Passivation of GaAs by electrochemical sulfur treatments

J. Yota, Veronica Burrows, S. Guha

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations


Simple chemical sulfur treatments of GaAs have been shown to passivate the GaAs surface. These treatments result in lower surface state density, lower surface recombination velocity, and shifting or unpinning of the Fermi level, in addition to improvement in the performance of GaAs devices. Electrochemical sulfur treatment, however, has only recently been explored and pursued as a method of growing anodic surface layers which have good passivating characteristics on semiconductors. In this study, using surface infrared reflection spectroscopy (SIRS), x-ray photoelectron spectroscopy (XPS), and Raman spectroscopy, we have investigated the electrochemical sulfidation of GaAs as a method to produce a GaAs surface that has good electronic properties and is stable chemically and electronically. We have found that anodic treatments with Na2S and (NH4)2S solutions resulted in the removal of the pre-existing oxide of GaAs and in the formation of films comprising sulfur, sodium carbonate, ammonium thiosulfate, and various sulfide and sulfur-oxygen compounds of arsenic. The surface state density of this anodically treated surface was significantly better than that of untreated GaAs. Rinsing the GaAs with water removed the bulk of the film, leaving behind a surface on which only arsenic sulfide was detected. The surface state density after rinsing has degraded slightly, however, but it was still better than that of an untreated GaAs.

Original languageEnglish (US)
Title of host publicationSurface Chemical Cleaning and Passivation for Semiconductor Processing
EditorsGregg S. Higashi, Eugene A. Irene, Tadahiro Ohmi
PublisherPubl by Materials Research Society
Number of pages6
ISBN (Print)1558992138
StatePublished - Dec 1 1993
EventProceedings of the 1993 Spring Meeting of the Materials Research Society - San Francisco, CA, USA
Duration: Apr 13 1993Apr 15 1993

Publication series

NameMaterials Research Society Symposium Proceedings
ISSN (Print)0272-9172


OtherProceedings of the 1993 Spring Meeting of the Materials Research Society
CitySan Francisco, CA, USA

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering


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