LDMOS device and preparation method thereof

Abstract

The invention relates to an LDMOS device, which comprises a substrate, a drift region located in the substrate, a plurality of grooves arranged at intervals and located in the drift region, a plurality of metal field plates respectively positioned in the grooves, and an isolation dielectric layer at least located between the metal field plate and the inner wall of the groove. The grooves arranged at intervals enable the metal field plate to effectively go deep into the drift region, so that a multi-dimensional depletion effect is formed, meanwhile, the drift region between the grooves arranged at intervals reserves a carrier channel on the surface of the drift region, carriers of the LDMOS device basically flow along the surface of the drift region, and compared with the current carrier bypassing the groove along the side wall of the groove and the bottom wall of the groove, the motion path of the current carrier is shorter, and the on-resistance of the LDMOS device can be effectively reduced.

Description

technical field [0001] The invention relates to the field of semiconductors, in particular to an LDMOS device and a preparation method thereof. Background technique [0002] With the rapid development of power integrated circuits, the research and development of power semiconductor devices is becoming more and more important. For LDOMS (laterally diffused metal oxide semiconductor) devices, in order to improve the depletion ability of the drift region of LDMOS devices, the existing LDMOS devices Generally, trenches are dug in the drift region and a metal hole field plate is formed in the trench, and the metal field plate and the source are interconnected to deplete the drift region of the LDMOS device, thereby forming a multi-dimensional depletion to the best of effect. However, due to the introduction of the trench structure in the above solution, the distance for the carriers to flow from the source to the drain increases, resulting in an increase in the on-resistance (Ro...

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Problems solved by technology

However, due to the introduction of the trench structure in the above scheme, the distance for the carriers to flow from the source to the drain increases, resulting in an increase in the on-resistance (Ron), resulting in a limited reduction in the on-resistance of LDMOS.

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