ION-BEAM-INDUCED EPITAXIAL REGROWTH AND LAYER-BY-LAYER AMORPHIZATION OF COMPOUND SEMICONDUCTORS DURING MEV ION-IMPLANTATION

Ion beam induced epitaxial crystallization (IBIEC) during irradiation with high energy ions is investigated in preamorphized InP, GaP and In As under different conditions of temperature and dose rate. The maximu m thicknesses of the layers crystallized are 170 nm (InAs), 120 nm (In P) and 70 nm (GaP), showing that the extent of single-crystalline regr owth is much greater than that achieved by thermal crystallization. Tw inned regrowth typical for thermal crystallization is suppressed by io n irradiation, even at temperatures where thermal crystallization proc eeds. The maximum thickness of the IBIEC layer cannot be increased by applying both higher doses and/or higher implantation temperatures. Th is result is explained by the fact that IBIEC is ''blocked'' by ion in duced random nucleation and growth of crystallites within the amorphou s layers. Interfacial amorphization induced by ion beams (IBIIA) is pr oved in InAs. The transition from crystallization to amorphization due to a decrease in the temperature, an increase in the dose rate or an increase in the nuclear energy deposition is in good agreement with th e results for Si and Ge. Critical temperatures for this transition in the considered compound semiconductors are estimated, respectively.