PHOTO-MOCVD OF ZNO EPITAXIAL-FILMS

Photo-MOCVD of ZnO films on (0112) sapphire has been carried out over a growth temperature range of 350-500°C, using DEZ and NO2 as source materials and KrF excimer laser as a light source. When the laser light parallel to the substrate was passed above the substrate, the photochemical reactions occurred in the gas phase. In this case, the growth rate was affected but the crystallinity and electrical characteristics of films were not affected. When the laser light was directly incident on the substrate, surface reactions occurred, there was an increase in the growth rate, an improvement in crystallinity and a change in electrical characteristics. In addition, (1120) ZnO films were also grown epitaxially on (0112) sapphire substrates at 500°C. These results pro ve that surface reactions are very important factors in photo-MOCVD of ZnO epitaxial films. © 1990.