DocumentCode
2663545
Title
Comparison of sulfide films formed on copper by surface segregation and wet H2S exposure
Author
Zhang, J.G. ; Zhai, D.Y. ; Zhu, M.D. ; Chen, L.M. ; Vook, R.W. ; Kothari, R.
Author_Institution
Beijing Univ. of Posts & Telecommun., China
fYear
1991
fDate
6-9 Oct. 1991
Firstpage
229
Lastpage
236
Abstract
It is shown that the sulfide films formed in a technical vacuum on copper are composed mainly of Cu/sub 2/O and Cu/sub 2/S, and have a composition slightly different from films formed by an H/sub 2/S exposure. AES (Auger electron spectroscopy) depth profiles and ESCA (electron spectroscopy for chemical analysis) experiments showed that surface segregated sulfide films formed in ultrahigh vacuum as well as those formed in a technical vacuum disappeared on air exposure of approximately 5 to 7 days. At the same time the characteristic oxygen photoemission lines from Cu/sub 2/O and CuO increased significantly. It is concluded that the sulfur was entirely replaced by oxygen and that the resulting free sulfur, which has a high vapor pressure at room temperature, simply evaporated. A similar tendency was observed for the sulfide film formed on wet H/sub 2/S exposure (1.5-2 p.p.m.) after a 7 day air exposure. An AES depth profile showed that part of the sulfide film was buried by oxide and part of it vanished. The polarity effect on thick films formed by wet H/sub 2/S was significant; it decreased with decreasing film thickness. A polarity effect was also found on a sulfur segregated surface formed in technical vacuum; however, it degraded rapidly with time.<>
Keywords
copper; copper compounds; corrosion testing; electrical contacts; hydrogen compounds; 5 to 7 days; AES depth profile; Auger electron spectroscopy; Cu surface; Cu/sub 2/O films; Cu/sub 2/S films; CuO films; OFHC Cu; air exposure; electron spectroscopy for chemical analysis; polarity effect; surface segregation; technical vacuum; ultrahigh vacuum; wet H/sub 2/S exposure; Copper; Heating; Photoelectricity; Rough surfaces; Scanning electron microscopy; Spectroscopy; Surface roughness; Temperature; Thick films; Vacuum technology;
fLanguage
English
Publisher
ieee
Conference_Titel
Electrical Contacts, 1991. Proceedings of the Thirty-Seventh IEEE Holm Conference on
Conference_Location
Chicago, IL, USA
Print_ISBN
0-7803-0231-1
Type
conf
DOI
10.1109/HOLM.1991.170828
Filename
170828
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