Novel Lateral Double-Diffused MOSFET With Ultralow On-Resistance by the Variable Resistivity of Drift Region
Yandong Wang, Baoxing Duan, Haitao Song, Yintang Yang
Abstract
In power devices, the resistance of the drift region is the main factor for determining the performance. To reduce the on-resistance, a novel lateral double-diffused MOSFET with variable resistivity of the drift region (VR LDMOS) is proposed in this letter. In the off state, the low doping concentration in the drift region is used to obtain high resistivity to support the reverse voltage. In the on state, the resistivity is significantly reduced by introducing electrons. This is different from the constant resistivity in the drift region of the conventional LDMOS. Ultralow onresistance is obtained by the variable resistivity of the drift region. The simulation results show that the on-resistance is greatly reduced from 28.9mΩ·cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> of the conventional LDMOS to 1.5 mΩ·cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> of the VR LDMOS, which is almost 95% lower with the same 228 V breakdown voltage. Moreover, the current density is also been improved, which is 5 times higher than that of the conventional LDMOS.