Investigation of arsenic-doped ZnO thin films grown on Si substrate by atmospheric-pressure metal-organic chemical vapor deposition

Abstract

Zinc oxide (ZnO) thin film was grown on semi-insulating Si substrate using arsine (AsH3) as precursor by atmospheric-pressure metal-organic chemical vapor deposition (AP-MOCVD). In recently reported results, the physical mechanisms for As-doped ZnO thin films are explained as As substitution for oxygen (AsO) or As substitution for Zn and As combined with two Zn vacancies (AsZn2VZn). In this study, we control the in situ annealing ambient into two environments with various temperatures, which are Zn-rich, using diethylzinc (DEZn) as ambient gas, and O-rich, using water vapor as ambient gas, respectively. This should help to create AsO and AsZn2VZn. The ZnO thin film after in situ thermal annealing with H2O vapor ambient at 550 and 750 degrees C show p-type conductivity with hole concentration of 2.651 x 10(17) and 1.782 x 10(18)?cm-3, Hall mobilities of 10.08 and 5.402?cm2/V?s, and resistivities of 2.368 and 0.6485?O?cm, respectively.