Method for stripping metal film by using positive photoresist as mask

Abstract

The invention discloses a method for stripping a metal film by using positive photoresist as a mask. Gluing, pre-baking, exposing, developing, cleaning, extensive exposing, metal plating and strippingare conducted on a substrate, specifically, a blue film is attached to the surface of the substrate, then the blue film is torn off, and metal with glue at the bottom is removed through the viscosityof the blue film. And finally, the substrate is placed in an organic solvent, and the residual photoresist on the surface of the substrate and the residual metal on the substrate are removed. According to the invention, the traditional positive photoresist is adopted, the normal exposure energy and exposure time of the positive photoresist are used in a photoetching machine to carry out whole-surface extensive exposure, and then film coating is carried out. Extensive exposure is performed on the positive photoresist; the photoresist crosslinking is changed, the adhesion is reduced, chain scission reaction occurs between molecules, pinholes are formed in the surface of the photoresist, so that the adhesion between the metal film and the surface of the positive photoresist becomes poor, themetal layer with the photoresist at the bottom can be directly torn off by using the blue film, and the defect that metal with a right angle or an approximate right angle after positive photoresist development is not easy to lift off is overcome.

Description

technical field [0001] The invention relates to a method for peeling off a metal film by using a positive resist as a mask, and belongs to the field of semiconductor chip processing. Background technique [0002] It is a very valuable technology to make fine metal patterns by lift-off technology in the range of micron and submicron. The basic sequence of lift-off technology is to first coat one or more layers of negative photoresist on the surface of a clean substrate, and after performing different processes such as pre-baking, exposure, post-baking, and developing, an inverted trapezoidal photolithography is obtained on the surface of the substrate. The cross-sectional geometry of the glue side, and then deposit a metal layer on the surface of the substrate by evaporation or sputtering, and finally peel off the photoresist and the metal on it, while the metal layer in close contact with the substrate remains. [0003] Stripping techniques are generally divided into negati...

AI Technical Summary

Problems solved by technology

This kind of graphic reversal glue is more expensive and the process increases

Not suitable for mass production of chips

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