Low temperature oxide desorption in GaAs (111)A substrates

Trabajo presentado al 17th european Molecular Beam Epitaxy Workshop celebrado en Levi (Finlandia) del 10 al 13 de Marzo de 2013.Peer Reviewe

Low temperature oxide desorption in GaAs (111)A substrates

The aim of this work is to study oxide removal processes on GaAs (111) A substrates previous to epitaxial growth. We have studied conventional thermal desorption and processes based on the reduction of surface oxides by deposition of gallium, indium and exposure to atomic hydrogen. We have determined substrate temperatures (Ts) for optimum oxide removal in epi-ready substrates by the different studied processes: Ts = 540 °C for thermal desorption, Ts = 505 °C for indium deposition and Ts = 400 °C for oxide desorption by exposure to atomic hydrogen. All these processes allow for a subsequent good quality epitaxial growth. These results cannot be directly extended to oxide removal in grown samples that have been exposed to air outside the growth chamber. In this case, we have found that only indium deposition and exposure to atomic hydrogen are compatible with regrowth processes.We acknowledge financial support from Spanish MINECO (Grant TEC2011-29120-C05-04), and CAM (Grant S2009ESP-1503). Jesús Herranz acknowledges the JAE program for the funds.Peer Reviewe