Semiconductor device and manufacture method thereof

Abstract

The invention discloses a semiconductor device having a trench structure. A surface of an N-type conductive semiconductor material is provided with trenches, an entire area of an upper part of the semiconductor material between the trenches is a P-type conductive material area, and a passivation layer is disposed on an upper surface of the P-type conductive material area. The P-type conductive material area is also disposed in the semiconductor material on corners of trench bottom edges. And Schottky barrier junctions are disposed on side walls of the trenches and surfaces of a bottom N-type conductive semiconductor material. The invention also provides a manufacture method for the semiconductor device, and through the manufacture method, a rapid-recovery diode can be made by twice photolithography technique.

Description

Technical field [0001] The invention relates to a semiconductor power device, in particular to a semiconductor device with a trench structure; the invention also relates to a manufacturing method of a semiconductor device. Background technique [0002] Power semiconductor devices are widely used in power management and power applications. Especially semiconductor devices involving trench structures have become an important trend in device development. Schottky devices have the advantages of low forward turn-on voltage and fast turn-on and turn-off speed. At the same time, Schottky devices also have the disadvantages of large reverse leakage current and cannot be used in high-voltage environments. [0003] BJ Baliga, the inventor of junction barrier Schottky, proposed a trench structure Schottky device in 1993, Trench Schottky Barrier Schottky (L.Tu and BJBaliga, USPatent#5,262,668, Issued November 16, 1993.) ,Such as figure 1 As shown, the surface of the device is a trench structu...

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Problems solved by technology

However, when this structure is reverse biased, although the inner wall of the trench uses a high barrier Schottky junction, the electric field strength in the semiconductor body at the corner of the bottom edge of the trench is easily affected by the shape of the trench and is too large, resulting in a reverse reaction of the device. At the same time, in the Schottky junction formation process, the deposited barrier metal is easy to form a void at the corner of the bottom of the trench, so the Schottky barrier junction cannot be formed here, thus affecting Device electrical parameters and reliability

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