Super-junction power device and fabrication method thereof

Abstract

The invention relates to a super-junction power device and a fabrication method thereof. The super-junction power device comprises an active region, a voltage division region, a cutoff ring region and a scribing channel region, wherein the voltage division region is arranged at the periphery of the active region, the cutoff ring region is arranged at the periphery of the active region, the scribing channel region is arranged at the periphery of the cutoff ring region, a plurality of P posts at the same interval are formed in the voltage division region, and the widths of the P posts in a direction from the active region to the cutoff ring region are gradually reduced. With the super-junction power device provided by the invention, the influence of an electric field accumulated on the surface of an oxide layer on the voltage division region can be reduced, meanwhile, the surface breakdown strength of the super-junction power device is improved, the area of the voltage division region is reduced, the performance of the device is improved, and the manufacturing cost of the device is reduced.

Description

technical field [0001] The invention relates to a power device, in particular to a super junction power device and a manufacturing method thereof. Background technique [0002] Vertical Double Diffused Field Effect Transistor (VDMOS for short) is a new power semiconductor device with rapid development and wide application. It introduces a super junction (Super junction) structure on the basis of ordinary vertical double-diffused metal oxide semiconductors, so that it has VDMOS high input impedance, fast switching speed, high operating frequency, voltage control, good thermal stability, and simple drive circuit. advantage. Its two poles are on both sides of the device, so that the current flows vertically inside the device, increasing the current density, improving the rated current, and the on-resistance per unit area is also small. It is a very versatile power device. [0003] Field limiting ring technology is one of the most commonly used voltage divider structures in po...

AI Technical Summary

Problems solved by technology

There are often some impurities in the surface oxide layer of this structure, which leads to the generation of interface charges on the surface, which will have a great impact on the surface potential of super junction power devices, affect the voltage division effect, and reduce the breakdown voltage

At the same time, during the manufacturing process, the ion concentration on the surface of the P-pillar area will decrease after multiple thermal processes of the super-junction power device, which will affect the surface breakdown strength, reduce the breakdown voltage of the super-junction power device, and affect the device performance.

Images