A study of the background carrier concentration of InGaAs grown by hydride VPE

InGaAs has been grown in a hydride VPE reactor using hydrogen chloride obtained by cracking arsenic trichloride in hydrogen. It is shown that this is not sufficient to reduce the background carrier concentration below the 1015 cm-3 range. The observed level is shown to increase with increasing mole fraction of arsine under conditions of constant growth rate indicating that the arsine source is a predominant factor in background carrier concentration. An inverse proportionality between carrier concentration and growth rate is also observed and a model is presented which accounts for this relationship. This model further supports the conclusion that the arsine source is the main factor determining the level of unintentional doping of the InGaAs grown