US 12,077,851 B2
Creation of distributed voids in thin films
Terry Bluck, Santa Clara, CA (US); and Samuel D. Harkness, IV, Albany, CA (US)
Assigned to INTEVAC, INC., Santa Clara, CA (US)
Filed by INTEVAC, INC., Santa Clara, CA (US)
Filed on May 3, 2021, as Appl. No. 17/306,054.
Claims priority of provisional application 62/704,317, filed on May 4, 2020.
Prior Publication US 2021/0355579 A1, Nov. 18, 2021
Int. Cl. C23C 14/58 (2006.01); C03C 17/34 (2006.01); C23C 14/04 (2006.01); H04M 1/02 (2006.01)
CPC C23C 14/5873 (2013.01) [C03C 17/3411 (2013.01); C23C 14/042 (2013.01); H04M 1/0283 (2013.01); C03C 2217/425 (2013.01); C03C 2217/45 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A method for forming on a substrate a layer of thin film having a plurality of voids, comprising:
dispersing on a surface of the substrate a plurality of particles made of a sublimable material and having a diameter no larger than 1000 μm;
forming a thin film layer over the surface of the substrate to a thickness that covers the particles;
etching back the thin film layer to expose the particles at least partially; and,
sublimating the particles to thereby create voids within the thin film layer;
wherein the dispersing comprises suspending the particles in a vaporizable liquid and spreading the liquid over the surface, and thereafter evaporating the liquid.