Method for depositing metal electrode

Abstract

The invention discloses a method for depositing a metal electrode. The method comprises the steps of evaporating a bottom film on the surface of a wafer; coating a double-layer photoresist layer on the surface of the wafer, wherein the double-layer photoresist layer covers the bottom film; and performing exposure and development on the double-layer photoresist layer so as to display a specific deposition pattern; performing first metal deposition and second metal deposition on the deposition pattern in sequence; depositing third metal for multiple times on the second metal layer at different rates; and removing the photoresist layer on the surface of the wafer so as to form a metal electrode pattern on the surface of the wafer. The shape of the photoresist can be well maintained in a modeof matching the deposition with different deposition rates, thereby preventing a problem that the photoresist deforms and collapses under the bombardment of high-energy atoms for a long time, and solving a problem of difficult metal stripping.

Description

technical field [0001] The invention relates to the field of semiconductor optoelectronic technology, in particular to a method for depositing metal electrodes. Background technique [0002] Metal electrode deposition methods are widely used in semiconductor and micro-nano technology, usually there are electron beam evaporation physical deposition methods and electrochemical methods. The electron beam evaporation method has a good vertical incident direction, and better adhesion between the metal and the semiconductor can be obtained, thereby forming a metal circuit on the surface of the laser chip. When making the front electrode (p-electrode) on the surface of the laser chip, it is necessary to perform a yellow light process to expose specific circuit channels, and then use metal deposition to grow gold. [0003] In the metal deposition process with a photoresist mask, a double-layer photoresist is generally used to form a double-layer undercut structure instead of a sing...

AI Technical Summary

Problems solved by technology

However, when electron beam evaporation deposits > 2um metal, when only one deposition rate is used to achieve the target deposition thickness, regardless of the single-layer photoresist structure or the double-layer photoresist structure, under the influence of metal stress and temperature, the thickness will be different to varying degrees. photoresist distortion

For example: when metal is deposited at a low deposition rate, the metal deposition time is too long, the production efficiency is low, and the production cost is too high. The bombardment of the photoresist by high-energy atoms at a high rate will cause the photoresist to collapse, make metal stripping difficult, and cause metal curling problems

Images