Growth of GaAs on vicinal Ge surface using low-temperature migration-enhanced epitaxy

Abstract

In this article, we demonstrate the influence of substrate temperature during migration-enhanced epitaxy (MEE) process of GaAs epitaxy on a vicinal surface of Ge (100), 6° offcut towards the (111) plane. It was found that the offcut surface is not the sufficient condition for suppressing the formation of antiphase domains at the GaAs∕Ge interface. Rather, it has to be complemented by low substrate temperature during the MEE process. GaAs grown at 250°C, the lowest temperature among all the samples, exhibits the smoothest surface and best structural and optical qualities, as characterized by atomic force microscopy, cross-sectional transmission electron microscopy, and low-temperature photoluminescence, respectively. At this substrate temperature, As dimers are adsorbed onto the substrate surface more readily with negligible reevaporation, ensuring complete coverage on the Ge surface with double-atomic steps. Complete coverage by As proved to be crucial in preventing the occurrence of inversion boundaries, or at the very least ensure fewer As vacancies that may act as defect centers. Furthermore, low substrate temperature shortens the migration distance of Ga adatoms, minimizing their adsorption into the kinks and step edges, resulting in two-dimensional growth mode instead of step-flow growth mode.

The influence of lattice oxygen on the initial growth behavior of heteroepitaxial Ge layers on single crystalline PrO2(111)∕Si(111) support systems

“…This approach is promising because, in contrast to the large lattice ͑ϳ4.1% ͒ and thermal ͑ϳ110% ͒ mismatch between GaAs and Si, only a minimal lattice mismatch ͑ϳ0.08% ͒ and almost no thermal expansion coefficient difference are reported between GaAs and Ge. 6 It must, however, be pointed out that, to the best of our knowledge, the quality of the up to nowadays available GeOI heterostructures on Si prepared by two simple, subsequent oxide and Ge epi-steps have not yet achieved the level of technological relevance. This is mainly due to the fact that the fundamental physical mechanisms of the interaction between Ge and the buffer dielectric materials ͑i.e., transition and rare earth oxides͒ are only poorly understood at present.…”

Structure and stability of cub‐Pr2O3 films on Si(111) under post deposition annealing conditions

“…High quality praseodymia films are interesting within this field because they can be used as buffer material between Si substrates and Ge layers (germanium-on-insulator technology, GOI). This provides applications of high interest like the cost-effective integration of III-V optoelectronic materials (GaAs) on the Si material platform [1,2]. In addition, the formation of Ge nanodots on top of cubic-Pr 2 O 3 films was studied as a model system for Ge nanocrystal based nonvolatile memory (NVM) cells [3].…”

Structure of oxygen-plasma-treated ultrathin praseodymia films on Si(111)

“…2 For instance, REO films are of potential use to improve the performance and functionality of future semiconductor devices by integrating alternative semiconductor materials into the present Si technology. 3,4 In this regard, single-crystalline REO films are under discussion as highly functional insulating buffer material to form so-called engineered Si wafers. The main research fields are integrated germanium-on-insulator systems aiming to boost the sub-45-nm complementary metal-oxide-semiconductor technologies and further to achieve the cost-effective monolithic integration of III-V optoelectronic materials (GaAs) on the Si wafer platform.…”