Title :
A monolithic fully-integrated vacuum-sealed CMOS pressure sensor
Author :
Chavan, Abhijeet V. ; Wise, Kensall D.
Author_Institution :
Microelectron. Center, Delphi Delco Electron. Syst. Corp., Kokomo, IN, USA
fDate :
1/1/2002 12:00:00 AM
Abstract :
This paper presents an integrated multi-transducer capacitive barometric pressure sensor that is vacuum-sealed at wafer level. The interface circuitry is integrated directly within the sealed reference cavity, making the device immune to parasitic environmental effects. The overall device process merges CMOS circuitry with a dissolved-wafer transducer process and is compatible with bulk- and surface-micromachined transducers. The process employs chemical-mechanical polishing (CMP), anodic bonding, and hermetic lead transfers. The sensor achieves 25 mtorr resolution and is suitable for low-cost packaging. It is composed of a programmable switched-capacitor (SC) readout circuit, five segmented-range pressure transducers, and a reference capacitor, all integrated on a 6.5×7.5 mm2 die using 3 μm features
Keywords :
CMOS integrated circuits; capacitive sensors; chemical mechanical polishing; integrated circuit packaging; micromachining; microsensors; pressure sensors; programmable circuits; readout electronics; seals (stoppers); switched capacitor networks; 25 mtorr; 3 micron; 6.5 mm; 7.5 mm; CMP; MEMS; active pressure sensor; anodic bonding; bulk transducers; capacitive barometric pressure sensor; chemical-mechanical polishing; circuit design; dissolved-wafer transducer process; hermetic lead transfers; integrated multi-transducer pressure sensor; interface circuitry; low-cost packaging; monolithic CMOS micromachining process; monolithic CMOS pressure sensor; programmable SC readout circuit; reference capacitor; sealed reference cavity; segmented-range pressure transducers; structural design; surface-micromachined transducers; switched-capacitor readout circuit; transducer design; vacuum-sealed CMOS pressure sensor; Capacitive sensors; Chemical processes; Chemical sensors; Circuits; Costs; Micromechanical devices; Packaging; Silicon; Transducers; Wafer bonding;
Journal_Title :
Electron Devices, IEEE Transactions on
