Electrical Trimming Characteristics of Polysilicon Nanofilms with Different Doping Concentrations and Deposition Temperatures

Abstract

Polysilicon nanofilm (PSNF) can provide a large gauge factor and good temperature stability, which promotes their application in piezoresistive sensing devices. Electrical trimming is necessary to further improve the stability and matching of piezoresistive resistors after sensor fabrication. The advantages of PSNF are realized by first preparing PSNF samples with different doping concentrations and deposition temperatures. By applying an incremental DC current that is higher than the threshold current of the PSNF resistors, the PSNF resistors are trimmed and the resistance changes are measured. The results of electrical trimming show that the threshold current, trimming rate, and trimming error are related to the doping concentration and deposition temperature. According to tunneling piezoresistive theory and the interstitial-vacancy pair model, the experimental results are expounded. These results are useful for the design and fabrication of PSNF piezoresistive sensors.