Selective area growth by periodic supply molecular beam epitaxy

Selective area growth (SAG) was studied by applying periodic supply epitaxy (PSE) to molecular beam epitaxy (MBE). Different growth conditions and PSE parameters were employed, and their influence on the degree of selectivity will be described in detail. The experimental results of the SAG of GaAs and AlGaAs on GaAs (001) and (111)B substrates patterned with a SiO2 mask will be showed and discussed. The SAG of AlGaAs was found to he very difficult because AlGaAs polycrystalline islands that are formed on the mask require more energy to be decomposed due to the stronger Al-As bonds. Despite the difficulties in SAG by MBE, the PSE technique made it possible to grow selectively smooth epitaxial layers of GaAs and AlGaAs on both kinds of substrates.