Vol. 39, Issue 4, pp. 787-797

Vol. 39 Issue 4 pp. 787-797

(100) GaAs surface treatment prior to contact metal deposition in AlGaAs/GaAs quantum cascade laser processing

Ewa Papis, Anna Baranska, Piotr Karbownik, Anna Szerling, Anna Wojcik-Jedlinska, Maciej Bugajski, Witold Rzodkiewicz, Jacek Szade, Andrzej Wawro

Keywords

GaAs, surface treatment, sputter etching

Abstract

The effects of HCl-based chemical and Ar+ sputter etching treatment on (100) GaAs surface properties with the aim to develop the procedure of surface preparation before metal deposition have been investigated. Variable angle spectroscopic ellipsometry, X-ray photoelectron spectroscopy, atomic force microscopy and photoluminescence have been used to study the surface characterization. We show that combining chemical etching in 5% HCl with Ar+ sputter etching gives the best results for surface cleaning prior to metal deposition. The application of this two-step treatment allows to obtain Ni/AuGe/Ni/Au ohmic contact with rc = 2×10–6 Ωcm2 with excellent adhesion and long-term thermal stability.

Vol. 39
Issue 4
pp. 787-797

3.13 MB
OPTICA APPLICATA - a quarterly of the Wrocław University of Science and Technology, Faculty of Fundamental Problems of Technology