TIN OXIDE THIN FILM SENSOR FOR DETECTING HYDROGEN GAS AND ITS METHOD

PROBLEM TO BE SOLVED: To improve the sensitivity to hydrogen by providing an insulating film existing on a semi-conductor substrate, a lower electrode existing on the insulating film, and a tin oxide thin film formed by an ion beam vapor deposition method. SOLUTION: An insulating film 102 preferably a silicon dioxide film is provided on a semi-conductor substrate 100. A lower electrode 104 preferably composed of platinum or palladium is provided on the insulating film 102. A tin oxide thin film 106 to perform a function as a sensor is spread on the electrode 104 and a portion of the insulating film 102 having no electrode 104 with thickness kept to 100-1000 , representatively 400 , to compose the hydrogen sensing tin oxide thin film sensor. The manufacturing method is desirably to form the insulating film 102 and the lower electrode 104 by an ion beam sputtering and the tin oxide thin film 106 by an ion beam vapor deposition method. Sputtering and vapor deposition made through ion beam are carried out under high vacuum.