Patent ID: 11965797
Assignee: WUXI SENCOCH SEMICONDUCTOR CO., LTD.
Field: Measurement (Instruments)
Classification: CPC G  B | IPC B  G

Claim 4:
5. A preparation method of a bipolar transistor type MEMS pressure sensor, including:
providing a substrate, the substrate includes a first structural layer, a second structural layer disposed on the first structural layer, and a third structural layer disposed on the second structural layer along a thickness direction, and the substrate is provided with a first surface and a second surface, the first surface is provided with a compression area;
doping on the first surface to form a bipolar transistor, the bipolar transistor includes a base region, a collector region, and an emitter region, the base region is located within the pressure region and is respectively connected to the collector region and the emitter region; etching and forming a concave cavity at a corresponding position of the pressure area on the second surface to form a thin film on the substrate corresponding to the concave cavity; the cavity is formed in the first structural layer, and defines the first structural layer as a first thin film layer and a supporting structure supporting the first thin film layer;
etching the second structural layer to form a supporting layer, the supporting layer is overlapped with the first thin film layer, and defines the third structural layer as a second thin film layer overlapped with the supporting layer and a cantilever beam connected to the second thin film layer, and the collector region and the emitter region are located on the cantilever beam;
bonding the second surface with the substrate to form the bipolar transistor type MEMS pressure sensor.