Beryllium ion implants in GaAs annealed at 900~ for 30 rain with a Si3N4 encapsulant have been shown to form p-n junctions with lateral diffusion between 0.5 and 1.0 ~m, junction depth of 0.7 ~m, and implant activation rate of -100%. SiO2 and phosphosilicate glass encapsulants yield similar values of lateral diffusion, junction depth, and activation rate, but are shown to induce near-surface degradation effects manifested by a reduced carrier concentration within 1.0 ~m of the surface in unimplanted annealed material and to produce anomalously high breakdown voltages and high leakage currents in Beimplanted junctions.) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 130.15.241.167 Downloaded on 2015-03-09 to IP ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 130.15.241.167 Downloaded on 2015-03-09 to IP