5.3.3 Bias Dependence

The relative sensitivity of the three-drain MAGFET is shown in Figure 5.10 as a function of the gate voltage for different drain voltages at 77 K. As expected, the simulation results show that the three-drain MAGFET has a higher relative sensitivity at 77 K than at 300 K. However, the improvement in the relative sensitivity is not as high as in the two-drain MAGFET analysis, where a maximum of almost 55 % T$^{-1}$ can be reached whereas a maximum of 40 % T$^{-1}$ for the three-drain MAGFET is achieved. A plausible explanation is that the central current at Drain 2 is higher as the drain currents at Drain 1 and Drain 3, decreasing the relative sensitivity.

Figure 5.10 shows an important detail. Except from the plot where the drains are set to 0.1 V, in the other plots the relative sensitivity shows an increasing behavior while increasing the lateral electric field. A possible explanation is that the three-drain MAGFET at 77 K and at 0.1 V at the drains experiences both drift and diffusion of carriers in the inversion channel.

Figure 5.10: Simulated $S_r$ as a function of the gate voltage at 77 K and -50 mT.

Figure 5.11 shows the relative sensitivity of the three-drain MAGFET as a function of the drain voltage for different gate voltages at 77 K. Compared with Figure 4.86, both Figures show the same shape. Once again, the improvement is not as high as in the two-drain MAGFET. The high central current at Drain 2 explains the lower improvement in the relative sensitivity.

Figure 5.11: Simulated $S_r$ as a function of the drain voltage at 77 K and -50 mT.