压阻掺杂浓度对高g_n加速度计动态性能影响

Effect of impurity concentration of piezoresistor on dynamic shock response performance of high g_n accelerometer

采用有限元方法研究在不同压阻工作温度下压阻掺杂浓度对高gn加速度计动态冲击性能的影响。结果表明：器件动态冲击响应是受迫振动与悬臂梁固有振动叠加的结果，且压阻灵敏度系数与工作温度成正比。当T〈20℃时，悬臂梁固有振动明显，并且，器件动态冲击响应峰值电压随着压阻掺杂浓度升高而降低；当r在20℃附近，峰值电压随掺杂浓度变化不明显；当T〉20℃时，随着温度升高，悬臂梁固有振动频率渐受压制，传感器动态冲击响应渐表现为受加速度冲击受迫振动，且峰值电压随掺杂浓度提高而增大。在1×10”～1×10^21cm^-3。范围内，在0，20，100℃时，峰值电压差值分别为2，0，9mV。

The effect of impurity concentration of piezoresistor on the dynamic shock response of a high g, MEMS aceelerometers at various piezoresistor temperatures is investigated by using finite element method（FEM）. Results show that the dynamic responses of component are the superposition of the forced vibration with dynamic shock and vibration of cantilever in its inherent frequency. When the working temperature of the piezoresistor is below 20℃, the inherent vibration of cantilever became outstanding, and with the increase of impurity concentration of piezoresistor,the peak output voltage decreased. When it is equal to 20 ℃, the peak output voltage is nearly invariable with the impurity concentration of piezoresistor. While it goes beyond 20 ℃, with the increase of working temperature of piezoresistor, the inherent vibration of cantilever becomes weaker and weaker, the output result gradually behaved as the forced vibration under dynamic shock and the peak output voltage increased with the increase of impurity concentration of piezoresistors. Under 0,20,100 ℃ condition, the difference between the peak output voltage at 1 ×10^18 cm^-3 impurity concentration of piezoresistor, and that at 1 × 10^21 cm^-3 is about 2,0,9 mV respectively.