Mechanism of via etch striation and its impact on contact resistance & breakdown voltage in 65nm cu low-k interconnects

Author

Sun, Wu ; Shen, Man-Hua ; Wang, Xin-Peng ; Zhang, Hai-Yang ; Yin, Xiao-Ming ; Chang, Shih-Mou

Author_Institution

Semicond. Manuf. Int. Corp., Beijing, China

fYear

2008

fDate

20-23 Oct. 2008

Firstpage

1235

Lastpage

1237

Abstract

The mechanism of two kinds of via etch striation (type I and type II) has been investigated to improve contact resistance (Rc) uniformity and solve breakdown voltage (VBD) issue in 65 nm Cu low-k interconnects. Heavy etching polymer deposition on the sidewall of capping layer and rapid photo-resist (PR) consumption on PR shoulder are two main resources to result in via etch striation. The effects of both via etch striations on Rc and VBD can be decoupled. Type I striation related to barc open (BO) step leads to worse Rc uniformity while type II striation formed in main etch (ME) and over-etch (OE) step degrades VBD performance.

Keywords

contact resistance; copper; etching; integrated circuit interconnections; Cu; breakdown voltage; capping layer; contact resistance; etching polymer deposition; low-k interconnects; rapid photoresist consumption; size 65 nm; via etch striation; CMOS logic circuits; Chemicals; Contact resistance; Degradation; Dielectrics; Dry etching; Plasma applications; Polymers; Semiconductor device manufacture; Sun;

fLanguage

English

Publisher

ieee

Conference_Titel

Solid-State and Integrated-Circuit Technology, 2008. ICSICT 2008. 9th International Conference on

Conference_Location

Beijing

Print_ISBN

978-1-4244-2185-5

Electronic_ISBN

978-1-4244-2186-2

Type

conf

DOI

10.1109/ICSICT.2008.4734771

Filename

4734771