| Summary: | 碩士 === 國立中興大學 === 機械工程學系所 === 97 === Wireless micro pressure sensors were manufactured using the standard 0.35 μm CMOS (complementary metal oxide semiconductor) process and a post-CMOS process. In this study, two different pressure sensors were designed, capacitive and FET (field effect transistor) type, and integration with different circuits. Wireless circuits included a ring oscillator and an antenna. The ring oscillator was used to generate RF (radio frequency) signal and the antenna was utilized to transmit the signal output. The capacitive pressure sensor changed in capacitance when applying a pressure to one, and the ring oscillator converted the capacitance variation of the sensor into the RF signal. The frequency of RF signal changed as the capacitance of the sensor varied. The EFT pressure sensor was combined with an amplifier that can amplify the output signal and increase the sensitivity of the sensor. The post-process employed the etchants to etch the sacrificial layers, and to release the suspended structures, and then used a PDS (parylene deposition system) to seal the etching holes in the pressure sensors.
The experimental results showed that the capacitive pressure sensor had a sensitivity of about 8 kHz/kPa and the FET pressure sensor had a sensitivity of about 0.08 mV/kPa. The sensitivity of output power in the FET pressure sensor was 0.0148
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