Analysis of Tunneling Piezoresistive Effect of P-Type Polysilicon Nanofilms

Abstract

The polysilicon nanofilms have significant piezoresistive characteristics. In this paper, an analysis of tunneling piezoresistive effect of p-type polysilicon nanofilms is presented based on the experimental data. The analysis results show that the tunneling piezoresistive effect is much remarkable than piezoresistive effect of neutral region, and the former is about 1.3 to 1.5 times of the latter. The higher is doping concentration, the more remarkable tunneling piezoresistive effect is. This advantage can be utilized to improve the temperature characteristics of polysilicon piezoresistive sensor.

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

“…When the deposition temperature is lower than 620°C, the degree of crystallization of polysilicon is weak because of the low temperature. According to our tunneling piezoresistive theory [5], the grain boundary plays a dominant role in polysilicon, so the gauge factor is higher; when the 3 Journal of Nanomaterials deposition temperature is higher than 620°C, the degree of crystallization of polysilicon becomes stronger because of the high temperature. The impact of the grain boundary decreases, so that the gauge factor is lower.…”

“…The grain boundary is a complex structure, usually consisting of a few atomic layers of disordered atoms. According to tunneling piezoresistive theory [4,5], the resistance of PSNF (R p ) consists of the grain resistance (R g ) and the grain boundary resistance (R b ), as shown in Figure 6.…”

“…In recent years, polysilicon nanofilm (PSNF, thickness of less than 100 nm) has received increasing attention. According to our previous research, PSNF has favorable performance because it has a remarkable tunneling piezoresistive effect [4,5]. PSNF can play an important role as a pressuresensitive material in MEMS sensors, especially in hightemperature piezoresistive sensors.…”

Optimized Technical Characteristics of Polysilicon Nanofilm

“…The gauge factor of 89nm PSNF is highest, 33.39; and the gauge factor of 60nm PSNF is 32.32. Because of remarkable tunneling piezoresistive effect, the piezoresistive characteristics of PSNF exceed that of CPSF [4].…”

“…PSF plays an important role as a pressure-sensing material in Micro-electromechanical Systems (MEMS), and especially represents preferable properties used in high temperature piezoresistive devices. According to our previous research, the piezoresistive characteristics of PSNF exceed that of CPSF because of remarkable tunneling piezoresistive effect [4]. In order to apply of PSNF to piezoresistive sensor effectively, it is very necessary to investigate the technical parameters of preparation of PSNF.…”