Effects of N doping in Ru-Ta alloy barrier on film property and reliability for Cu interconnects

Author

Torazawa, Naoki ; Hinomura, Toru ; Mori, Kenichi ; Koyama, Yuki ; Hirao, Shuji ; Kobori, Etsuyoshi ; Korogi, Hayato ; Maekawa, Kazuyoshi ; Tomita, Kazuo ; Chibahara, Hiroyuki ; Suzumura, Naohito ; Asai, Koyu ; Miyatake, Hiroshi ; Matsumoto, Susumu

Author_Institution

Panasonic Corp., Semicond. Co., Kyoto

fYear

2009

fDate

1-3 June 2009

Firstpage

113

Lastpage

115

Abstract

RuTa(N) film has been prepared by doping N in Ru-Ta alloy and investigated its use as a barrier layer against Cu diffusion in Cu interconnects. It was found that RuTa(N) has a poor barrier property against Cu in the BEOL process, since N in Ru-Ta alloy is desorbed and RuTa(N) is recrystallized by heat treatment. It was also shown that RuTa(N) has inferior reliability due to its poor wettability with Cu compared to RuTa. On the other hand, RuTa has both good barrier property and superior reliability performance. It is possible to apply RuTa single film as a barrier layer for Cu interconnects.

Keywords

alloying additions; copper; diffusion barriers; doping; heat treatment; integrated circuit interconnections; metallic thin films; nitrogen; reliability; ruthenium alloys; tantalum alloys; BEOL process; Cu; Cu interconnects; N doping; Ru-Ta alloy barrier; RuTa:N; desorption; recrystallisation; reliability; wettability; Annealing; Argon; Chemical vapor deposition; Copper alloys; Integrated circuit interconnections; Scanning electron microscopy; Semiconductor device doping; Semiconductor films; Ultra large scale integration; X-ray scattering;

fLanguage

English

Publisher

ieee

Conference_Titel

Interconnect Technology Conference, 2009. IITC 2009. IEEE International

Conference_Location

Sapporo, Hokkaido

Print_ISBN

978-1-4244-4492-2

Electronic_ISBN

978-1-4244-4493-9

Type

conf

DOI

10.1109/IITC.2009.5090356

Filename

5090356