摘要
利用低压化学气相沉积（LPCVD）技术制备了不同掺杂浓度的多晶硅纳米薄膜，并对样品的压阻特性进行了测试．采用最小二乘法对实验数据进行拟合，得到了应变系数及其线性度与掺杂浓度的关系．实验结果表明：掺杂浓度从8．1×10^18cm^-3变化至7．1×10^20cm^-3，多晶硅纳米薄膜的纵向和横向应变系数先增加再减小，最后基本不再随掺杂浓度而变化，且纵向应变系数大于横向应变系数：掺杂浓度低于4.1×10^19cm^-3时，应变系数的非线性较大，且随掺杂浓度的升高而迅速减小；掺杂浓度高于4．1×10^19cm^-3时，应变系数的非线性较小并出现波动现象，同时纵向应变系数的非线性小于横向应变系数的非线性．利用隧道压阻理论对实验结果进行了分析．结合以前的研究结果可知，适合传感器制作的多晶硅纳米薄膜的优化掺杂浓度应为（2．0～4．1）×10^20cm^-3，为进一步利用多晶硅纳米薄膜制作传感器提供了非常有价值的参考信息．
The polysilicon nanofilms with different doping concentrations were prepared by low pressure chemical vapor deposition （ LPCVD ） ; the piezoresistive properties of samples were tested. The relations between doping concentration and gauge factor, linearity were obtained by the method of least squares. The experimental results show that, when the doping concentration increases from 8.1×10^18 cm^-3 to 7.1×10^20 cm^-3, the longitudinal and transverse gauge factors first increase, then decrease, and basically keep constant at last, and the longitudinal gauge factor is bigger than the transverse one. When doping concentration is lower than 4.1×10^19 cm^-3, the nonlinearity of gauge factors is high, and decreases rapidly with the increase of doping concentration. When doping concentration is higher than 4.1×10^19 cm^-3, the nonlinearity of gauge factors is low and fluctuates. The nonlinearity of longitudinal gauge factor is lower than that of transverse gauge factor. The experimental results are explained with tunneling piezoresistive theory. Combined with the previous research, it proves that the optimized doping concentration of polysilieon nanofilms for sensor design is （2.0-4.1）×10^20 cm^-3. The conclusions are very useful for fabrication of sensors utilizing the polysilicon nanofilms.
出处
《纳米技术与精密工程》
EI
CAS
CSCD
2009年第1期5-9,共5页
Nanotechnology and Precision Engineering
基金
国家自然科学基金资助项目(60776049)
关键词
多晶硅纳米薄膜
应变系数
线性度
掺杂浓度
隧道压阻理论
polysilicon nanofilms
gauge factor
linearity
doping concentration
tunneling piezoresistive theory
