MOVPE growth of Si-doped GaAs and Al_xGa_(1-x)As using tertiarybutylarsine (TBA) in pure N_2 ambient

摘要

The effects of Si-doping on the growth of GaAs and Al_xGa_(1-x)As alloy in MOVPE system using tertiarybutylarsine (TBA) in a pure N_2 ambient have been studied. For Si-doped GaAs, the electron carrier concentration increases to a maximum of 3.4 * 10~(18) cm~(-3) with the increase of SiH4 flow rate, and then decreases with any further increase of SiH4 flow rate. For Al_xGa_(1-x)As with Al concentration x=0.52 the electron carrier concentration reached to a maximum of 3.3 * 10~(17) cm~(-3). The AlxGa1-xAs alloy grown in a nitrogen ambient has a lower Al concentration than the one that grown normally in an H2 ambient. It has also been found that the Al content of the alloy decreases with an increase of silane concentration for a constant group V/III ratio during the MOVPE growth.