Ion Beam Mixing in Insulator Substrates

Abstract

AbstractIon beam mixing involving insulator substrates is reviewed with an emphasis on thermochemical considerations. Studies generally have employed the bi-layer geometry for metal/insulator or oxide/oxide combinations. There is little evidence for long-range material transport in crystalline substrates.Recoil mixing has been detected for both metal and oxide films deposited on sapphire and irradiated at room temperature. Agglomeration of non-wetting metal films suggests that surface diffusion is induced by the ion beam. Evidence has been reported for the occurrence of chemical reactions and perhaps thermally-induced migration in amorphous aluminum oxide substrates.Ballistic mixing is also indicated for metal films on SiC, Si3N4 and SiO2. Ion beam-induced reactions have been observed at the interfaces for systems in which the enthalpy of reaction is favorable. Chemical effects in the cascade mixing regime may determine the phases present in the mixed zone after the composition changes caused by ballistic processes.