Improvements of electrical and optical properties of GaAs by substrate bias application during electron-cyclotron-resonance plasma-excited molecular beam epitaxy

Abstract

Electrical and optical properties of GaAs layers are improved by applying substrate bias during electron-cyclotron-resonance plasma-excited molecular beam epitaxy (ECR-MBE). The highest mobility obtained without substrate bias is 4500 cm2 V−1 s−1. By applying positive bias, the mobility of the grown layer is increased to as high as 6800 cm2 V−1 s−1. Intense photoluminescence spectra comparable to that of a high quality MBE-grown layer are also observed. The suppression of high-energy ion impingement on the growing surface plays an important role in obtaining high quality crystal.