TiO2 sensitive layer structure used for oxygen sensor and preparation method thereof
The invention relates to a TiO2 sensitive layer structure used for an oxygen sensor and a preparation method of the TiO2 sensitive layer. By subjecting the TiO2 sensitive layer structure to reticulate processing, crack formation and spread can be inhibited, so that thermal stress caused cracks can be effectively reduced. And the increase of a surface-volume ratio facilitates oxygen adsorption, thus enhancing the TiO2 sensitive layer sensitivity and reducing the response time. The preparation method of the TiO2 sensitive layer provided in the invention is carried out on a silicon substrate equipped with heating wires, and consists of: first preparing an insulating layer on the heating wires, preparing interdigital electrodes on the insulating layer, then preparing a TiO2 film on the interdigital electrodes, and performing reactive ion etching to make the TiO2 film into a reticulate structure. 1. One kind is used for oxygen sensor TiO2 sensitive layer structure, including the upper surface of the insulating layer and the interdigitated electrode Pt the TiO2-sensitive layer, the electrode layer is arranged below the removed Pt Ti bonding layer, the shape and is matched with Pt interdigitated electrode, wherein the insulating layer, the lower layer, the upper, heating is arranged between the lower insulating layer, characterized in that the stated TiO2-sensitive layer is doped with the Pt TiO2 layer, the geometrical characteristics of the plane thereof for the porous mesh structure. 2. For oxygen sensor TiO2 sensitive layer structure according to Claim 1, characterized in that the said porous mesh structure TiO2-sensitive layer, its mesh-wire wide for the 2-4 m; and the side length of the mesh of the net the 4-8 m square. 3. For oxygen sensor TiO2 sensitive layer structure according to Claim 1, characterized in that the outermost layer which is the side length of the mesh line 74-148 the large m square. 4. For oxygen sensor TiO2 sensitive layer structure according to Claim 2, characterized in that the stated Pt interdigitated electrode, the width of the interdigital width is just network; is the same as distance between the fingers of the side length of the mesh. 5. One kind is used for oxygen sensor TiO2 method for the preparation of the sensitive layer, the oxygen sensor on the basis of use for TiO2 structure of the sensitive layer according to Claim 1, characterized in that comprises the following steps: The insulating layer for a. definition of the tray photolithography Pt removed from the surface of the shape and position of the electrode; B. Using sputtering method sputtering 50 nm thick Ti as the Ti bonding layer, then sputtering 150 nm thick Pt, using the ultrasonic stripping technique is used for removing the adhesive film forming interdigitated electrode; C. by sol-gel method of preparing titanium-containing ionic latex, uniform bonded joint applied to the interdigitated electrode for the position on the upper insulating layer, and covering the interdigitated electrode, the 500 the drying [...] , forming TiO2 film layer; D. with the photoresist as a masking layer, the reactive ion etching method utilizing TiO2 film layer is etched to be square-reticular structure, and at the same time etching leaves the fork finger electrode lead wire coil. 6. For oxygen sensor TiO2 method for the preparation of the sensitive layer according to Claim 5, characterized in that the porous net structure TiO2-sensitive layer, its mesh-wire wide for the 2-4 m; and enclosed by the mesh of the net is square, the side length the 4-8 m. 7. For oxygen sensor TiO2 method for the preparation of the sensitive layer according to Claim 5, characterized in that the most outer mesh-wire form a large square, the side length the 74-148 m. 8. For oxygen sensor TiO2 method for the preparation of the sensitive layer according to Claim 6, characterized in that the stated Pt interdigitated electrode is the same as the width of the interdigitated part of the width of the mesh lines; is the same as distance between the fingers of the side length of the mesh. 9. For oxygen sensor TiO2 method for the preparation of the sensitive layer according to Claim 5, characterized in that the titanium-containing emulsion, added with acetyl acetone platinum , the Pt:of Ti atom number ratio is 0.05.