The New Structure and Analytical Model of a High-Voltage Interconnection Shielding Structure With High-k Dielectric Pillar

Abstract

The high-voltage interconnection (HVI) effect induces electric field crowding near the source region of power lateral double diffused metal oxide semiconductor field effect transistors (LDMOSs) and, therefore, weakens its breakdown voltage (BV) characteristic. To suppress such a detrimental effect, a novel HVI structure with a high- ${k}$ dielectric pillar beneath the HVI metal line is proposed. An analytical model is proposed to reveal the mechanism of the proposed structure and explain the effects of the parameters of the structure. The analytical model indicates that the high- ${k}$ dielectric pillar eliminates the electric field crowding near the source, promotes the depletion of the drift region, and avoids the premature breakdown. Meanwhile, due to the existence of the high- ${k}$ dielectric pillar, the surface electric field profile in the drift region can be modulated, and the influence of HVI can be effectively suppressed. Thus, a higher BV is obtained. The simulation results indicate that the proposed structure presents better BV, which is the same as that of the reduced surface field (RESURF) structure without HVI.