METAL OXIDE THIN FILM GAS SENSOR ELEMENT

摘要

PURPOSE:To obtain a uniform performance sensor with a high sensitivity dispensing with any doping process, by using an evaporation material source of metal or metal oxide to form an evaporation layer having a specified crystal orientation property with respect to the interface to contact a vapor phase. CONSTITUTION:After an oxide insulation layer 3 such as SiO2 is formed on the surface of Si or the like as substrate 1, a metal oxide thin film semiconductor layer 5 is to be formed by physical evaporation method or chemical evaporation method. The evaporation material source herein use shall be metal such as Sn, Zn and the like or the oxide thereof. Then, when the semiconductor layer 5 is formed under a specified condition depending on the material of the substrate 1, type of the evaporation material source, evaporation method and the like, the layer 5 is formed having a specified crystal orientation property with respect to the interface to contact a gaseous phase. For example, when the intensity of diffracted X rays as obtained when CuK as ray source is subjected to an X rays diffraction is I1-I4 sequentially, the ray intensity on (211) face and (110) face will be the highest. This enables the formation of the semiconductor layer 5 to meet a specified requirement of I2/I1=0.6 as well as half power width of I1 exceeding 0.58 and the like.