Trench MOS barrier Schottky diode and manufacturing method

Abstract

Provided are a trench MOS barrier Schottky diode and a manufacturing method. The trench MOS barrier Schottky diode comprises a substrate, an epitaxial thin film manufactured on the substrate, a protective ring, an insulation dielectric film, Schottky contact metal, a first bonding block, ohmic contact metal and a second bonding block. A boss is arranged in the middle of the epitaxial thin film, and the side wall of the boss is a plane. The protective ring is manufactured on the periphery of the boss of the epitaxial thin film and is located below the plane on the periphery of the boss. The insulation dielectric film is manufactured on the side wall of the periphery of the boss of the epitaxial thin film, the height of the insulation dielectric film is flush with that of the boss of the epitaxial thin film, the insulation dielectric film is located on the protective ring, the height of the part, on the protective ring, of the insulation dielectric film is smaller than that of the surface of the boss, and the section of the insulation dielectric film is an L shape. The Schottky contact metal is manufactured on the surface of the insulation dielectric film and covers the surface of the boss of the epitaxial thin film. The first bonding block covers the surface of the Schottky contact metal. The ohmic contact metal is manufactured on the back face of the substrate. The second bonding block is manufactured on the back face of the ohmic contact metal and can further lower the power consumption of a carborundum power electronic device.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a trench type MOS barrier Schottky diode and a manufacturing method. Background technique [0002] Silicon carbide materials have the characteristics of wide band gap, high breakdown field strength, high thermal conductivity, high saturation electron migration rate, and excellent physical and chemical stability. It is very suitable for working in high temperature, high frequency, high power and extreme environments. Silicon carbide Schottky diodes were the first devices to be commercialized. Devices below 1000V generally adopt the structure of Schottky Barrier Diodes (Schottky Barrier Diodes-SBD), and devices above 1000V generally adopt the structure of Junction Barrier Schottky Diodes (JBS). [0003] The traditional trench MOS barrier Schottky diodes (Trench MOS Barrier Schottky Diodes-TMBS) were first used to reduce the on-state resistance of the silicon-based Schottky...

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Problems solved by technology

However, when this traditional TMBS structure is applied to silicon carbide power electronic devices, since the critical breakdown electric field strength of silicon carbide material is ten times that of silicon, the insulating dielectric film in the trench is usually under reverse bias of the device. Breakdown occurs earlier than silicon carbide, which greatly reduces the withstand voltage capability of the device

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