Preparation method of TMBS device

Abstract

The invention relates to the technical field of semiconductor, in particular to a preparation method of a TMBS device. The preparation method comprises the following steps of: S1, providing a substrate which comprises an active area and a terminal protection area around the active area; S2, forming a metal silicide layer on the substrate exposed upper surface in the active area by adoption of a sputter deposition process and a hot annealing process; S3, removing metal residues on the upper surface of the metal silicide by adoption of a wet etching process, so as to form a prefabricated deviceconsisting of a substrate, a grating structure, a terminal protection ring and a metal silicide layer; S4, further removing the metal residues on the surface of the prefabricated device by adoption ofa cleaning process; S5, bombarding the surface of the prefabricated device by adoption of an ion injection process; and S6, sputtering a metal layer on the surface of the prefabricated device. The preparation method is capable of avoiding the influences, on the device, of the metal residues, and ensuring the stress of the metal silicide layer by utilizing the injection process, thereby solving the problem of metal peeling on wafers and making the contact resistance small.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a preparation method of a TMBS device. Background technique [0002] TMBS (trench MOS barrier Schottky rectifier trench metal oxide semiconductor barrier Schottky rectifier, referred to as TMBS) is a power device that introduces a trench MOS gate structure, and reduces the Schottky barrier by using the "charge coupling" effect. The electric field strength, thereby reducing the forward conduction voltage drop, while obtaining a lower reverse leakage current. In practical applications such as freewheeling diodes, smartphone chargers, and solar cells, the lower the forward voltage drop and reverse leakage current of TMBS, the lower the power loss and the higher the efficiency. Therefore, lower forward voltage drop and reverse leakage requirements are the current market orientation. [0003] In the actual manufacturing process, the selection of Schottky barrier metal, the fo...

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Problems solved by technology

Aqua regia, the acid solution used to corrode nickel-platinum metals, has strong oxidizing properties. When corroding nickel-platinum metals, it will also form a thin and dense oxide film on the surface of the silicide, and the chemical products produced during the corrosion process are easy to adhere to. On the surface of the wafer, it is also difficult to remove it in the subsequent flushing process; in addition, the side walls of the TMBS trench are prone to residual barrier metals. After that, the bonding ability with silicon will become poor, the stress will not match, the contact resistance will be large, and the residue position will easily produce cavities. In severe cases, metal peeling will occur. Therefore, the final device performance parameters are not ideal, and the consistency is very good. Poor or even outright failure

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