THE ROLE OF DISLOCATION SCATTERING IN N-TYPE GAN FILMS

The lateral transport in GaN films produced by electron cyclotron reso nance plasma-assisted molecular beam epitaxy doped II type with Si to the levels of 10(15)-10(20) cm(-3) was investigated. The room temperat ure electron mobility versus carrier concentration was found to follow a family of bell-shaped corves consistent with a recently proposed mo del of scattering by charged dislocations. The mechanism of this scatt ering was investigated by studying the temperature dependence of the c arrier concentration and electron mobility. It was found that in the l ow carrier concentration region (< 10(17) cm(-3)), the electron mobili ty is thermally activated with an activation energy half of that of ca rrier concentration, This is in agreement with the prediction of the d islocation model. (C) 1998 American Institute of Physics. [S0003-6951( 98)02532-7].