EFFECTIVE TECHNIQUES FOR ULTRA-HIGH PURITY LIQUID-PHASE EPITAXIAL-GROWTH OF GA0.47IN0.53AS

Ultra-high purities are obtained using a two-step method involving baking the In solvent in wet hydrogen prior to the source addition and subsequent solution recycling for several growth stages with baking in dry hydrogen. We obtain the highest purity so far with a carrier concentration as low as 5.8 x 10(13) cm-3, and an electron mobility as high as 132000 cm2/Vs at 77 K for a GaInAs lattice matched to an InP substrate using three subsequent recyclings of the source solution after baking the In in wet hydrogen. The purity obtainable with this technique seems to be restricted by the indium purity, and more seriously by both impurity out-diffusions into solution from the substrate, and from the boat, which absorbs impurities at the preceding growth stage.