TCAD-BASED MAGNETIC ANALYSIS OF 2D-MagFinFET IN ORTHOGONAL DIRECTIONS FOR MEDICAL MICR0-ROBOTS APPLICATION

Abstract

The need for magnetic sensor is aggressively increasing in medical area to navigate the medical micro-robots through the blood vessels to target. This dissertation presents a detailed TCAD based investigation of novel Two Directional Magnetic Fin Field Effect Transistor (2D-MagFinFET) magnetic sensor based on the advanced 3D architecture of Field Effect Transistor. The proposed device is designed to overcome the limitation of traditional magnetic sensor to only sense the single direction magnetic field. The proposed device is designed to sense orthogonal magnetic field in Y and Z direction. It is operated on concept of Lorentz force act on charge carrier in channel when external magnetic field applied which deflect the carrier from their path which governs differential current (∆ID). Device uses two parallel fins to sense the magnetic field. One fin will detect the magnetic field of Y-direction and other one of Z-direction without any coupling of relative sensitivity. Two layers of SiO2/HfO2 as gate dielectric is used to enhance the overall performance of the proposed device. The performance of the proposed device is analyzed in terms of SS, VTH, ION, IOFF, DIBL, SR, magnetic sensitivity (SA) and Relative magnetic sensitivity (SR). The proposed device demonstrates a SS of 59.96 mV/dec which is improved by 4.83% in contrast to existing devices. The VTH of device is increased from 0.21 V to 0.48 V by 128.57% which help to protect the sensor to turn on accidently. IOFF and ION currents of the proposed device is 5.24 fA and 12.9 µA having SR of 2.39 × 109. The proposed device has a DIBL of 8.24 mV/V at gate length of 50 nm show how efficiently device overcome the problem of short channel effect. These results demonstrate the better switching and performance of proposed device than the existing device. The magnetic response shows the linear dependency of differential current (∆IY and ∆IZ) with Magnetic field having a sensitivity of 159.27 nA/T in Y-direction and 147.13 nA/T in Z-direction at 100 µA biased current. The relative sensitivity is 0.00159 T-1 and 0.00147 T-1 in Y and Z direction respectively, improved from recently reported device. Owing the magnetic sensitivity in orthogonal direction the proposed device is suitable for the spatial tracking and navigation of medical micro-robots.