A kind of semiconductor power device and its manufacturing method

Abstract

The invention discloses a trench metal oxide semiconductor field effect transistor device, which comprises a plurality of closed trench metal oxide semiconductor field effect transistor units surrounded by trench gates, forming a square or rectangular pattern in the active region. Closed cell structure. And in the terminal area of ​​the device, multiple trench rings with floating voltage are included to improve the breakdown voltage of the device.

Description

technical field [0001] The invention relates to a unit structure of a semiconductor power device, a device structure and a manufacturing method. In particular, it relates to a novel cell structure, device structure and improved manufacturing method of a trench metal oxide semiconductor field effect transistor. Background technique [0002] As the cell density of semiconductor power devices increases, new device structures are urgently needed to reduce source-drain resistance (Rds). At the same time, in order to make semiconductor power devices have a wider application range, the reduction of Rds cannot be at the expense of sacrificing the reliability of the device and reducing the breakdown voltage. Conventional design techniques and device structures become extremely challenging to meet the above requirements, especially as the cell density of semiconductor power devices exceeds 600 million per square inch. [0003] In U.S. Patent No. 6,462,376, a DMOS (double-diffused me...

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Problems solved by technology

[0004] In addition, there is another disadvantage in this prior art: since both the n+ doped region and the p-type body region are formed before the trench gate, when the cell density of the device exceeds 112 million cells per square inch (that is, the device When the cell pitch is reduced to 2.4 microns), the punch-through problem is almost inevitable

Boron accumulated near the channel region will lead to a decrease in the doping concentration of the channel region, which in turn increases the possibility of channel region punch-through under reverse bias of the drain source

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