Front electrode structure of schottky diode and process manufacturing method of front electrode structure

Abstract

The invention discloses a process method for a front electrode of a schottky diode and an electrode structure of the front electrode structure. Besides the normal steps of extending, oxidizing, photoetching for the first time, injecting boron, annealing, photoetching for the second time, etching by using silicon dioxide, depositing a potential barrier, alloying the potential barrier and etching the potential barrier, the method also comprises the following steps of: washing, and evaporating metal Ti (titanium) or V (vanadium) on a contact layer, metal Ni (nickel) on a transitional layer, metal Al (aluminum) on a blocking layer, metal Ni (nickel) on the transitional layer, and metal Ag (argentum) on a conductive layer sequentially in vacuum so as to form a front electrode structure with the electrode metal Ag, Ni, Al, Ni, Ti or V. The invention has the advantages that: during welding or encapsulation, the damage to the silicon surface of an instrument can be reduced under the stress blocking action of Al; a welding pull force and the electro-static discharge resistance of the front electrode structure are improved remarkably.

Description

technical field [0001] The invention relates to the technical field of semiconductor chip manufacturing, in particular to a front electrode structure of a Schottky diode device and a front welding packaging process. Background technique [0002] Through vacuum evaporation or sputtering coating technology, deposit one or more layers of metal film on the front of the diode chip, as the main welding material, it provides a good welding platform for the subsequent packaging process, and has good characteristics of current conduction and heat conduction; [0003] The front electrode structure of the conventional Schottky diode chip is mostly composed of a three-layer structure such as Ti (titanium)-Ni (nickel)-Ag (silver), V (vanadium)-Ni (nickel)-Ag (silver). The voltage dividing ring and the main junction of the planar high-voltage transistor are formed at the same time. The main steps are: cleaning the Schottky diode chip before vacuum evaporation coating, vacuum evaporating c...

AI Technical Summary

Problems solved by technology

[0005] The formation process of the interface between the solder interface and the upper surface of the bottom metal is accompanied by the process of melting and re-solidification of various metals. The stress generated by this process is easily transmitted to the silicon surface of the device through the bottom metal, due to Schott The base diode is a surface device, so the stress will damage the device to a certain extent, and its physical and electrical characteristics will cause a certain degree of adverse effects, resulting in low packaging yield, poor solderability, and poor reliability.

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