Thermal Cleaning of InSb Surfaces in an Ultrahigh Vacuum

Abstract

In and Sb surfaces of (111) normalInSb crystals were analyzed by Auger electron spectroscopy (AES) before, during, and after heating them in an ultrahigh vacuum system. Heating the samples to 450°C resulted in stoichiometric and oxygen‐free surfaces. Sulfur due to chemical precleaning is removed at 470°C. Further, if the initial carbon concentration is low enough (< 10% surface coverage), then it can be almost totally removed by thermal cleaning at 450°C.

Preparation of InSb substrates for molecular beam epitaxy

“…[3][4][5][6] The growth and subsequent removal of native oxides has proven to be the most successful method for cleaning Si and GaAs substrates for MBE work. 12,13 ͑iii͒ While the other commonly used in situ cleaning method, i.e., the cyclic process of ion bombardment followed by annealing, is very effective in the removal of active contaminants such as oxygen and carbon, it is well known that In droplets can be formed due to preferential sputtering. When the same approach is used for the preparation of InSb substrates some difficulties arise: ͑i͒ While many chemical etchants have been used, none of them seems to be satisfactory.…”

“…When the same approach is used for the preparation of InSb substrates some difficulties arise: ͑i͒ While many chemical etchants have been used, none of them seems to be satisfactory. 12,16,17 Recently, hydrogen plasma has also been used for in situ reduction of the InSb native oxide. In some cases, surface roughening have also been observed in the etched surfaces.…”

Oxide Removal and Selective Etching of In from InSb(100) with TiCl4

“…These results established a 550–600 K cutoff temperature for vacuum annealing InSb(100) covered by native oxide. Complete oxide desorption from single-crystal InSb(100) and InSb(111) surfaces were reported at 653 and 723 K, respectively. The lower desorption temperature observed for native oxide on an epitaxially grown InSb(100) surface is likely due to differences in surface morphology induced by the large lattice mismatch with the GaAs substrate.…”