with a reflective or opaque coating. ### Claim 9 (depends on 1) A method as claimed in claim 1 further comprising forming at least a first diffractive optic on a plurality of regions of said wafer. ### Claim 10 (depends on 1) A method as claimed in claim 1 wherein said lenses are configured for use with at least a first wavelength of light and further comprising forming sub-wavelength features in a plurality of regions of said wafer. ### Claim 11 (depends on 10) A method as claimed in claim 10 wherein said sub-wavelength features provide at least one of a quarter wave plate functionality, birefringence, or anti-reflective functionality. ### Claim 12 (depends on 1) A method as claimed in claim 1 wherein surfaces of said lenses are positioned recessed from an adjacent region of said wafer. ### Claim 13 (depends on 12) A method as claimed in claim 12 wherein said adjacent region is configured to provide a crash stop. ### Claim 14 (depends on 12) A method as claimed in claim 12 wherein said adjacent region is configured to provide a lens mount. ### Claim 15 (depends on 12) A method as claimed in claim 12 wherein said adjacent region is used to form at least a portion of an aperture stop. ### Claim 16 (depends on 15) A method as claimed in claim 15 wherein said aperture stop is formed by a process which includes providing a reflective or opaque coating on at least a portion of said adjacent region. ### Claim 17 (depends on 1) A method as claimed in claim 1 wherein said microlenses have an index of refraction of at least about 1.4. ### Claim 18 (depends on 1) A method as claimed in claim 1 wherein etching is used to position first and second lens surfaces aligned with one another on opposite surfaces of said wafer. ### Claim 19 (depends on 9) A method as claimed in claim 9 wherein said diffractive optic is a hologram. ### Claim 20 (depends on 9) A method as claimed in claim 9 wherein said diffractive optic is configured to provide dispersion compensation. ### Claim 21 Apparatus for forming microlenses having diameters less than about 1 mm comprising: a wafer having a plurality of etchable regions defined thereon by a photomask, said plurality of etchable regions corresponding to desired positions of lenses; etching means for selectively removing material from said wafer substantially simultaneously in at least said plurality of etchable regions; separating means for separating said wafer along a plurality of cut lines into a plurality of dice, at least a first number of said dice, each having at least one etched microlens thereon. ### Claim 22 (depends on 21) Apparatus as claimed in claim 21 wherein at least some of said microlenses have a sag depth of at least about 100 micrometers and wherein said etching is performed in less than about 10 hours. ### Claim 23 (depends on 21) Apparatus as claimed in claim 21 wherein said wafer includes a material selected from the group consisting of ZnSe, gallium phosphide or fused silica. ### Claim 24 (depends on 21) Apparatus as claimed in claim 21 wherein said etching means comprises means for performing a reactive ion etch. ### Claim 25 (depends on 21) Apparatus as claimed in claim 21 wherein said photomask comprises a gray-scale mask. ### Claim 26 (depends on 21) Apparatus as claimed in claim 21 wherein said photomask comprises multiple binary level masks. ### Claim 27 (depends on 21) Apparatus as claimed in claim 21 wherein said number of dice formed with at least one microlens from a single wafer is at least about 1,000. ### Claim 28 (depends on 21) Apparatus as claimed in claim 21 further comprising a reflective or opaque coating selectively positioned on at least portions of at least a first surface of said wafer. ### Claim 29 (depends on 21) Apparatus as claimed in claim 21 further comprising at least a first diffractive optic pattern positioned on a plurality of regions of said wafer. ### Claim 30 (depends on 29) Apparatus as claimed in claim 29 wherein said diffractive optic is a hologram. ### Claim 31 (depends on 29) Apparatus as claimed in claim 29 wherein said diffractive optic is configured to provide dispersion compensation. ### Claim 32 (depends on 21) Apparatus as claimed in claim 21 further comprising positioned means for providing at least one of a quarter wave plate functionality, birefringence, or anti-reflective functionality. ### Claim 33 (depends on 21) Apparatus as claimed in claim 21 wherein said microlenses are configured for use with at least a first wavelength of light and wherein said means for providing comprise sub-wavelength features in a plurality of regions of said wafer. ### Claim 34 (depends on 21) Apparatus as claimed in claim 21 wherein surfaces of said lenses are positioned recessed from an adjacent region of said wafer. ### Claim 35 (depends on 34) Apparatus as claimed in claim 34 wherein said adjacent region is configured to provide a crash stop. ### Claim 36 (depends on 34) Apparatus as claimed in claim 34 wherein said adjacent region is configured to provide a lens mount. ### Claim 37 (depends on 34) Apparatus as claimed in claim 34 wherein said adjacent region is used to form at least a portion of an aperture stop. ### Claim 38 (depends on 37) Apparatus as claimed in claim 37 wherein said aperture stop is formed by a process which includes providing a reflective or opaque coating on at least a portion of said adjacent region. ### Claim 39 (depends on 21) Apparatus as claimed in claim 21 wherein said microlenses have an index of refraction of at least about 1.4. ### Claim 40 (depends on 21) Apparatus as claimed in claim 21 wherein said means for etching is used to position first and second lens' surfaces aligned with one another on opposite surfaces of said wafer. ### Claim 41 A microlens assembly comprising: first and second opposed lens surfaces etched from portions of opposed surfaces of a substrate to provide a first microlens; a structure adjacent at least a portion of the perimeter of said first or second lens surfaces, said structure being at least one of: a lens mount; a crash stop; or an aperture stop; wherein said microlens and at least a portion of said adjacent structure are formed as a single, unitary substantially monolithic piece, without the need to couple two or more separately-formed structures to provide said piece. ### Claim 42 (depends on 41) An assembly as claimed in claim 41 wherein said adjacent structure includes a part of a surface of said substrate. ### Claim 43 (depends on 41) An assembly as claimed in claim 41 wherein said adjacent structure includes a structure etched from a part of a surface of said substrate. ### Claim 44 (depends on 41) An assembly as claimed in claim 41 wherein said microlens has a sag depth of at least about 100 micrometers and wherein said microlens is etched by an etching process performed in less than about 10 hours. ### Claim 45 (depends on 41) An assembly as claimed in claim 41 wherein said substrate includes a material selected from the group consisting of ZnSe, gallium phosphide or fused silica. ### Claim 46 (depends on 41) An assembly as claimed in claim 41 wherein said microlens is etched by a reactive ion etch. ### Claim 47 (depends on 41) An assembly as claimed in claim 41 further comprising a reflective or opaque coating selectively positioned on at least portions of at least a first surface of said assembly. ### Claim 48 (depends on 41) An assembly as claimed in claim 41 further comprising at least a first diffractive optic pattern positioned on said assembly. ### Claim 49 (depends on 48) An assembly as claimed in claim 48 wherein said diffractive optic is a hologram. ### Claim 50 (depends on 48) An assembly as claimed in claim 48 wherein said diffractive optic is configured to provide dispersion compensation. ### Claim 51 (depends on 41) An assembly as claimed in claim 41 further comprising positioned means for providing at least one of a quarter wave plate functionality, birefringence, or anti-reflective functionality. ### Claim 52 (depends on 41) An assembly as claimed in claim 41 wherein said microlens is configured for use with at least a first wavelength of light and wherein said positioned means comprise sub-wavelength features in a plurality of regions of said wafer. ### Claim 53 (depends on 41) An assembly as claimed in claim 41 wherein surfaces of said lens surfaces are positioned recessed from an adjacent surface region of said substrate. ### Claim 54 (depends on 41) An assembly as claimed in claim 41 wherein said microlens has an index of refraction of at least about 1.4.