High In content InxGa1−xN grown by energetic neutral atom beam lithography and epitaxy under slightly N-rich conditions

Abstract

Two series of In-rich InGaN films with compositions of ∼25% and ∼35% In, grown over a substrate temperature range from 490 to 620 °C, show how the film properties improve as the growth temperature is lowered below the InN decomposition temperature of ∼550 °C in vacuum. These InGaN films have been grown using a novel growth technique utilizing energetic N atoms as the active growth species. Under N-rich growth conditions, these InGaN films show how compositional uniformity, crystallinity, band edge photoluminescence, and surface morphology are improved as growth temperatures are reduced. The results emphasize the importance of energetic N atoms and lower substrate temperatures for overcoming difficulties associated with growing high-quality In-rich InxGa1−xN thin film materials. Utilizing energetic N atoms allows for the growth of high-quality, thick (>500 nm) InxGa1−xN films at temperatures below 500 °C.