Abstract: The monolithic integrated micro sensor is an important direction in the fields of integrated circuits and micro sensors.In this paper,a monolithic themral vacuum sensor based on a micro-hotplate (MHP) and operating under constant bias voltage conditions was designed.A new monolithic integrating mode was proposed,in which the dielectric and passivation layers in standard CMOS processes were used as sensor structure layers,gate polysilicon as the sacrificial layer,and the second polysilicon layer as the sensor heating resistor.Then, the fabricating processes were designed and the monolithic thermal vacuum sensor was fabricated with a 0.6μm mixed signal CMOS process followed by sacrificial layer etching technology.The measurement results show that the fabricated monolithic vacuum sensor can measure the pressure range of 2~1E5Pa and the output voltage is adjustable.

Key words: thermal vacuum sensor, monolithic integration, CMOS, micro hotplate