US 12,094,709 B2
Plasma treatment process to densify oxide layers
Jung Chan Lee, San Jose, CA (US); Mun Kyu Park, San Jose, CA (US); Jun Lee, Andover, MA (US); Euhngi Lee, Santa Clara, CA (US); Kyu-Ha Shim, Gloucester, MA (US); Deven Matthew Raj Mittal, Santa Clara, CA (US); Sungho Jo, Chestnut Hill, MA (US); Timothy Miller, Santa Clara, CA (US); Jingmei Liang, San Jose, CA (US); Praket Prakash Jha, San Jose, CA (US); and Sanjay G. Kamath, Fremont, CA (US)
Assigned to APPLIED MATERIALS, INC., Santa Clara, CA (US)
Filed by Applied Materials, Inc., Santa Clara, CA (US)
Filed on Jul. 30, 2021, as Appl. No. 17/390,151.
Prior Publication US 2023/0030436 A1, Feb. 2, 2023
Int. Cl. H01L 21/02 (2006.01)
CPC H01L 21/0234 (2013.01) [H01L 21/02164 (2013.01); H01L 21/0223 (2013.01); H01L 21/02271 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for processing a substrate, comprising:
forming an oxide layer comprising silicon oxide and having an initial wet etch rate (WER) over features disposed on the substrate, wherein the initial WER is determined with an etchant having a concentration;
exposing the oxide layer to a first plasma treatment to produce a treated oxide layer while maintaining the substrate at a first temperature of less than 600° C., wherein the first plasma treatment comprises:
generating a first plasma by a first RF source; and
directing the first plasma to the oxide layer by a DC bias; and then
exposing the treated oxide layer to a second plasma treatment to produce a densified oxide layer while maintaining the substrate at a second temperature of less than 600° C., wherein the densified oxide layer has a final WER of less than one-half of the initial WER, wherein the final WER is determined with the etchant having the concentration, wherein the oxide layer comprising silicon oxide has a normalized wet etch rate ratio (WERR) of 1 and the densified oxide layer has a final WERR of about 0.1 to about 0.48, and wherein the second plasma treatment comprises:
generating a second plasma by a top RF source and a side RF source; and
directing the second plasma to the treated oxide layer without a bias.