Power schottky device barrier method

Abstract

Characters of the method includes following steps: (1) oxidation; (2) first photo etching; (3) boron diffusion; (4) second photo etching; (5) sputtering barrier metal; (6) vaporizing multilayer of metal on face side; (7) third photo etching; (8) annealing; (9) thinning rear face; (10) vaporizing multilayer of metal on rear face; (11) alloying (12) testing and cutting to separate slices. Useful effects are: reducing influences from surface state, enhancing forward and backward characteristics as well as capability of inverted voltage resistant and anti burning, preventing oxidation of metal layer prolonging service life, avoiding interdiffusion between each metal and silicide, raising fatigue resistance, and reinforcing stability of parts.

Description

(1) Technical field [0001] The invention relates to a power schottky barrier diode chip manufacturing technology, in particular to a power schottky device potential barrier method. (2) Background technology [0002] Power Schottky devices are not only widely used in electronic information fields such as communications, computers, and automobiles, but also used in key national defense projects such as aviation and aerospace. Waste of electric energy, the electrical parameters of power Schottky devices mainly include: forward voltage drop, reverse voltage, reverse leakage, etc. Schottky devices produced by existing technology have the following disadvantages: [0003] 1. The traditional metal-semiconductor contact has a great influence on the surface state, and the forward characteristics, reverse characteristics, reverse withstand voltage and anti-burnout capabilities of the device are poor. [0004] 2. The annealing temperature is poorly controlled, which affects the perfor...

AI Technical Summary

Problems solved by technology

[0003] 1. The traditional metal-semiconductor contact has a great influence on the surface state, and the forward characteristics, reverse characteristics, reverse withstand voltage and anti-burnout capabilities of the device are poor

[0004] 2. The annealing temperature is poorly controlled, which affects the performance of metal silicide

When impurity contaminants are present in oxygen and water vapor, an oxide layer will form on the upper surface of the silicide, causing side effects and also causing poor adhesion and poor electrical contact

Lack of measures to remove oxygen and moisture

[0005] 3. Using a single-layer metal electrode, for devices with high current density and high junction temperature, due to poor contact, it will degrade during operation, resulting in short device life

[0006] 4. The etching of multi-layer metal is a more prominent process difficulty for Schottky diodes

When etching multilayer metal, if the surface of the die is damaged (including pinholes, undercutting, etc.), the upper electrode alloy is easy to permeate and diffuse, resulting in the failure of the barrier junction, which seriously affects the electrical parameters and reliability of the device. Therefore, it is necessary to seek the best corrosion solution for each layer of metal

[0007] 5. The selection and preparation method of the barrier metal is not good, so that the uniformity, repeatability and step coverage of the barrier metal, and the mechanical adhesion between the metal film and the substrate are poor

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