High temperature lift-off process
AssigneeInternational Business Machines Corporation
InventorRosemary A. Previti-Kelly
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Abstract
Disclosed is a process for forming a pattern of metallization on a processed semiconductor substrate, under high temperature conditions, employing a polyimide precursor material as a lift-off layer. Advantageously, the material is photosensitive, and, after exposure and development, the portions of the layer remaining on the substrate can be completely and readily removed with conventional solvents.
Claims10
A process for forming a pattern of conductive material on a processed semiconductor substrate, comprising the steps of:
- applying a layer of photosensitive polyimide precursor to said substrate, wherein said precursor is a material which fully imidizes at a temperature in excess of the temperature at which said conductive material is to be applied, said layer having a thickness greater than about 15.mu. and at least about 25% greater than that of said film to be formed;
- imagewise exposing and then developing said layer so as to uncover portions of said substrate;
- applying a conductive material to form a film on the portions of said layer remaining on said substrate and the uncovered portions of said substrate at a temperature in the range from about 150.degree. C. to about 250.degree. C.;
- and
- lifting-off said remaining portions of said layer and the portions of said film which overlie said remaining portions of said layer.
A process for forming a pattern of metallization on a processed semiconductor substrate, comprising the steps of:
- applying a layer of photosensitive polyimide precursor to said substrate, wherein said precursor is a material which fully imidizes at a temperature in excess of the temperature at which metal is to be deposited, said layer having a thickness greater than about 15.mu. and at least about 25% greater than that of a metal film to be deposited;
- imagewise exposing said layer of photosensitive polyimide precursor;
- immersing said substrate in a developer so as to remove the unexposed portions of said layer and to uncover portions of said substrate;
- depositing a metal film on the portions of said layer remaining on said substrate and the uncovered portions of said substrate at a temperature in the range from about 150.degree. C., to about 250.degree. C.;
- and
- immersing said substrate in a solvent to lift-off said remaining portions of said layer and the portions of said metal film which overlie said remaining portions of said layer.
Dependencies are inferred from the claim text.