Question

5. Answer following questions (10 pts) Find the longitudinal gauge factor of piezoresistor when a longitudinal piezoresistor is embedded on the top surface of a silicon cantilever and the cantilever points in the <1 1 1> direction. (Young Modulus of silicon is 168MPa and the piezoresistor is n-type doped with resistivity of 11.7 2 cm. TABLE 6.1 Table of Piezoresistivity Components TABLE 6.2 ua for Transverse con under Certain Doping Values. Various Commonly Encountered Resistor Configurations. Piezoresistance coefficient (10"Pa 1) Direction Direction of strain Piezoresistive of current Configuration coefficient n-type (resistivity 11.7 Ωcm) 100 100 110 110 <100 010 110 Longitudinal Transverse π12 ( 1 + π12 + π44y2 -102.2 Longitudinal Transverse П12 Π44 -13.6 Longitudinal 22T)2

Answer 1