Title :
CMOS-Integrated Poly-SiGe Piezoresistive Pressure Sensor
Author :
Gonzalez, P. ; Rakowski, M. ; Segundo, D. San ; Severi, S. ; De Meyer, K. ; Witvrouw, A.
Author_Institution :
IMEC, Leuven, Belgium
Abstract :
An integrated poly-SiGe-based piezoresistive pressure sensor, which is directly fabricated above 0.13 m Cu-back-end CMOS technology, is presented. This represents not only the first integrated poly-SiGe pressure sensor directly fabricated above its readout circuit but also the first time that a poly-SiGe MEMS device is processed on top of Cu-back-end CMOS. Despite the low processing temperature (455°C) to allow for above-CMOS integration, the poly-SiGe piezoresistive sensor alone (250 250 m2 membrane) showed a sensitivity of around 2.5 mV/V/bar. The same sensor exhibited a sensitivity of 159.5 mV/V/bar after on-chip amplification. The CMOS circuit showed no significant deterioration after the MEMS processing, although a resistance increase for the Cu-filled metal-to-metal and the tungsten-filled CMOS-MEMS vias was observed.
Keywords :
CMOS integrated circuits; Ge-Si alloys; copper; microfabrication; microsensors; piezoresistive devices; pressure sensors; readout electronics; CMOS integrated circuit; Cu-SiGe; Cu-backend CMOS technology; Cu-filled metal-to-metal CMOS; MEMS device; on-chip amplification; poly-SiGe piezoresistive pressure sensor; readout circuit; size 0.13 mum; tungsten filled CMOS; Annealing; CMOS integrated circuits; Metals; Micromechanical devices; Piezoresistance; Sensitivity; Silicon germanium; CMOS-integrated circuits; microelectromechanical systems (MEMS); piezoresistive devices; silicon germanium (SiGE);
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2012.2201689
