Experimental test of the transition layer model of atomic layer epitaxy

Abstract

Thermal desorption experiments concerning Te deposits on GaAs (100) surfaces have been performed using quadrupole mass spectrometry. The results give evidence that near the GaAs surface two regions of different Te adsorption can be distinguished. The first region nearest to the substrate surface consists of Te adparticles, which are chemisorbed to the substrate reevaporating at temperatures above 510–520 °C. The adparticles of the second physisorbed region begin to desorb at 350–360 °C, which is still considerably higher than the desorption temperature of the bulk Te deposits. The approximate thicknesses of these two regions are 1–2 monolayers and 3–10 monolayers of Te, respectively.