The study of overlay mark in self aligned double patterning and solution

Author

Shuxin Yao ; Xianguo Dong ; Wei Yuan ; Hongmei Hu ; Yifei Lu ; Shaohai Zeng ; ChunYan Yi ; Ming Li ; Zhengkai Yang ; Wuping Wang ; Zhifeng Gan ; Liang Zhang ; Ermin Chong ; Zhibiao Mao ; Yu Zhang

Author_Institution

Shanghai IC Res. & Dev. Center, Shanghai Huali Microelectron. Corp., Shanghai, China

fYear

2015

Firstpage

1

Lastpage

3

Abstract

Double patterning technology (DPT) has matured as the lithography approach to bridge the gap between ArF water-based immersion lithography and EUV (extreme ultra violet). The adoption of the SADP (self-aligned double patterning) technology relaxes the overlay accuracy requirement compared to LELE (Litho-Etch-Litho-Etch) scheme, especially for flash product. But the traditional BiB(Bar-in-Bar)overlay marks formed by the core mask has been altered, hence the overlay mark recognition could be challenging for the subsequent process layers. This paper will study the overlay mark target design for metrology and will point out the effective solution during fin formation by SADP technology. The result revealed the segmented overlay mark is better than normal overlay mark as for both image contrast and recognition accuracy aspect.

Keywords

immersion lithography; ultraviolet lithography; EUV; extreme ultra violet; fin formation; image contrast; immersion lithography; overlay mark; recognition accuracy aspect; self aligned double patterning technology; Adaptive optics; Coatings; Lithography; Metrology; Optical films; Optical imaging; Scanning electron microscopy;

fLanguage

English

Publisher

ieee

Conference_Titel

Semiconductor Technology International Conference (CSTIC), 2015 China

ISSN

2158-2297

Type

conf

DOI

10.1109/CSTIC.2015.7153355

Filename

7153355