US 12,224,323 B2
Fabrication method of buried wordline structure
Yong Lu, Hefei (CN); and Hongkun Shen, Hefei (CN)
Assigned to CHANGXIN MEMORY TECHNOLOGIES, INC., Hefei (CN)
Filed by CHANGXIN MEMORY TECHNOLOGIES, INC., Hefei (CN)
Filed on Aug. 21, 2021, as Appl. No. 17/445,595.
Application 17/445,595 is a continuation of application No. PCT/CN2021/096669, filed on May 28, 2021.
Claims priority of application No. 202010410658.5 (CN), filed on May 15, 2020.
Prior Publication US 2022/0037478 A1, Feb. 3, 2022
Int. Cl. H01L 29/40 (2006.01); G11C 5/06 (2006.01); H01L 21/762 (2006.01); H01L 29/423 (2006.01); H10B 12/00 (2023.01)
CPC H01L 29/401 (2013.01) [G11C 5/063 (2013.01); H01L 21/76232 (2013.01); H01L 29/4236 (2013.01); H01L 29/42364 (2013.01); H10B 12/488 (2023.02)] 15 Claims
OG exemplary drawing
 
1. A fabrication method for a buried wordline structure, comprising:
providing a first trench in a semiconductor substrate, wherein the first trench has a tip on its bottom;
performing epitaxial growth on the semiconductor substrate within the first trench to reduce the depth of the tip on the bottom of the first trench; and
forming a gate dielectric layer on an inner wall of the first trench and filling a gate conductive layer within the first trench to form the buried wordline structure.