US 12,326,541 B1
Index-gradient structures with nanovoided materials and corresponding systems and methods
Andrew John Ouderkirk, Kirkland, WA (US); Katherine Marie Smyth, Seattle, WA (US); and Qi Zhang, Kirkland, WA (US)
Assigned to Meta Platforms Technologies, LLC, Menlo Park, CA (US)
Filed by META PLATFORMS TECHNOLOGIES, LLC, Menlo Park, CA (US)
Filed on Apr. 28, 2022, as Appl. No. 17/731,778.
Application 17/731,778 is a continuation of application No. 16/213,902, filed on Dec. 7, 2018, granted, now 11,340,386.
Int. Cl. C23C 16/46 (2006.01); C23C 16/48 (2006.01); C23C 18/14 (2006.01); G02B 1/111 (2015.01)
CPC G02B 1/111 (2013.01) [C23C 16/463 (2013.01); C23C 16/48 (2013.01); C23C 18/14 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of fabricating an anti-reflective structure comprising a material defining a plurality of nanovoids, the method comprising:
depositing a first fluid on a substrate;
processing the first fluid to form a first region having a first refractive index corresponding to a first concentration of nanovoids per unit volume, the first region comprising a first polymer matrix material defining a first plurality of closed-cell nanovoids;
depositing a second fluid on the first region; and
processing the second fluid to form a second region having a second refractive index corresponding to a second concentration of nanovoids per unit volume, the second region comprising a second polymer matrix material defining a second plurality of closed-cell nanovoids,
wherein the closed-cell nanovoids in at least one of the first region or the second region are defined by another polymer material coating interior regions of the polymer matrix.