ISSN:
1063-7826
Source:
Springer Online Journal Archives 1860-2000
Topics:
Electrical Engineering, Measurement and Control Technology
,
Physics
Notes:
Abstract Transmission electron microscopy is used to study the microstructure of indium δ layers in GaAs(001) grown by molecular beam epitaxy at low temperature (200 °C). This material, referred to as LT-GaAs, contains a high concentration (≈1020 cm−3) of point defects. It is established that when the material is δ-doped with indium to levels equivalent to 0.5 or 1 monolayer (ML), the roughness of the growth surface leads to the formation of InAs islands with characteristic lateral dimensions 〈10 nm, which are distributed primarily within four adjacent atomic layers, i.e., the thickness of the indium-containing layer is 1.12 nm. Subsequent annealing, even at relatively low temperatures, leads to significant broadening of the indium-containing layers due to the interdiffusion of In and Ga, which is enhanced by the presence of a high concentration of point defects, particularly V Ga, in LT-GaAs. By measuring the thickness of indium-containing layers annealed at various temperatures, the interdiffusion coefficient is determined to be D In-Ga=5.1×10−12 exp(−1.08 eV/kT) cm2/s, which is more than an order of magnitude larger than D In-Ga for stoichiometric GaAs at 700 °C.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1134/1.1187483
