掺杂浓度对多晶硅纳米薄膜应变系数的影响  

Influence of Doping Level on the Gauge Factor of Polysilicon Nano-Film

作　　者：揣荣岩[1] 刘晓为[1] 霍明学[1] 宋明浩[1] 王喜莲[1] 潘慧艳[1] 

机构地区：[1]哈尔滨工业大学MEMS中心

出　　处：《Journal of Semiconductors》2006年第7期1230-1235,共6页半导体学报（英文版）

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.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 ×10^20cm^-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.

关 键 词：多晶硅 纳米薄膜 压阻特性 隧道效应 应变系数 

分 类 号：O484.2[理学—固体物理]