DocumentCode :
2473579
Title :
Fabrication and characterization of piezoresistive strain sensors for high temperature applications
Author :
Fraga, M.A. ; Furlan, H. ; Wakavaiachi, S.M. ; Massi, M.
Author_Institution :
Lab. de Plasmas e Processos, Inst. Tecnol. de Aeronaut., São Paulo, Brazil
fYear :
2010
fDate :
14-17 March 2010
Firstpage :
513
Lastpage :
516
Abstract :
In this work, we studied the fabrication and characterization of strain sensors based on semiconductor materials for high temperature applications: non-stoichometric amorphous silicon carbide (a-SixCy) thin film and SOI (Silicon-On-Insulator) substrates. a-SixCy were deposited onto thermally oxidized (100) Si wafers by plasma enhanced chemical vapor deposition (PECVD) technique using silane (SiH4) and methane (CH4) as precursor gases. The SOI wafer used had a sandwich structure of a 0.2 μm thick top p-type Si layer, 0.5 μm thick buried oxide (BOX) layer and 250 μm Si substrate. The piezoresistive strain sensitivity element in the sensors is a a-SixCy thin-film resistor or a Si p-type resistor formed on SOI substrate. Gauge factor (GF) measurements were done using the beam-bending method. One resistor of each type was bonded near the clamped edge of a stainless steel cantilever beam and on the free edge were applied different forces. The electrical resistance of each resistor was measured without applied load on the beam and during subsequent tensile load. The temperature coefficient of resistance (TCR) also was investigated from room temperature up to 250°C. The results indicate that the a-SixCy thin-film resistor has a GF of 48 and a TCR of 35 ppm/°C whereas p-type Si on SOI substrate has gauge factor of 22 and TCR of 140 ppm/°C.
Keywords :
CVD coatings; amorphous semiconductors; cantilevers; high-temperature techniques; piezoresistive devices; semiconductor thin films; silicon compounds; silicon-on-insulator; strain sensors; substrates; thin film resistors; GF measurement; PECVD technique; SOI substrates; SOI wafer; SiC; TCR; beam-bending method; buried oxide layer; electrical resistance; gauge factor measurement; high temperature applications; methane; nonstoichometric amorphous silicon carbide thin film; piezoresistive strain sensors fabrication; plasma enhanced chemical vapor deposition; precursor gases; semiconductor materials; silane; silicon-on-insulator substrates; size 0.2 mum; size 0.5 mum; size 250 mum; stainless steel cantilever beam; temperature 293 K to 548 K; temperature coefficient of resistance; thin film resistor; Capacitive sensors; Fabrication; Piezoresistance; Plasma temperature; Resistors; Semiconductor thin films; Sensor phenomena and characterization; Substrates; Temperature sensors; Thin film sensors;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Industrial Technology (ICIT), 2010 IEEE International Conference on
Conference_Location :
Vi a del Mar
Print_ISBN :
978-1-4244-5695-6
Electronic_ISBN :
978-1-4244-5696-3
Type :
conf
DOI :
10.1109/ICIT.2010.5472747
Filename :
5472747
Link To Document :
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