Grooved Schottky device structure and manufacturing method thereof

Abstract

The invention provides a grooved Schottky device structure and a manufacturing method thereof. The grooved Schottky device comprises an N-type heavily-doped substrate, an N-type lightly-doped silicon epitaxial layer, at least two grooves, N-type highly-doped polycrystalline silicon layers, a metal silicide layer, a positive electrode and a negative electrode, wherein the N-type heavily-doped silicon epitaxial layer is formed on the substrate; the grooves are formed in the silicon epitaxial layer; a first silicon dioxide layer, a middle medium layer and a second silicon dioxide layer are formed in sequence on the surface of each groove; the N-type highly-doped polycrystalline silicon layers are filled into the grooves; the metal silicide layer is formed on the surface of the silicon epitaxial layer; the positive electrode is formed on the surface of the metal silicide layer; the back electrode is formed on the back surface of the N-type heavily-doped substrate. According to the grooved Schottky device structure, a first silicon dioxide layer / middle medium layer / second silicon dioxide layer compound structure is taken as a groove medium layer, so that the leakage current can be reduced remarkably, the requirement on the increase of the breakdown voltage and the reduction of the leakage current are met, a narrow groove structure can be adopted, the Schottky potential barrier contact area is increased, and the positive break-over voltage is lowered.

Description

technical field [0001] The invention belongs to the field of semiconductors, and relates to a groove type Schottky device structure and a manufacturing method thereof. Background technique [0002] The power Schottky device is a semiconductor two-terminal device used for large current rectification. The commonly used power Schottky device is made of the Schottky junction between metal silicide and low-doped N-type silicon. Metal silicide The compound can be platinum-silicon compound, titanium-silicon compound, nickel-silicon compound and chromium-silicon compound, etc. In recent years, due to the development of trench technology, various trench structures have been used to make the leakage protection ring of the cell Schottky structure, such as the commonly used trench MOS structure. The adoption of the trench type MOS structure reduces the area of ​​the traditional PN junction protection ring, and when the chip area used by the device is the same, the forward conduction vo...

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Problems solved by technology

[0008] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a trench type Schottky device structure and a manufacturing method thereof, which are used to solve the problem of not being able to effectively control the Schottky reverse leakage and reduce the forward leakage in the prior art. The problem of conduction voltage drop

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