Molecular Beam Epitaxy of III–V Compounds

An investigation into silicon doping of MBE (100) GaAs

“…The best MBE GaAs : Si so far obtained has a compensation ratio of N 1.5 (Ploog 1980, Shimanoe et al 1979 compared to the ratio of 2 for the layers in this paper. This is a fairly small difference in measured electrical properties and consequently any inaccuracies associated with the measuring techniques are important.…”

“…Some recent work by Chai (1980) has, however, demonstrated that good quality GaAs:Si material can be obtained for growth rates up to 5.3 pm h-l, although the growth temperature used (580°C) was in excess of that used for the 4 pm h-1 growth in the present work (550 "C). Although extrapolation of the curves of Rode and Knight (1971) indicates that the highest doped epilayer (n=7 x 1018 cm-3) had a compensation ratio of 2 this is probably an overestimate because such a procedure neglects the effects of degeneracy (Ploog 1980). It appears therefore that the best GaAs:Si produced in this study was for n in the range lO18-lO19 cm3 and this material was as good as any reported in the literature (Ploog 1980, Chai 1980.…”

“…Although extrapolation of the curves of Rode and Knight (1971) indicates that the highest doped epilayer (n=7 x 1018 cm-3) had a compensation ratio of 2 this is probably an overestimate because such a procedure neglects the effects of degeneracy (Ploog 1980). It appears therefore that the best GaAs:Si produced in this study was for n in the range lO18-lO19 cm3 and this material was as good as any reported in the literature (Ploog 1980, Chai 1980.…”

“…Despite the rapid development of the MBE technique it is interesting to note that the fundamental requirement of the n-type doping of GaAs still remains an impediment to its progression into an established material and device fabrication technology. A number of donor impurities have been used with varying degrees of success, these include: Si (Cho and Hayashi 1971a, Calawa 1978, Chai 1980; Ge (Cho and Hayashi 1971b, Cho 1975, Wood et aZ 1979; Sn (Ploog andFischer 1978, Wood andJoyce 1978); PbS and PbSe and SnTe (Collins 1979). Sn is the most widely used n-type dopant giving a very low level of compensation when compared with Sn-doped bulk material and theoretical predictions of electron transport properties.…”

Semiconductor heterostructure studies using emerging technologies

“…Semiconductor heterostructures have become the most important systems for solid-state physics and for electronics devices since evolutional crystal growth techniques, like molecular beam epitaxy (MBE) [1,2], succeeded in growing high-quality semiconductor crystals. The combination of different but lattice-matched semiconductors makes bandgap engineering possible, and a quantum well structure has provided an ideal stage to study characteristics of a two-dimensional (2D) system.…”