| || Growth of High Quality GaAs by MBE
Author : Chand, Naresh
Source : Defence Science Journal ; Vol:39(4) ; 1989 ; pp 335-352
Subject : 548 Crystallography;548.2 Crystal Growth
Keywords : Epitaxial MBE growth
Abstract : This paper reviews the requirements and current practices in the molecular beam epitaxial (MBE) growth of high-quality GaAs. High-quality growth of GaAs means excellent control on the growth process and the excellent surface, structural, electrical and optical properties of the deposited GaAs. Background material is presented about the MBE technique, the MBE system and its initial preparation for growth, molecular-beam source materials, substrate preparation and the growth conditions. The importance of meticulousness at every step is emphasized. Then, to illustrate that the MBE-GaAs has reached a level of perfection, experimental data is presented which shows an excellent control on the growth rate and its lateral uniformity (+ - 0.75 per cent), the presence of very low-level of background impurities (~ low 10/sup 13/cm/sup -3/) and high electron mobilites (meu/sub peak/ ~ 3 X 10 /sup 5/ cm/sup 2/ V/sup -1/ s/sup -1/ at 42 K for n ~ 3 X 10 /sup 13/ cm /sup -3/). In addition, we show that MBE-GaAs is intrinsically free from electron and hole deep traps. Chemical impurities in the impure arsenic source are shown to be the main limiting factors in determining the transport and optical properties and formation of deep centers in MBE-GaAs. Such chemical impurities may, however, originate from other sources as well.