A deep ditch groove high-power MOS device and the corresponding manufacturing method

Abstract

The invention relates to a deep trench high-power MOS device and the manufacturing method. The MOS device is arranged on an overlooking plane, a central area is provided with an array which consists of parallel connected single cells, the periphery of the single-cell array is provided with a terminal protection structure, the terminal protection structure consists of at least one protection ring which is arranged at an inner ring and a stop ring which is positioned at an outer ring; as both the protection ring and the stop ring adopt trench type conductive polysilicon, and a single-cell grid electrode lead wire adopts the method of directly opening a hole to lead the wire on the trench type conductive polysilicon in the manufacturing process of the device; compared with the manufacturing method of existing common plane type deep trench high-power MOS device with a field-plate structure, the invention can reduce two lithographys and corresponding processes under the premise of not affecting the performances of the device, thus greatly reducing manufacturing cost. At the same time, the invention adopts one time phosphorus injection, then one time boron injection and matching annealing processes are adopted to regulate the conductive polysilicon resistance, thereby greatly reducing the leakage current between a grid and a source and ensuring to obtain a reasonable threshold voltage under the premise of not increasing the concentration of an N-well.

Description

technical field [0001] The invention relates to a high-power MOS device and a manufacturing method thereof, in particular to a deep-groove high-power MOS device and a manufacturing method thereof. This MOS device adopts the structural design of the trench conductive polysilicon guard ring and the trench conductive polysilicon stop ring, which can be reduced without affecting the device performance (such as specific Rdson, withstand voltage, device capacitance, etc.) The number of photolithography plates, thereby reducing the manufacturing cost of the device. Background technique [0002] The basic requirement of modern deep-trench high-power devices is to be able to withstand high voltage and operate at high current. Among them, the deep trench MOSFET usually achieves high current operation by connecting a large number of trench MOS unit cells in parallel. However, for high-voltage deep trench MOSFETs, the surface potentials of the parallel unit cells located in the middle...

AI Technical Summary

Problems solved by technology

At present, the mass production capacity of unit cell pitch (Pitch) at home and abroad can reach 1.2um~1.7um, the corresponding groove size is 0.4um, and the alignment accuracy requirement of stepper lithography machine is + / -0.12um, 0.9um The ~1.1um unit cell pitch (Pitch) process is under development, and further downward extension will be limited by the limit of the lithography machine process. At the same time, there will be problems such as increased device capacitance, resulting in reduced device switching speed.

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