A method for manufacturing a grooved Schottky front silver surface metal structure

Abstract

The invention discloses a method for manufacturing a grooved Schottky front silver surface metal structure, the method comprising the following steps: a. forming a barrier metal layer on a silicon wafer to form a silicon wafer-barrier metal structure; b. Carry out the first heat treatment to the silicon wafer-barrier metal structure; c. form the first metal layer on the barrier metal layer to form the silicon wafer-barrier metal-first metal layer structure; d. Metal - the first metal layer structure is subjected to a second heat treatment; e. Depositing a second metal layer on the first metal layer. The present invention adopts suitable metal film thickness and alloy condition, adopts metal alloying before titanium-nickel-silver, can avoid the apparent abnormality of product; The shape is stable, which is conducive to the improvement of product reliability; this process is compatible with existing conventional processes, and does not require special equipment and the introduction of new photoresists.

Description

technical field [0001] The invention relates to a front silver surface metal technology, in particular to a method for manufacturing a grooved Schottky front silver surface metal structure. Background technique [0002] Schottky barrier diodes have been used in power supply applications for decades as rectifying devices. Compared with PN junction diodes, Schottky barrier diodes have the advantages of low forward turn-on voltage and fast switching speed, which makes them very suitable for switching power supplies and high-frequency applications. [0003] Schottky barrier diodes are manufactured using the principle of a metal-semiconductor junction formed in contact between a metal and a semiconductor. Trench Schottky adopts the principle that the trench structure produces a depletion layer to pinch off the conductive channel, and its high-frequency characteristics and electrical performance are significantly better than those of the planar Schottky. At present, the followin...

AI Technical Summary

Problems solved by technology

At present, the following methods are mainly used to manufacture the grooved Schottky front silver surface metal structure: first, use the lift off process to perform photolithography three times, and then evaporate or sputter metal on the surface of the photoresist, and use the film to remove the metal structure. The metal on the photoresist is peeled off by the film method, the process cost is high, a special photoresist is required, and there are problems such as metal residue when the film is peeled off; the second method is to perform a photoetching on the metal surface , and then etch the metal, the etched morphology is unstable, prone to over-etching and metal residues

[0004] The following problems occurred in the actual manufacturing of the grooved Schottky front silver surface metal structure: 1. Due to the existence of the grooves and the stress between the metal films, the warpage of the wafer is too large and the processing is difficult; 2. , The composite metal film is difficult to corrode, prone to over-etching and metal residues, and the corrosion morphology is as follows figure 1 The inverted triangle phenomenon is easy to appear, which directly affects the adhesion between metal films and product reliability

Images