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 comprises the following steps: a. Carrying out the first photolithography on the metal layer of the Schottky device: coating, exposing, Development; b. Etching metal for the first time, etching part of the metal in the metal layer, and removing glue; c. Second photolithography: coating, exposure, and development to protect the corroded part of the metal; d. Etch the metal twice, etch the remaining metal in the metal layer, and remove the glue. The present invention adopts the method of photoetching twice and corroding the multi-layer metal thin film twice, which can stabilize the corroded appearance of the metal. When the metal surface is subjected to tension, it is not easy to warp and fall off, which is beneficial to the improvement of product reliability; at the same time, This process is compatible with existing conventional processes, without the need for special equipment and the introduction of new photoresists, effectively reducing manufacturing costs.

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...

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Problems solved by technology

At present, the following methods are mainly used to manufacture trench Schottky barriers: the first method is to 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 method of sticking and peeling off the film The metal on the photoresist is peeled off, the process cost is high, a special photoresist is required, and there are problems such as metal residue when peeling off the metal; the second method is to perform a photolithography on the metal surface, and then engrave Etching its metal, its etched morphology is unstable, prone to over-etching and metal residues

[0004] The following problems occur in the actual manufacture of the grooved Schottky barrier: 1. Due to the existence of the groove and the stress effect between the metal films, the warpage of the wafer is too large and the processing is difficult; 2. The composite metal It is difficult to corrode the film, and it is 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

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