【摘要】 为有效利用多晶硅纳米薄膜研制MEMS压阻器件,本文对LPCVD多晶硅纳米薄膜应变系数与掺硼浓度的关系进行了研究,并利用扫描电镜和X射线衍射实验分析了薄膜的结构特点.结果表明:在重掺杂情况下,纳米薄膜的应变系数明显大于相同掺杂浓度下单晶硅的应变系数,而且掺杂浓度在2.5×1020cm-3左右时,应变系数具有随掺杂浓度升高而增大的趋势.对这种实验结果依据隧道效应原理进行了理论解释,提出了多晶硅压阻特性的修正模型.更多还原

【Abstract】 For the purpose of aiding the development of effective MEMS strain sensors using polysilicon nano-film,we investigate the relationship between the B-doped concentration and the gauge factor of LPCVD-grown polysilicon nano-film and analyze the structure of the film via scanning electron photomicrographs and X-ray diffraction-spectra.Experiments show that under a heavy doping condition,the gauge factor of the nano-film is significantly larger than that of monocrystalline silicon with the same doping level,and when the doping concentration is around 2.5×10²⁰cm^-3,the gauge factor of the film increases with the increase of the doping concentration.These results are explained by the tunneling effect.A modified model of piezoresistive properties for polysilicon is then presented constructively.更多还原