US 11,948,975 B2
Semiconductor device and method for fabricating the same
Chih-Kai Hsu, Tainan (TW); Ssu-I Fu, Kaohsiung (TW); Yu-Hsiang Hung, Tainan (TW); Wei-Chi Cheng, Kaohsiung (TW); and Jyh-Shyang Jenq, Pingtung County (TW)
Assigned to UNITED MICROELECTRONICS CORP., Hsin-Chu (TW)
Filed by UNITED MICROELECTRONICS CORP., Hsin-Chu (TW)
Filed on Oct. 24, 2021, as Appl. No. 17/509,061.
Application 17/509,061 is a division of application No. 16/703,780, filed on Dec. 4, 2019, granted, now 11,189,695.
Application 15/983,077 is a division of application No. 15/259,060, filed on Sep. 8, 2016, granted, now 10,008,569, issued on Jun. 26, 2018.
Application 16/703,780 is a continuation of application No. 15/983,077, filed on May 17, 2018, granted, now 10,541,304, issued on Jan. 21, 2020.
Claims priority of application No. 105125383 (TW), filed on Aug. 10, 2016.
Prior Publication US 2022/0045170 A1, Feb. 10, 2022
Int. Cl. H01L 29/08 (2006.01); H01L 21/8238 (2006.01); H01L 27/092 (2006.01); H01L 29/423 (2006.01); H01L 29/66 (2006.01); H01L 29/78 (2006.01)
CPC H01L 29/0847 (2013.01) [H01L 21/823821 (2013.01); H01L 27/0924 (2013.01); H01L 29/42356 (2013.01); H01L 29/42368 (2013.01); H01L 29/66545 (2013.01); H01L 29/66636 (2013.01); H01L 29/66795 (2013.01); H01L 29/78 (2013.01); H01L 29/7833 (2013.01); H01L 29/7848 (2013.01); H01L 29/785 (2013.01); H01L 29/665 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method for fabricating semiconductor device, comprising:
forming a gate structure on a substrate;
forming a spacer around the gate structure;
forming a contact etch stop layer (CESL) directly contacting the spacer;
forming a buffer layer adjacent to the gate structure, wherein the buffer layer comprises a crescent moon shape and the buffer layer comprises an inner curve, an outer curve, and a planar surface connecting the inner curve and an outer curve along a top surface of the substrate, wherein the planar surface directly contacts the outer curve on an outer sidewall of the spacer;
forming an epitaxial layer on the buffer layer; and
forming a cap layer directly contacting a top surface of the epitaxial layer and between and directly contacting the CESL and the buffer layer, wherein the cap layer and the spacer are made of different materials.