Growth and Characterisation of Al_1-xCr_xN Thin Films by RF Plasma Assisted Pulsed Laser Deposition

抄録

Thin films of AlN, CrN and Al_1-xCr_xN were grown epitaxially on c-cut sapphire by radio frequency (RF) plasma assisted pulsed laser deposition (PLD). The PLD growth mode employed for these Al_1-xCr_xN films was by delta doping layers of CrN 0.05-0.10 nm thick between layers of AlN of approximately 3.6 nm thick giving an estimated 1.3% and 2.5% Cr doping. The substrate temperature, nitrogen pressure and power parameters of the RF plasma were varied to optimize crystalline growth. X-ray diffraction (XRD) confirmed hexagonal wurtzite thin film growth of highly crystalline AlN and highly crystalline cubic CrN. The electronic structure of these thin films was examined by x-ray absorption (XAS) and soft x-ray emission spectroscopy (XES) at the N K edge. These measurements are compared with the results of density functional calculations for wurtzite-AlN, cubic-CrN and wurtzite-Al_1-xCr_xN. [DOI: 10.1380/ejssnt.2009.497]