Electrochemical sulfur treatments of GaAs using Na2S and (NH4)2S solutions: A surface chemical study

J. Yota, Veronica Burrows

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


Chemical sulfur treatments of GaAs have been shown to improve the GaAs surface electronic properties. 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 devices. However, there is still considerable controversy regarding the chemical nature of the surface film which results from this chemical sulfidation. It has been shown that this film is not stable chemically and electronically. The improved surface electronic properties decay with time and are sensitive to the chemical environment of the material. In this study, using surface infrared reflection spectroscopy (SIRS) and x-ray photoelectron spectroscopy (XPS), we have investigated the electrochemical sulfidation of GaAs as a possible new method to produce a GaAs surface that is stable chemically and electronically. We have found that anodic treatments with Na2S and (NH4)2S solutions result in the removal of the pre-existing oxide of GaAs and the formation of films comprising sulfur, sodium carbonate, ammonium thiosulfate, and sulfide and sulfur-oxygen compounds of arsenic. Rinsing the GaAs with water removes the bulk of the film, leaving behind a surface on which only arsenic sulfide was detected.

Original languageEnglish (US)
Title of host publicationChemical Perspectives of Microelectronic Materials III
PublisherPubl by Materials Research Society
Number of pages6
ISBN (Print)1558991778
StatePublished - Jan 1 1993
EventProceedings of the 3rd Biennial Meeting of Chemical Perspectives of Microelectronic Materials - Boston, MA, USA
Duration: Nov 30 1992Dec 3 1992

Publication series

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


OtherProceedings of the 3rd Biennial Meeting of Chemical Perspectives of Microelectronic Materials
CityBoston, MA, USA

ASJC Scopus subject areas

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


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