High temperature lift-off process

Claim 2

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 15μ 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° C. to about 250° C.; and lifting-off said remaining portions of said layer and the portions of said film which overlie said remaining portions of said layer.

Claim 3

The process of claim 1, wherein said photosensitive polyimide precursor material has the formula ##STR3## wherein R is ##STR4##

Claim 4

The process of claim 1, wherein said film of conductive material is formed at a temperature in the range from about 165° C., to about 200° C.

Claim 5

The process of claim 3, wherein said layer of photosensitive polyimide precursor has a thickness of about 15-30μ and said film of conductive material has a thickness of about 12-18μ.

Claim 6

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 15μ 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° C., to about 250° 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.

Claim 7

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 15μ 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° C., to about 250° 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.

Claim 8

The process of claim 5, wherein said photosensitive polyimide precursor material has the formula ##STR5## wherein R is ##STR6##

Claim 9

The process of claim 6, wherein said metal film is formed at a temperature in the range from about 165° C., to about 200° C.

Claim 10

The process of claim 1, wherein said layer of photosensitive polyimide precursor has a thickness of about 15-30μ and said film of conductive material has a thickness of about 12-18μ.

Claim 11

The process of claim 8, wherein said solvent comprises n-methyl pyrrolidone.

Claim 12

The process of claim 1, wherein said photosensitive polyimide precursor fully imidizes at a temperature of at least about 250°-280° C.