US 12,087,572 B2
Etch stop layer
Bart J. van Schravendijk, Palo Alto, CA (US); Soumana Hamma, Tigard, OR (US); Kai-Lin Ou, Tualatin, OR (US); Ming Li, West Linn, OR (US); and Malay Milan Samantaray, Beaverton, OR (US)
Assigned to Lam Research Corporation, Fremont, CA (US)
Appl. No. 17/598,830
Filed by Lam Research Corporation, Fremont, CA (US)
PCT Filed Mar. 26, 2020, PCT No. PCT/US2020/025004
§ 371(c)(1), (2) Date Sep. 27, 2021,
PCT Pub. No. WO2020/198502, PCT Pub. Date Oct. 1, 2020.
Claims priority of provisional application 62/825,632, filed on Mar. 28, 2019.
Prior Publication US 2022/0181141 A1, Jun. 9, 2022
Int. Cl. H01L 21/02 (2006.01); H01L 21/311 (2006.01); H01L 27/088 (2006.01); H01L 27/1157 (2017.01); H10B 43/20 (2023.01); H10B 43/35 (2023.01)
CPC H01L 21/0217 (2013.01) [H01L 21/02164 (2013.01); H01L 21/02211 (2013.01); H01L 21/02274 (2013.01); H01L 21/0234 (2013.01); H01L 21/31111 (2013.01); H01L 27/088 (2013.01); H10B 43/20 (2023.02); H10B 43/35 (2023.02)] 20 Claims
OG exemplary drawing
 
1. A method comprising:
providing a substrate having alternating oxide layers and nitride layers arranged in a staircase pattern comprising exposed horizontal nitride surfaces and exposed oxide and nitride sidewall surfaces;
depositing a silicon nitride (SiN) layer over the alternating oxide and nitride layers by a plasma enhanced chemical vapor deposition (PECVD) process using a plasma generated from a process gas comprising a silicon-containing precursor; and
treating the SiN layer to selectively densify the SiN layer deposited on the exposed horizontal nitride surfaces wherein the SiN layer comprises a first sub-layer disposed between two second sub-layers each having a higher wet etch rate (WER) than the first sub-layer.