Technological method for manufacturing groove type Schottky diodes

Abstract

The invention discloses a technological method for manufacturing groove type Schottky diodes. Contact holes are particularly formed by means of etching by the aid of two-step dry processes. The technological method includes etching silicon surfaces at first when the contact holes are about to be formed; then etching silicon and silicon oxide in grooves together. Selection ratios of the silicon to the silicon oxide in last-step contact hole etching menus are 1:1, the silicon surfaces are etched by depths higher than 1000 angstroms approximately, the silicon oxide in the side walls of the grooves is protruded out of the silicon surfaces, and Schottky contact effects are ultimately realized by the aid of metal. The technological method has the advantages that the technological method aims to solve the problem of high electric leakage of existing groove Schottky diode products, the internal uniformity of the surfaces of products can be improved, the production cost can be reduced, the yield of the products can be increased, and the technological method is suitable for mass production on a large scale.

Description

technical field [0001] The invention relates to a manufacturing process of a semiconductor integrated circuit, in particular to a manufacturing process method of a trench Schottky diode. Background technique [0002] Schottky diodes are well known in the industry and are fabricated through a variety of different layout designs and processes. The trench-type layout typically shown in Baliga's US Patent No. 5,612,567 is also known. The trench-type Schottky diode pursues the maximization of the forward conduction current capability, and its mesa area is fully utilized in Schottky. The base barrier contacts, which requires the contact hole to fully open the cell area during etching. At present, the commonly used preparation method is to dry-etch the contact hole, and then directly deposit metal to form the Schottky contact, but the actual process will cause problems such as small process window, large reverse leakage current, and low product yield. Contents of the invention ...

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Problems solved by technology

At present, the commonly used preparation method is to etch the contact hole by dry method, and then directly deposit the metal to form the Schottky contact, but the actual process will cause problems such as small process window, large reverse leakage current, and low product yield.

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