CHARACTERIZATION OF n AND p TYPE ZNO THIN FILMS DEPOSITED BY CATHODIC PULSED FILTERED VACUUM ARC SYSTEM

Abstract

The transparent, conductive n and p-type semiconducting ZnO thin films were prepared by pulsed filtered cathodic vacuum arc deposition (PFCVAD) method. The structural, optical and electrical properties of n and p-type ZnO thin films are investigated after annealing at 450°C. 197 nm thick ntype ZnO thin film was deposited with oxygen pressure of 8.5x10 -4 Torr. XRD pattern of annealed ZnO thin film exhibits hexagonal structure with (100), (101) and (110) orientations. The crystallite size of semiconductor ZnO thin film is 18 nm, interplanar distance 0.16 nm and lattice constant c is 0.52 nm for (110) orientation. The optical transmittance spectra of n and p-type ZnO films are over 90% in the visible wavelength region with optical energy gap 3.3 eV. p-type ZnO thin films are produced by oxidation of PFCVAD deposited zinc nitride. Zinc nitride is deposited with nitrogen pressure of 8.6x10 -4 Torr and the thickness of this film is 179 nm. The oxidation of zinc nitride thin films at 450°C results in hexagonal structures p-type ZnO thin films. XRD pattern of this film has the same (100), (101) and (110) orientations with the same crystalline structures as the directly deposited ZnO thin film. Hall measurements indicated that ZnO films were p-type and the highest carrier concentration of 1.08x10 18 cm -3 and mobility of 93.53 cm 2 /Vs were obtained.