title: Monolithic composite “pressure + acceleration + temperature + infrared” sensor using a versatile single-sided “SiN/Poly-Si/Al” process-module.
abstract: We report a newly developed design/fabrication module with low-cost  single-sided "low-stress-silicon-nitride (LS-SiN)/polysilicon (poly-Si)/Al" process for monolithic integration of composite sensors for sensing-network-node applications.  A front-side surface-/bulk-micromachining process on a conventional Si-substrate is developed, featuring a multifunctional SiN/poly-Si/Al layer design for diverse sensing functions. The first "pressure + acceleration + temperature + infrared" (PATIR) composite sensor with the chip size of 2.5 mm × 2.5 mm is demonstrated. Systematic theoretical design and analysis methods are developed. The diverse sensing components include a piezoresistive absolute-pressure sensor (up to 700 kPa, with a sensitivity of 49 mV/MPa under 3.3 V supplied voltage), a piezoresistive accelerometer (±10 g, with a sensitivity of 66 μV/g under 3.3 V and a -3 dB bandwidth of 780 Hz), a thermoelectric infrared  detector (with a responsivity of 45 V/W and detectivity of 3.6 × 107 cm·Hz1/2/W) and a  thermistor (-25-120 °C). This design/fabrication module concept enables a low-cost monolithically-integrated "multifunctional-library" technique. It can be utilized as a customizable tool for versatile application-specific requirements, which is very useful for small-size, low-cost, large-scale sensing-network node developments.
authors: State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China. nizao@mail.sim.ac.cn
authors: Zao
authors: Z
authors: Ni
authors: Chen
authors: C
authors: Yang
authors: Dehui
authors: D
authors: Xu
authors: Hong
authors: H
authors: Zhou
authors: Wei
authors: W
authors: Zhou
authors: Tie
authors: T
authors: Li
authors: Bin
authors: B
authors: Xiong
authors: Xinxin
authors: X
authors: Li