| 摘要 |
PURPOSE:To improve the strength and characteristics of a gas sensor by providing oxide film layers on both surfaces of an Si substrate, by providing elements of a temperature sensor and an electode of a Pt thin film on one oxide film, by forming passivation layers on the surfaces of the two elements, and by forming a catalyst layer on the other oxide film. CONSTITUTION:SiO2 films 11 and 16 are formed on the two surfaces of an Si substrate 10 respectively, and a Pt thin film 12 is formed on the film 11. Then, a temperature sensor element 13 of a Pt thin film 12a having a zigzag pattern, and an electrode element 14 serving as the electrode member of the element 13 and formed of a Pt thin film 12b, are formed by applying laser trimming or the like on the Pt thin film 12. Next, a passivation film layer 15 is formed for protecting the parts 13 and 14. Then, only the film 15 on the elecrode element 14 is removed to expose an electrode. On the other SiO2, a catalyst layer 17 formed of metal oxide is provided by evaporating Co, Cu, Fe, etc. in the ambience of O2. Next, the silicon substrate is divided along division lines 20 and 21 shown by alternate long and short dash lines and thereby chips are obtained. These chips are used as gas sensors. |
