A kind of preparation method of tmbs device

Abstract

The present invention relates to the field of semiconductor technology, in particular to a method for preparing a TMBS device, comprising: step S1, providing a substrate having an active region and a terminal protection region surrounding the active region; step S2, using a sputtering deposition process and a thermal annealing process to form a metal silicide layer on the exposed upper surface of the substrate in the active region; step S3, using a wet etching process to remove the metal residue on the upper surface of the metal silicide layer to form a substrate, gate A prefabricated device of structure, terminal protection ring and metal silicide layer; Step S4, adopting a cleaning process to further remove metal residues on the surface of the prefabricated device; Step S5, adopting an ion implantation process to bombard the surface of the prefabricated device; Step S6 , sputtering a metal layer on the surface of the prefabricated device; it can avoid the influence of metal residues on the device, and at the same time, the implantation process is used to ensure the stress of the metal silicide layer, which solves the problem of metal peeling on the wafer, and the contact The resistance is 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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