High quality of 830 nm material grown by solid source molecular beam epitaxy for laser device printing applications

摘要

Molecular beam epitaxy (MBE) has been employed almost entirely for the growth of arsenic compounds due to the lack of a suitable suitable solid phosphorous source. Advanced phosphide epitaxy has only been performed by metal organic chemical vapor deposition and phosphide based gas-source MBE. Solid source MBE (SSMBE), however, is capable of growing GaInAsP and AlGaInP layer structures without using toxic gases as source material. The key of SSMBE in producing high quality phosphides is a valved cracker cell for elemental phosphorus and arsenic, as well as the optimization of growth conditions such as growth temperature, P cracking zone temperature, P/As ratio, ΔT between inner and outer heaters, and doping profiles. The 830 nm material was grown in GEN Ⅲ reactor on 2 in. GaAs wafers doped with Si. Substrate growth temperature by a pyrometer was 500℃, the cracker temperature was kept at 850℃, and ΔT at 12℃. To verify the material quality, wafers were processed to make lasers with different cavity lengths and 56 μm emitter widths. Internal quantum efficiency (η_i) of 95.5% and internal optical losses (α_i) of 0.47 cm~(-1) at 25℃ were obtained. Devices were burn in for more than 5000 h at cw mode, indicating high reliability.