US 11,889,678 B2
Method of manufacturing buried word line structure and semiconductor memory thereof
Jian Yang, Hefei (CN)
Assigned to CHANGXIN MEMORY TECHNOLOGIES, INC., Hefei (CN)
Filed by CHANGXIN MEMORY TECHNOLOGIES, INC., Hefei (CN)
Filed on Jul. 30, 2021, as Appl. No. 17/444,139.
Application 17/444,139 is a continuation of application No. PCT/CN2021/086230, filed on Apr. 9, 2021.
Claims priority of application No. 202010396447.0 (CN), filed on May 12, 2020.
Prior Publication US 2021/0358921 A1, Nov. 18, 2021
Int. Cl. H10B 12/00 (2023.01)
CPC H10B 12/053 (2023.02) [H10B 12/34 (2023.02)] 19 Claims
OG exemplary drawing
 
1. A method of manufacturing a buried word line structure, comprising:
providing a semiconductor substrate;
injecting target ions into the semiconductor substrate to form an injected region in the semiconductor substrate;
annealing the semiconductor substrate comprising the injected region to convert the injected region into an insulation region;
forming a word line trench in the insulation region by partially etching the insulation region, a width of the word line trench being less than a width of the insulation region, a height of the word line trench being less than a height of the injected region, and a residual part of the etched insulation region being used as a gate oxide layer of the buried word line structure; and
filling the word line trench with a word line metal to form the buried word line structure.