Growth of p-type and n-type m-plane GaN by molecular beam epitaxy

Plasma-assisted molecular beam epitaxial growth of Mg-doped, p-type and Si-doped, n-type m-plane GaN on 6H m-plane SiC is demonstrated. Phase-pure, m-plane GaN films exhibiting a large anisotropy in film mosaic (similar to 0.2 degrees full width at half maximum, x-ray rocking curve scan taken parallel to [112 ($) over bar0] versus similar to 2 degrees parallel to [0001]) were grown on m-plane SiC substrates. Maximum hole concentrations of similar to 7x10(18) cm(-3) were achieved with p-type conductivities as high as similar to 5 Omega(-1) cm(-1) without the presence of Mg-rich inclusions or inversion domains as viewed by cross-section transmission electron microscopy. Temperature dependent Hall effect measurements indicate that the Mg-related acceptor state in m-plane GaN is the same as that exhibited in c-plane GaN. Free electron concentrations as high as similar to 4x10(18) cm(-3) were measured in the Si-doped m-plane GaN with corresponding mobilities of similar to 500 cm(2)/V s measured parallel to the [112 ($) over bar0] direction. (c) 2006 American Institute of Physics.