Impurity breakdown in GaAs samples grown by molecular beam Epitaxy

• Autor(a) principal: Rubinger,R.M.
• Data de Publicação: 1999
• Outros Autores: Oliveira,A.G. de, Ribeiro,G.M., Bezerra,J.C., Silva,C.M., Rodrigues,W.N., Moreira,M.V.B.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Brazilian Journal of Physics
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-97331999000400038

In this work we present studies for the behavior of impurity breakdown of two GaAs samples grown by Molecular Beam Epitaxy at 200°C and 300°C. We vary the temperature and the illumination intensity. For the sample grown at 200°C, the transport mechanism after the breakdown is of the same type of the main free carriers at low electric fields. Below 100K, a clear dependence of the threshold electric field with temperature was observed. The sample grown at 300°C shows a breakdown due to an acceptor level at 41meV from the valence band. The threshold electric field increases with illumination due to the generation of free electrons by deep levels. A similar behavior was also observed for a Cr doped GaAs sample.