Title :
Three axis piezoresistive accelerometer using polysilicon layer
Author :
Kwon, Kijin ; Park, Sekwang
Author_Institution :
Dept. of Electr. Eng., Kyungpook Nat. Univ., Taegu, South Korea
Abstract :
A three axis piezoresistive accelerometer was fabricated from a polysilicon layer using SDB (silicon direct bonding) technology and LPCVD. The variations of stress according to each direction were utilized to detect the three dimensional acceleration and eliminate cross-axis sensitivities. TCO (temperature coefficient of offset) shifts for X, Y and Z-axis Wheatstone bridge outputs were only about 0~0.07[%F.S.], 0.028~-0.016[%F.S.] and 0.007~-0.004[%F.S.] in the 25°C~160°C range, respectively. The sensitivities of the fabricated sensor for X, Y and Z-axis acceleration were about 0.06[mV/V·g], 0.06[mV/V·g] and 0.13[mV/V·g] at room temperature. The cross-axis sensitivity for X, Y and Z-axis acceleration was about 0.0093[mV/V·g], which corresponds to the elimination of cross-axis sensitivities as designed
Keywords :
accelerometers; bridge instruments; chemical vapour deposition; elemental semiconductors; internal stresses; micromachining; microsensors; piezoresistive devices; silicon; 25 to 160 C; FEM simulation; LPCVD; Si; Wheatstone bridge outputs; X-axis acceleration; Y-axis acceleration; Z-axis acceleration; bulk micromachining technology; cross-axis sensitivity elimination; polysilicon layer; silicon direct bonding technology; stress variations; temperature coefficient of offset shifts; three axis piezoresistive accelerometer; three dimensional acceleration detection; Acceleration; Accelerometers; Bridge circuits; Compressive stress; Electrical equipment industry; Micromachining; Piezoresistance; Silicon; Temperature sensors; Tensile stress;
Conference_Titel :
Solid State Sensors and Actuators, 1997. TRANSDUCERS '97 Chicago., 1997 International Conference on
Conference_Location :
Chicago, IL
Print_ISBN :
0-7803-3829-4
DOI :
10.1109/SENSOR.1997.635428