Super junction power device and manufacturing method thereof

Abstract

A super junction power device disclosed by the invention comprises a substrate epitaxial layer of a first doping type, body regions of a second doping type, and JFET regions. The substrate epitaxial layer is internally provided with a drain region of the first doping type and a plurality of sidewall-sloped columnar epitaxial doped regions of the second doping type. The body regions are respectively arranged on the top ends of the columnar epitaxial doped regions, and each body region is internally provided with source regions of the first doping type. Each JFET region is disposed between every two adjacent body regions. A gate oxide layer is arranged on the body regions and the JFET regions. Gates are arranged on the gate oxide layer. Compensation injection regions are arranged in the substrate epitaxial layer at the two sides of the sidewalls and at the bottom of the columnar epitaxial doped regions. The breakdown voltage is increased and the reverse recovery characteristic is improved under the condition that the on resistance of the super junction power device is basically unchanged. The manufacturing process is simple and easy to implement.

Description

technical field [0001] The invention belongs to the technical field of semiconductor power devices, in particular to a super junction power device and a manufacturing method thereof. Background technique [0002] The super junction power device forms a plurality of columnar epitaxial doped regions in the substrate epitaxial layer. The columnar epitaxial doped regions and the substrate epitaxial layer have the opposite doping type. Between the columnar epitaxial doped regions and the substrate epitaxial layer Carriers are easy to deplete each other to increase the breakdown voltage of super junction power devices. In the prior art, the manufacturing method of super-junction power devices is usually to first grow one or two layers of substrate epitaxial layer, then form trenches in the substrate epitaxial layer, and then grow the substrate epitaxial layer material so that in the trench A columnar epitaxial doped region is formed inside. The technical disadvantage of the exis...

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Problems solved by technology

However, this technology has the following disadvantages. Since the sidewalls of the columnar epitaxial doped regions usually have inclined angles, the width of the bottom of the columnar epitaxial doped regions becomes smaller, thereby destroying the charge balance at the bottom of the columnar epitaxial doped regions. Impact ionization occurs first at the bottom of the epitaxial doped region, which reduces the breakdown voltage of super junction power devices

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