US 12,169,359 B2
Manufacture of surface relief structures
Ian Sturland, Filton Bristol (GB); Mark Venables, Filton Bristol (GB); Tracey Hawke, Filton Bristol (GB); Rory Mills, Rochester Kent (GB); and Ian Macken, Rochester Kent (GB)
Assigned to Snap Inc., Santa Monica, CA (US)
Appl. No. 17/753,096
Filed by Snap Inc., Santa Monica, CA (US)
PCT Filed Aug. 20, 2020, PCT No. PCT/GB2020/051997
§ 371(c)(1), (2) Date Feb. 18, 2022,
PCT Pub. No. WO2021/032983, PCT Pub. Date Feb. 25, 2021.
Claims priority of application No. 1911981 (GB), filed on Aug. 21, 2019; and application No. 19275136 (EP), filed on Nov. 28, 2019.
Prior Publication US 2022/0342297 A1, Oct. 27, 2022
Int. Cl. G03F 7/00 (2006.01); B05C 3/02 (2006.01); B05D 1/18 (2006.01); B81C 1/00 (2006.01); G02B 5/18 (2006.01)
CPC G03F 7/001 (2013.01) [B05C 3/02 (2013.01); B05D 1/18 (2013.01); B81C 1/00523 (2013.01); B81C 1/00539 (2013.01); B81C 1/00555 (2013.01); B81C 1/00626 (2013.01); B81C 1/00634 (2013.01); G02B 5/1857 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method of etching a blazed surface relief structure in a substrate, the method comprising:
moving the substrate between a first position and a second position in an etching system, wherein in the first position only a first part of the area to be etched is exposed to an etchant, wherein the etchant is an anisotropic etchant, and in the second position the area to be etched is exposed to the etchant such that the first part of the area to be etched is exposed to the etchant for a longer period of time than at least one other part of the area to be etched, and wherein the movement is defined according to an etching profile, both the movement of the substrate and an orientation of the substrate are relative to a surface of the etchant defined according to the etching profile; and
removing the substrate from the etchant when etching is complete;
wherein the surface relief structure comprises a variable depth etching profile.