N type SOI lateral double-diffused metal-oxide semiconductor transistor

Abstract

A laterally double diffused metal oxide semiconductor transistor of an N-shaped silicon-on-insulator (SOI) comprises a semiconductor substrate. A buried oxide is arranged on the semiconductor substrate, an N-shaped doped semiconductor drift region is arranged on the buried oxide and a P-shaped well region is arranged above the N-shaped doped semiconductor drift region, and a field oxide, a metal layer, a gate oxide, a polysilicon gate and an oxide layer are arranged on the surface of the transistor. An N-shaped source region and a P-shaped contact region are arranged in a P-shaped well. The transistor is characterized in that the transistor also comprises at least a layer of floating oxide structure which is positioned in the N-shaped doped semiconductor drift region between a drain region and the buried oxide; moreover, a plurality of layers of floating oxide structure are allowed to further optimize the distribution of longitudinal electric fields in the drain region, thereby increasing the entire breakdown voltage of the transistor.

Description

technical field [0001] The present invention relates to the field of power semiconductor devices, and more particularly relates to a new structure of a silicon-on-insulator lateral double-diffused metal-oxide-semiconductor transistor (SOI LDMOS) suitable for high-voltage applications. Background technique [0002] Since the device made of silicon-on-insulator material can realize full dielectric isolation, its parasitic capacitance and leakage current are small, and the driving current is large, so it is very suitable for manufacturing power integrated devices and circuits. In order to make silicon-on-insulator devices work better, it is an important research topic to improve the breakdown voltage of silicon-on-insulator devices. As we all know, the withstand voltage of a silicon-on-insulator power device depends on the minimum of its lateral withstand voltage and vertical withstand voltage. The lateral withstand voltage of the device can be achieved by using bulk silicon ju...

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Problems solved by technology

However, it makes most of the insulating material layer have a large thickness, which is not conducive to the heat dissipation of the device, and also reduces the bonding strength. In addition, the etching of a large number of grooves also brings the complexity of the entire manufacturing process.

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