Characterization of Zinc Oxide Films Grown by a Newly Developed Plasma Enhanced Metal Organic Chemical Vapor Deposition Employing Microwave Excited High Density Plasma

The radical reaction based semiconductor manufacturing has been applied to silicon device process. Such as SiO2 and Si3N4 can be formed at low temperatures of under 500–600 °C. In this study, we applied radical reaction based semiconductor manufacturing to compound semiconductor of ZnO. The characteristics of ZnO films grown by a newly developed plasma enhanced metal organic chemical vapor deposition (MOCVD) employing microwave excited high-density plasma are good. The film formed on a-plane sapphire is epitaxially oriented in c-axis direction, and the composition is similar to ZnO substrate grown by hydrothermal method. The mobility of grown film at around 400 °C is 23 cm2/(Vs), and it is increased to 46 cm2/(Vs) by 700 °C annealing. The carbon concentration in the films can be reduced by the selection of a zinc precursor and the optimization of process conditions. The active species of plasma are effective for the crystallization of films.