Enhancement of Electrical Safe Operation Area of 60 V nLDMOS by Engineering of Reduced Surface Electrical Field in the Drift Region.

To enhance the electrical safe operation area (eSOA) of laterally diffused metal oxide semiconductor (LDMOS) transistors, a novel reduced surface electric field (Resurf) structure in the n-drift region is proposed, which was fabricated by ion implantation at the surface of the LDMOS drift region and by drift region dimension optimization. Technology computer-aided design (TCAD) simulations show that the optimal value of Resurf ion implantation dose 1 × 10¹² cm⁻² can reduce the surface electric field in the n-drift region effectively, thereby improving the ON-state breakdown voltage of the device (BV_on). In addition, the extended n-drift region length of the L_d design also improves device BV_on significantly, and is aimed at reducing the current density and the electric field, and eventually suppressing the n-drift region impact ionization. The results show that the novel 60 V nLDMOS has a competitive BV_on performance of 106.9 V, which is about 20% higher than that of the conventional one. Meanwhile, the OFF-state breakdown voltage of the device (BV_off) of 88.4 V and the specific ON-resistance (R_ON,sp) of 129.7 mΩ⋅mm² exhibit only a slight sacrifice. [ABSTRACT FROM AUTHOR]