Growth and electrical properties of nonpolar and polar Ga-doped ZnO thin films on LaAlO3 and SrTiO3 substrates

Abstract Ga-doped ZnO (GZO) thin films were grown on LaAlO 3 (LAO) and SrTiO 3 (STO) substrates by using a pulsed laser deposition (PLD) technique at various substrate temperatures. It was found that the nonpolar a -plane GZO thin films were grown on LAO (1 0 0) substrates. However, the polar c -plane or the c -plane coexistent with the a -plane GZO films were obtained on STO (1 0 0) substrates. The in-plane orientational relationship between the GZO films and substrates was also investigated. The electrical properties of the films were deeply affected by the growth orientation. The GZO films with a -axis oriented phase showed higher resistivity than with c -oriented phase, which can be ascribed to the lower mobility due to the increase in grain boundary scattering.