Low-temperature direct growth of GaN epitaxial film on Cu substrate with sharp and abrupt hetero-interface

Abstract

GaN grown on high thermal conductivity substrate has attracted considerable attention for the preparation of high-power GaN-based devices. In this work, high-quality ∼300 nm-thick GaN epitaxial film with an in-plane epitaxial relationship of GaN[1 1−2 0]//Cu [1−1 0] has been directly grown on Cu substrate through controlling the interfacial reactions between GaN and Cu by low-temperature pulsed laser deposition growth of 450 °C. It reveals sharp and abrupt hetero-interface, small full-width at half-maximum for X-ray rocking curves of GaN(0 0 0 2) and GaN(1 0−1 2) of 0.5° and 0.8°, and very smooth surface, respectively. These high-quality GaN epitaxial films on Cu substrates shed light on the fabrication of high-power GaN-based optoelectronic and microelectronic devices.