Ga O thin films for high-temperature gas sensors

Gallium oxide thin films have promising properties for high-temperature-stable and n-type semiconducting properties at high temperatures above 6008C. The film function of gallium oxide is considered to detect oxygen as bulk-control-type sensors over 9008C, and also to detect reducing gases as surface-control-type sensors in the temperature range of 5008–8508C. Gallium oxide thin films were deposited by rf magnetron sputtering. Annealing process was performed to improve the film crystallinity. Crystallization and composition analysis were confirmed with XRD and AES measurements. It was found that oxygen content in gallium oxide is deficient in the sputtered film. Moreover, crystallization and electrical conductivity are controllable by sputtering conditions such as substrate temperature, gas pressure and others. q1999 Elsevier Science B.V. All rights reserved.