A kind of semiconductor rectifier and its manufacturing method

Abstract

The invention discloses a semiconductor rectifier. The semiconductor rectifier comprises a first conductive type of light-doped epitaxial layer, wherein a plurality of grooves are transversely formed in the upper part of the epitaxial layer at intervals, the first grooves are filled with conductive poly-silicon, isolation layers are arranged between the conductive poly-silicon and the first grooves and upwards protrude to form dielectric walls, conductive poly-silicon side walls are arranged on the two sides of the dielectric walls, a second groove is formed in a region between the upper part of the epitaxial layer and the conductive poly-silicon side walls, a transverse uniform doping region and a gradient doping region are arranged at the upper part of the epitaxial layer, channels are formed between the gradient doping region and the isolation layers, and isolation regions are arranged among the lower part of the epitaxial layer, the transverse uniform doping regions, the gradient doping regions and the isolation layers. With the adoption of a groove grid structure, the semiconductor rectifier has the characteristics of short channel and channel doping gradient distribution and excellent positive conduction. The invention also discloses a fabrication method of the semiconductor rectifier, and the process is simple in step, large in process window, few in photoetching frequency and low in fabrication cost, and is easy to control.

Description

technical field [0001] The invention relates to the technical field of semiconductor device manufacturing, in particular to a semiconductor rectifier and a manufacturing method thereof. Background technique [0002] As a conversion device of electric energy, semiconductor rectifiers have higher and higher requirements for performance improvement such as reducing forward voltage drop, increasing reverse blocking voltage, reducing reverse leakage, and increasing switching speed for the sake of improving system efficiency. . [0003] The PN junction diode used as a semiconductor rectifier earlier, due to the need to overcome the PN junction barrier during forward conduction, resulting in high forward conduction voltage drop, and the low switching speed caused by minority carrier injection during forward conduction, has been adopted by SCHOTT in many application fields. base barrier diodes instead. Schottky barrier diodes are usually composed of an N-type epitaxial layer with ...

AI Technical Summary

Problems solved by technology

However, due to the limitations of the methods for forming short channels and channel doping gradient distribution, such devices are usually based on a planar gate structure, and there are junction field effect transistors formed by parasitic body doping regions inside the device, and the parasitic junction field effect transistors increase The series resistance on the conductive channel is increased, and at the same time, the increase of the conductive channel density is limited; in order to avoid the possible punch-through leakage caused by the short channel when the device is reverse biased, the doping concentration of the epitaxial layer is usually low, which further increases the Series resistance on the conduction channel; the above two points make the forward conduction voltage drop of the device at high current higher, usually higher than that of trench Schottky barrier diode

[0005] It can be seen that the prior art still has deficiencies in the forward conduction voltage drop of semiconductor rectifiers, and it is of great significance to further improve the device structure and manufacturing method

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