DocumentCode :
1852174
Title :
Polysilicon sensors for CMOS-MEMS electrothermal probes
Author :
Liu, J. ; Noman, M. ; Bain, J.A. ; Schlesinger, T.E. ; Fedder, G.K.
Author_Institution :
ECE Dept., Carnegie Mellon Univ., Pittsburgh, PA, USA
fYear :
2009
fDate :
21-25 June 2009
Firstpage :
2425
Lastpage :
2428
Abstract :
We describe multiple embedded polysilicon resistive sensors in CMOS-MEMS electrothermal probes as a step toward creating probe arrays for passing current on ICs to reconfigure resistance change (RC) vias. When not in contact, a low-resistivity unsilicided polysilicon (LP) resistor detects probe displacement indirectly through the temperature coefficient of resistance (TCR) effect. When in contact with a load force, the difference of two LP resistors, one under stress in the flexure and the other cantilevered, cancels the TCR and extracts the piezoresistive (PZR) change, thus working as a force sensor. With a 10 V, 37.15 mW drive, at loads less than 10 muN, the achieved force sensitivity is constant and matches within 3.1% to the sensitivity extracted by mechanically pushing on the tip. The sensitivity decreases at large loads due to the unequal thermal boundary conditions of the two LP resistors. A third silicided polysilicon (SP) resistor having near zero piezoresistance is added to detect the thermal boundary condition change thereby extending the maximum detectable load.
Keywords :
CMOS integrated circuits; electric sensing devices; elemental semiconductors; micromechanical devices; piezoresistive devices; probes; resistors; silicon; CMOS-MEMS electrothermal probes; IC; Si; flexure stress; force sensitivity; force sensor; low-resistivity unsilicided polysilicon resistor; multiple embedded polysilicon resistive sensors; piezoresistive change; polysilicon sensors; power 37.15 mW; probe displacement; reconfigure resistance change vias; temperature coefficient of resistance effect; thermal boundary conditions; voltage 10 V; Boundary conditions; Electrothermal effects; Force sensors; Log periodic antennas; Piezoresistance; Probes; Resistors; Sensor arrays; Thermal loading; Thermal resistance; CMOS MEMS; electrothermal; piezoresistive sensing; probes;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Solid-State Sensors, Actuators and Microsystems Conference, 2009. TRANSDUCERS 2009. International
Conference_Location :
Denver, CO
Print_ISBN :
978-1-4244-4190-7
Electronic_ISBN :
978-1-4244-4193-8
Type :
conf
DOI :
10.1109/SENSOR.2009.5285434
Filename :
5285434
Link To Document :
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