US 11,720,016 B2
Freeform optical substrates in waveguide displays
David Sell, Santa Clara, CA (US); and Samarth Bhargava, Saratoga, CA (US)
Assigned to Applied Materials, Inc., Santa Clara, CA (US)
Filed by Applied Materials, Inc., Santa Clara, CA (US)
Filed on May 10, 2021, as Appl. No. 17/315,613.
Prior Publication US 2022/0357654 A1, Nov. 10, 2022
Int. Cl. G03F 7/00 (2006.01); G02B 25/00 (2006.01)
CPC G03F 7/0005 (2013.01) [G02B 25/001 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method, comprising:
measuring a base substrate thickness distribution across a base substrate;
determining a target thickness change, the target thickness change determined by subtracting the base substrate thickness distribution from a target thickness distribution, the target thickness distribution corresponding to a thickness across one or more eyepiece areas of a substrate to be formed; and
forming a substrate having the target thickness distribution at the one or more eyepiece areas, the forming of the substrate having the target thickness distribution comprising:
disposing a resist over the base substrate and developing the resist utilizing a lithography process to form a gray-tone distribution having a thickness distribution corresponding to the target thickness distribution; or
disposing a resist over the base substrate with an inkjet printing process, the resist having a thickness distribution corresponding to the target thickness distribution and performing a transfer etch into the substrate, the transfer etch forming the target thickness distribution in the substrate.