Al2O3-A1N ceramic micro hotplate gas sensor of annular heater

The invention discloses an Al2O3-A1N ceramic micro hotplate gas sensor of an annular heater. The Al2O3-A1N ceramic micro hotplate gas sensor comprises a substrate, a heat conduction medium layer, a heater electrode, a signal electrode, bonding pads, heat isolation through holes and a sensitive membrane, wherein a heating region in the center of the sensor adopts an annular heater design; the annular heat isolation through holes are designed around the annular heater, so that the heat conduction loss is reduced. The substrate of the sensor adopts an Al2O3 ceramic substrate; an A1N heat conduction medium membrane is formed on the surface of the Al2O3 ceramic substrate through magnetron sputtering; the Pt membrane heating electrode and the signal electrode are prepared on the A1N medium membrane through a flexible mechanical photoetching stripping process; the heat isolation through holes can be etched by a laser micro-processing technology. By the design of the annular heater and the semi-annular heat isolation