GROWTH AND DRY ETCH PROCESSING OF MOMBE GAAS P-N-JUNCTIONS

p-n GaAs junctions grown by metal-organic molecular beam epitaxy (MOMBE) utilizing carbon and tin derived from gaseous sources are demonstrated. The dopants exhibit sharp profiles with no cross-contamination into adjacent layers. Ideality factors of 1.55 were obtained for both n-on-p and p-on-n diodes, with an absence of low-bias recombination current. Simultaneous exposure of both the n- and p-type layers to O2 or H2 discharges produces increases in the respective sheet resistances which are functions of the DC bias on the sample during the plasma exposure and of the exposure time. Significant changes in the ideality factor of an n-on-p junction are only observed for O+ or H+ ion energies above -200 V. Hydrogen passivation effects can be removed by annealing at 400-degrees-C, but high energy (greater-than-or-equal-to 300 eV) O+ ion bombardment causes irreversible damage to the diode.