Modeling and Manufacturing of a Micromachined Magnetic Sensor Using the CMOS Process without Any Post-Process

Abstract

The modeling and fabrication of a magnetic microsensor based on a magneto-transistor were presented. The magnetic sensor is fabricated by the commercial 0.18 μm complementary metal oxide semiconductor (CMOS) process without any post-process. The finite element method (FEM) software Sentaurus TCAD is utilized to analyze the electrical properties and carriers motion path of the magneto-transistor. A readout circuit is used to amplify the voltage difference of the bases into the output voltage. Experiments show that the sensitivity of the magnetic sensor is 354 mV/T at the supply current of 4 mA.

A Three-Axis Magnetic Field Microsensor Fabricated Utilizing a CMOS Process

“…Leepattarapongpan et al [30] developed an MF microsensor with a 110 mV/T sensitivity. Tseng et al [10] made an MF microsensor whose sensitivity was 354 mV/T. The sensitivity of the MF microsensor in this work was higher than those of all three of these studies.…”

“…A standard 0.18 μm CMOS process of Taiwan Semiconductor Manufacturing Company (TSMC) was utilized to make the MF microsensor [10]. According to the MF microsensor model in Figure 1, we designed the layout of the MF microsensor.…”

“…A magnetotransistor mechanism [10] was used to design this 3-axis MF microsensor. Figure 1a demonstrates the three-axis MF microsensor structure.…”

“…Several transducers have been constructed on a smaller scale by a microelectromechanical system (MEMS) process [5][6][7][8]. Compared with traditional sensors, microsensors are easy to mass produce, are of high quality, are small, and have a low cost [9][10][11][12]. Recently, many MF microsensors have been developed utilizing the MEMS method.…”

Fluxgate Magnetometer with an Orthogonal Flux Guide

“…Fluxgate magnetometers are typically applied in craft navigation, military detection and medical recognition [3]. So far prospective applications of micro-fluxgates have been considerably developed for modern digital navigation , thoracoscopic surgery , and nondestructive inspection [4]. On device characterization of fluxgate magnetometers, several earlier works concluded that the sensing methodology and sensitivity enhancement by adopting the multiple harmonic frequency analysis techniques are practicable [5].…”