US 11,800,702 B2
Method of forming a memory device
Hsu-Yang Wang, Tainan (TW); Ping-Cheng Hsu, Taipei (TW); Shih-Fang Tzou, Tainan (TW); Chin-Lung Lin, Hsinchu (TW); Yi-Hsiu Lee, Chiayi County (TW); Koji Taniguchi, Tainan (TW); Harn-Jiunn Wang, Kaohsiung (TW); and Tsung-Ying Tsai, Kaohsiung (TW)
Assigned to UNITED MICROELECTRONICS CORP., Hsin-Chu (TW); and Fujian Jinhua Integrated Circuit Co., Ltd., Quanzhou (CN)
Filed by UNITED MICROELECTRONICS CORP., Hsin-Chu (TW); and Fujian Jinhua Integrated Circuit Co., Ltd., Quanzhou (CN)
Filed on Mar. 16, 2021, as Appl. No. 17/202,359.
Application 17/202,359 is a division of application No. 16/177,348, filed on Oct. 31, 2018, granted, now 10,985,166.
Claims priority of application No. 201711364213.2 (CN), filed on Dec. 18, 2017.
Prior Publication US 2021/0202492 A1, Jul. 1, 2021
Int. Cl. H01L 27/108 (2006.01); H10B 12/00 (2023.01); H01L 21/308 (2006.01); H01L 21/762 (2006.01)
CPC H10B 12/482 (2023.02) [H01L 21/3086 (2013.01); H01L 21/76224 (2013.01); H10B 12/053 (2023.02); H10B 12/34 (2023.02); H10B 12/485 (2023.02); H10B 12/488 (2023.02)] 11 Claims
OG exemplary drawing
 
1. A method for forming a memory device, comprising:
providing a substrate;
forming an isolation structure in the substrate to define a plurality of active regions in the substrate, the active regions respectively comprising two terminal portions and a central portion between the terminal portions;
forming a plurality of island features on the substrate, wherein in a top view, the island features are separated from each other and each of the island features covers two of the terminals portions respectively belonging to two of the active regions;
performing a first etching process, using the island features as an etching mask to etch the substrate to define a plurality of island structures and a first recessed region between the island structures on the substrate; and
removing the island features to expose the island structures.