Experiments of Homogenization Field LDMOS with Trench-Stopped Depletion

A homogenization field lateral double diffused metal oxide semiconductor based on the trench-stopped depletion (TS-HOF LDMOS) is proposed and experimentally realized in this article. By solving the 3-D Poisson equation, the curvature factor ${k}$ is introduced to give the quantitative relationship between the maximum field ${E}_{\text {max}}$ and parameters of the 3-D bulk curvature effect. Based on the theory, the trench-stop concept and the TS-HOF structure were proposed to reduce ${E}_{\text {max}}$ . In the new structure, the depletion of the last discrete metal insulator semiconductor (MIS) array is stopped by process compatible drain trenches for suppressing the serious 3-D bulk curvature effect especially at high voltage, which is a special technology for improving breakdown voltage ${V}_{\text {B}}$ of the complementary homogenization field (C-HOF) LDMOS. It was demonstrated by experiments that ${V}_{\text {B}}$ of the TS-HOF LDMOS is more than 15% higher than that of the C-HOF device while maintaining the same specific ON-resistance ${R} _{\text {on,sp}}$ . The TS-HOF LDMOS achieved a measured ${V}_{\text {B}}$ of 675 V and a ${R} _{\text {on,sp}}$ of 49.1 $\text{m}\Omega \,\cdot $ cm2, which represents a reduction of 43.2% when compared with the theoretical value of the triple reduced surface field (RESURF) technology.