A power diode device

Abstract

A power diode device belongs to the field of semiconductor power devices. Its cell structure includes cathode metal, N+ semiconductor substrate and N-semiconductor drift region arranged in sequence from bottom to top, and trench structures are symmetrically arranged on both sides of the top layer of N-semiconductor drift region. The trench structure includes bottom-up arrangement P+ semiconductor protection layer and polysilicon, anode metal is set on the upper surface of the N-semiconductor drift region between the trench structure and the trench structure; the cathode metal forms an ohmic contact with the N+ semiconductor substrate, the anode metal forms an ohmic contact with the polysilicon gate, and the anode metal A Schottky contact is formed with the N-semiconductor drift region, and a polysilicon gate forms a heterojunction with the N-semiconductor drift region. The invention has the characteristics of high forward current density, high reverse withstand voltage capability and low reverse leakage.

Description

Technical field[0001]The invention belongs to the field of power semiconductor device technology, and specifically relates to a power diode device structure.Background technique[0002]The development and efficient use of energy resources are the eternal theme of human development. Since human history entered the 21st century, the world's energy production and consumption have still been dominated by fossil energy. Considering the current development and utilization of energy resources, fossil energy will still be the energy basis for human survival and development for a long time. However, fossil energy will eventually be exhausted, and it is easy to cause environmental pollution. The resulting environmental and sustainable development issues are problems that mankind must face. Electricity is one of the main forms of human available energy, and the improvement of its use efficiency is an important solution to the world's energy problems. The power system is a necessary way for human...

AI Technical Summary

Problems solved by technology

[0006] Aiming at the problems of poor high-temperature reliability of Schottky junction, low reliability of gate oxide layer, large reverse leakage and low reverse withstand voltage of the above-mentioned traditional Schottky barrier diodes, the present invention proposes a power diode device and its fabrication method, the forward current level of the device is improved by forming a heterojunction between the first polysilicon 2 and the N-semiconductor drift region 4; the P+ semiconductor protective layer 7 at the bottom of the first polysilicon 2 is connected with the device when the device is reversely blocked. The depletion region formed by the N-semiconductor drift region 4 just cuts off the conductive channel and terminates the electric force line from the N-semiconductor drift region 4, thereby protecting structures such as trench gates and Schottky junction contacts, and improving device voltage blocking ability, improving the reliability of the gate oxide layer;

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