The primary surface morphology, oval defects, of MBE-grown Be-doped AlGaAs layers has been studied using two different As partial pressure control methods, i.e., thermocouple (TC) and nude ion gauge (NIG) methods. The observed defect density has been studied as a systematic function of growth parameters, including doping concentration, substrate temperature, growth rate, epilayer thickness, and As partial pressure. The protrusion-induced oval defects were formed during MBE growth. The primary origin of the oval defects generated in our system is believed to be the presence of non-volatile III2O3 oxide. However, an oval defect density less than 600 cm-2 has been obtained through optimization of the growth parameters, and after paying careful attention to substrate preparation and vacuum conditions.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Inorganic Chemistry
- Materials Chemistry