US 9,812,335 B2
Method of forming fine pattern of semiconductor device
Je-Woo Han, Hwaseong-si (KR); Junho Yoon, Suwon-si (KR); Kyohyeok Kim, Seoul (KR); Dongchan Kim, Seoul (KR); Sungyeon Kim, Jeongeup-si (KR); Jaehong Park, Seongnam-si (KR); Jinyoung Park, Anyang-si (KR); and KyungYub Jeon, Yongin-si (KR)
Assigned to SAMSUNG ELECTRONICS CO., LTD., Suwon-si (KR)
Filed by SAMSUNG ELECTRONICS CO., LTD., Suwon-si (KR)
Filed on Mar. 10, 2016, as Appl. No. 15/66,492.
Claims priority of application No. 10-2015-0047075 (KR), filed on Apr. 2, 2015.
Prior Publication US 2016/0293445 A1, Oct. 6, 2016
Int. Cl. H01L 21/311 (2006.01); H01L 21/768 (2006.01)
CPC H01L 21/31144 (2013.01) [H01L 21/31116 (2013.01); H01L 21/76816 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method of fabricating a semiconductor device, the method comprising:
forming an etch target layer on a substrate;
forming a mask pattern on the etch target layer;
performing a first etch process to etch the etch target layer and form a first sub-trench, the mask pattern and a first sidewall pattern formed on a sidewall of the mask pattern being used as a first etch mask in the first etch process; and
performing a second etch process to further etch the etch target layer under the first sub-trench and form a second sub-trench, the mask pattern and a second sidewall pattern formed on the sidewall of the mask pattern being used as a second etch mask in the second etch process,
wherein the second etch process is performed to change a first angle of a first outer sidewall of the first sidewall pattern with respect to a top surface of the substrate to form a second outer sidewall of the second sidewall pattern having a second angle different from the first angle with respect to the top surface of the substrate.