Abstract
The metal oxide devices such as a thermistor and a varistor in the form of bulk or thick film which are applied for instruments, control and electronic circuits, have been developed. However, preparation of metal oxide thin film is difficult because of a high melting point of oxide material and irregular components including impurities. To solve this problem, the authors perceived that a low melting point metal becomes a metal oxide with a high melting point by oxidation, then devised the new method which after deposited according to order of Mn and Fe powder with high melting point from Zn with low melting point in vacuum, its multilayered metal can be converted into a metal oxide via profile of high temperature annealing in air. Through this process, the metal film with low melting point than annealing temperature does not disperse, so that a composite metal oxide semiconductor thin-film (COT) with thickness of 0.7-1.5μm is prepared. A markedly temperature dependent COT is suitable for a high sensitive microsensor responding to minute temperature change. The paper describes preparation of COT and construction of an enzyme sensor system based on chemical reaction heat for detecting nitrogen metabolite such as urea.
