Growth of InN for ohmic contact formation by electron cyclotron resonance metalorganic molecular-beam epitaxy

Abstract

We have investigated the feasibility of depositing InN from nitrogen plasmas by electron cyclotron resonance metalorganic molecular‐beam epitaxy (ECR MOMBE) for use in ohmic contact formation. Resistivity, growth rate, and morphology were evaluated as a function of microwave power, growth temperature, and trimethylindium flux. Fine‐grained polycrystalline films with N/In ratios of 1.15 and resistivities as low as 190 μΩ cm were obtained under optimized growth conditions and represent the first demonstration of nitride growth by ECR MOMBE. Carbon and oxygen backgrounds were below the detection level of Auger electron spectroscopy. Ti/Pt/Au contacts deposited on InN yielded contact resistances of 5–6×10⁻⁷ Ω cm² and are thermally stable at normal alloying temperatures (∼380 °C).