Passivation of deep level defects in molecular beam epitaxial GaAs by hydrogen plasma exposure.
01 January 1986
The effect of hydrogen plasma exposure on the deep level defects present in GaAs grown by molecular beam epitaxy (MBE) has been investigated by deep level transient spectroscopy (DLTS) and by photoluminescence. The three commonly observed defects in MBE grown layers, the M1, M2 and M4 levels, found to be present at a total concentration of 5 x 10(13) cm(-3), are completely passivated by exposure to the hydrogen plasma. At low carrier concentration, in samples where surface recombination is suppressed by a thin Ga(x)Al(1-x)As cap, passivation of these defects increases photoluminescence efficiency, for example, in undoped material (p = 5 x 10(13) cm(-3)), by factors of 30 and 100 at 298K and 77K respectively.