US 11,990,331 B2
Method for forming silicon dioxide film and method for forming metal gate
Jingwen Lu, Hefei (CN); Wei Feng, Hefei (CN); and Bingyu Zhu, Hefei (CN)
Assigned to Changxin Memory Technologies, Inc., Hefei (CN)
Filed by CHANGXIN MEMORY TECHNOLOGIES, INC., Hefei (CN)
Filed on Aug. 10, 2021, as Appl. No. 17/398,075.
Application 17/398,075 is a continuation of application No. PCT/CN2021/095747, filed on May 25, 2021.
Claims priority of application No. 202010545225.0 (CN), filed on Jun. 15, 2020.
Prior Publication US 2021/0391169 A1, Dec. 16, 2021
Int. Cl. H01L 21/02 (2006.01); H01L 21/324 (2006.01)
CPC H01L 21/02164 (2013.01) [H01L 21/02332 (2013.01); H01L 21/02334 (2013.01); H01L 21/324 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method for forming a silicon dioxide film, comprising:
providing a semiconductor substrate;
forming a silicon dioxide layer on the semiconductor substrate;
performing a nitrogen treatment to the silicon dioxide layer, such that a first portion of the silicon dioxide layer occupying a portion of a thickness of the silicon dioxide layer and disposed away from the semiconductor substrate is converted into a mixed layer of silicon nitride and silicon oxynitride, and a remaining portion of the silicon dioxide layer in contact with the semiconductor substrate is kept; and
removing the mixed layer such that the remaining portion of the silicon dioxide layer forms a silicon dioxide film on the semiconductor substrate.