US 11,935,748 B2
Fabricating a device using a multilayer stack
Anthony Edward Megrant, Goleta, CA (US)
Assigned to Google LLC, Mountain View, CA (US)
Appl. No. 16/640,411
Filed by Google LLC, Mountain View, CA (US)
PCT Filed Dec. 7, 2017, PCT No. PCT/US2017/065018
§ 371(c)(1), (2) Date Feb. 20, 2020,
PCT Pub. No. WO2019/045763, PCT Pub. Date Mar. 7, 2019.
Claims priority of provisional application 62/552,743, filed on Aug. 31, 2017.
Prior Publication US 2020/0365397 A1, Nov. 19, 2020
Int. Cl. G03F 7/09 (2006.01); H01L 21/027 (2006.01); H01L 21/3213 (2006.01)
CPC H01L 21/0274 (2013.01) [G03F 7/094 (2013.01); H01L 21/32139 (2013.01)] 14 Claims
 
1. A method of fabricating a device, comprising:
forming a multilayer stack on a substrate which has a principal surface, the multilayer stack comprising:
a first layer formed on the principal surface of the substrate, wherein the first layer is a first polymeric material;
a supporting layer formed on the first layer, wherein the supporting layer is a second polymeric material; and
a photoresist layer formed on the supporting layer;
patterning the multilayer stack to form at least one opening such that the photoresist layer is undercut by the supporting layer and the supporting layer is overcut by the first layer, wherein patterning the multilayer stack comprises simultaneously developing the photoresist layer and the supporting layer using a developer, wherein a portion of the supporting layer corresponding to the at least one opening is soluble in the developer, wherein the developer is an alkaline developer; and
anisotropically dry etching the substrate.