Coupling effect in field Hall elements based on thin-film SOI MOS transistors

V.D Kirilov,Aleksey V Leonov,Dmitry N Ivanov,Victor N Murashev

doi:10.3897/j.moem.6.4.65567

Abstract

The influence of the coupling effect on the parameters of field Hall elements based on thin-film MOS transistors has been studied. Analysis of the development of today’s microelectronics shows the necessity of developing the element base for high performance sensors based on silicon technologies. One way to significantly improve the performance of sensing elements including magnetic field sensors is the use of thin-film transistors on the basis of silicon on insulator (SOI) structures. It has been shown that field Hall sensors (FHS) may become the basis of high-performance magnetic field sensors employing the coupling effect occurring in the double gate vertical topology of these sensing elements. Electrophysical studies of FHS have been conducted for different gate bias and power supply modes. The results show that the coupling effect between the gates occurs in FHS if the thickness of the working layer between the gates is 200 nm. This effect leads to an increase in the effective carrier mobility and hence an increase in the magnetic sensitivity of the material. Thus field Hall elements based on thin-film transistors fabricated using silicon technologies provide for a substantial increase in the magnetic sensitivity of the elements and allow their application in highly reliable magnetic field sensors.

Highlights

Over the last decades microelectronics industry has been developing at a fast pace since it is directly related to the development of information technologies, industrial automation and Internet of things which provide for effective control of human life space
The aim of this work is to study the effect of gate voltage on the Hall voltage in field Hall sensors (FHS) in the form of magnetically sensitive thin-film double gate silicon on insulator (SOI) MOS transistor with probes at two opposite sides of the n-Si channel
In this work we studied the current and Hall characteristics of the FHS for different gate bias modes: 1) variable bias is applied to each of the gates separately while the other gate has a zero bias and 2) equal bias is applied to both the gates simultaneously

Summary

Introduction

Over the last decades microelectronics industry has been developing at a fast pace since it is directly related to the development of information technologies, industrial automation and Internet of things which provide for effective control of human life space. A distinctive feature of fully depleted SOI MOS transistors is the coupling effect, i.e., a correlation between the interface potentials of the Si thin film in which the device is fabricated and the surrounding dielectric [11–14]. This coupling effect may lead to a dependence of the SOI layer conductivity on the transistor control gate bias and the substrate metallization voltage. The aim of this work is to study the effect of gate voltage on the Hall voltage in field Hall sensors (FHS) in the form of magnetically sensitive thin-film double gate SOI MOS transistor with probes at two opposite sides of the n-Si channel. The SOI FHS operation principle is electron accumulation at the Si–SiO2 interface boundaries separated by the partial depletion zone

Experimental

Results and discussion

Conclusion