A pathway to strain-free AlGaN grown on native GaN substrates
Abstract
We demonstrate that facet-controlled epitaxial lateral overgrowth enables the formation of regular, strain-relieving misfit dislocation (MD) arrays at {11−22} interfaces and results in relaxed growth of AlGaN on native GaN substrates (threading dislocation density <104 cm−2). Complementary plan-view and cross-sectional transmission electron microscopy studies confirmed the presence of uniform MD arrays with spacing matching the value predicted for an ideal, strain-relieving array. The MDs exhibited a pure edge-type Burgers vector (b = 1/3 ⟨11−20⟩) and were aligned parallel to [1−100]. Based on these results, we outline a pathway to achieve low threading dislocation densities in thick, relaxed, crack-free AlGaN epilayers grown on native GaN.
Article Details
Journal Info
Journal of Applied Physics
American Institute of Physics
Authors (7)
Michael Carter
Department of Materials Science and Engineering, North Carolina State University 1 , Raleigh, North Carolina 27695,
Jack Almeter
Department of Materials Science and Engineering, North Carolina State University 1 , Raleigh, North Carolina 27695-7919,
Shashwat Rathkanthiwar
Department of Materials Science and Engineering, North Carolina State University 1 , Raleigh, North Carolina 27695,
Ronny Kirste
Department of Materials Science and Engineering, North Carolina State University 3 , Raleigh, North Carolina 27695,
Seiji Mita
Adroit Materials 2 , 2054 Kildaire Farm Rd., Cary, North Carolina 27518,
Ramón Collazo
Department of Materials Science and Engineering, North Carolina State University 3 , Raleigh, North Carolina 27695,
Zlatko Sitar
Department of Materials Science and Engineering, North Carolina State University 3 , Raleigh, North Carolina 27695,