A silicon carbide Schottky diode with high withstand voltage and a method for manufacturing the same

Abstract

The invention belongs to the technical field of manufacturing semiconductor devices, the invention relates to a silicon carbide Schottky diode with high withstand voltage, A semiconductor substrate comprises an N-type silicon carbide substrate and an N-type silicon carbide epitaxial layer, the upper part of the N-type silicon carbide epitaxial layer is provided with a plurality of spaced apart strip-shaped first P-type well regions and strip-shaped first N-type well regions, A plurality of stripe-shaped second P-type well regions and stripe-shaped second N-type well regions are arranged belowor on the lower surface of the stripe-shaped first P-type well region and the stripe-shaped first N-type well region respectively, and the stripe-shaped first P-type well region and the stripe-shapedsecond P-type well region are respectively at angles of 30 degrees to 90 degrees; A stripe-shaped second P-type well region with a certain angle with the stripe-shaped first P-type well region is arranged below the stripe-shaped first P-type well region, and the doping concentration of the stripe-shaped N-type well region in the stripe-shaped P-type well region is increased at the same time, the breakdown voltage of the device is greatly increased, and the surge current capability of the device is improved.

Description

technical field [0001] The invention relates to a diode and a manufacturing method, in particular to a high withstand voltage silicon carbide Schottky diode and a manufacturing method thereof, belonging to the technical field of manufacturing semiconductor devices. Background technique [0002] Power devices and their modules provide an effective way to realize the conversion of various forms of electric energy, and have been widely used in national defense construction, transportation, industrial production, medical and health and other fields. Since the first power device application in the 1950s, each generation of power devices has enabled more efficient conversion and use of energy. [0003] Traditional power devices and modules are dominated by silicon-based power devices, mainly thyristors, power diodes, power triodes, power MOSFETs and insulated gate field effect transistors, which have been widely used in the full power range. History, very mature design technology...

AI Technical Summary

Problems solved by technology

At present, most silicon carbide diodes use junction barrier Schottky diodes (JBS), such as figure 1 Shown is a typical silicon carbide JBS structure. When the device is under normal withstand voltage, the PN junction formed by the P-type well region and the N-type epitaxial layer disperses the electric field near the Schottky barrier, making it difficult to break down the Schottky barrier. , but the existence of the PN junction reduces the current conduction area of ​​the device and increases the forward conduction voltage drop of the device

If the P-well with a larger pitch is used, the withstand voltage efficiency of the device will be further reduced, and a SiC device with high withstand voltage cannot be realized.

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