4.1 The Structure

A two-drain MAGFET is a magnetic sensor based on a MOSFET. Its structure is identical to a MOSFET but the drain is split in two or more parts [25,33,42]. In this chapter, a two-drain MAGFET built with a 10 $ \mu $m standard CMOS process will be analyzed. The substrate doping is of $ 1\times 10^{15}\; \mathrm{cm}^{-3}$ and the oxide thickness is of 60 nm. The metallurgical junction is of 1 $ \mu $m and the source/drain doping is of $ 5\times 10^{18}\; \mathrm{cm}^{-3}$. The structure was built at the National Institute for Astrophysics, Optics, and Electronics (INAOE) Tonantzintla, Puebla, Mexico and measurements were carried out by Dr. Edmundo A. Gutiérrez-Domínguez. Some results are shown in reference [33]. In the following analysis the investigated MAGFET has a $ W/L$ ratio of $ 0.8$ ( $ W = 100\,\mu$m and $ L = 125\,\mu$m) and a distance between the drains of $ 10\,\mu$m.

Figure 4.1: Two-drain MAGFET structure.
\includegraphics[width=120mm]{figures/fig401.eps}

Rodrigo Torres 2003-03-26