US 4,045,594 A · Planar insulation of conductive patterns by chemical vapor deposition and sputtering

Abstract

A method using a chemically vapor deposited (CVD) insulator to form a substantially planar layer of insulative material atop a conductive pattern on the surface of a substrate. The invention also features the use of a photoresist both as a mask for forming apertures in an underlying insulating layer as well as a lift-off material for a subsequently deposited conductive layer. In the method, a first insulating layer is deposited atop the substrate. Photoresist is then deposited; the resist pattern is exposed and developed; and the insulator is etched to expose selected areas of the substrate. A conductive film, preferably metal, is then deposited in blanket fashion in such quantity as to achieve the same height as the first insulator within the exposed apertures. The resist is lifted off, thereby leaving metal in the exposed apertures only. The pattern at this point consists of a single level of a conductive pattern and the insulator pattern with gaps between the conductors and the insulator. The gaps are the result of the unavoidable removal of a portion of the insulator below the photoresist during the etching process. Another insulating film is chemically vapor deposited (pyrolytically deposited) in blanket fashion. Notwithstanding the gaps between the conductors and first insulator, the second film is substantially planar if the thickness of this second insulating film equals or exceeds one-half the width of the largest of said gaps. The method is applicable to any level of conductive patterns (metallization) atop the substrate.

Claims28

Dependent claims

A method for forming a conductive pattern atop a substrate comprising:

forming a first insulating film on said substrate;
forming a masking layer of photosensitive material on said first insulating film, said masking layer having at least one aperture;
forming apertures in said first insulating film corresponding to said masking-layer apertures;
depositing a conductive film atop said masking layer and into said apertures, the surface of said conductive film in said apertures being substantially flush with the surface of said first insulating film;
said deposition resulting in gaps between said conductive film in said apertures and insulating film;
removing said masking layer, thereby leaving a conductive pattern in said apertures;
forming on said first insulating film and said conductive pattern a second insulating film by a chemical vapor deposition reaction;
said second insulating film having a thickness which is at least one-half that of the width of the largest of said gaps, whereby a substantially planar second insulating film is formed.

5 more elements

A method for forming multiple levels of conductive patterns atop a substrate comprising:

forming a first insulating film on said substrate;
forming a first masking layer of photosensitive material on said first insulating film, said masking layer having at least one aperture;
forming apertures in said first insulating film corresponding to said first-masking-layer apertures, thereby forming a first aperture pattern;
depositing a first conductive film atop said first masking layer and in said first aperture pattern, the surface of the conductive film in said apertures being substantially flush with the surface of said first insulating film;
said deposition resulting in gaps between said conductive film in said first apertures and said first insulating film;
removing said first masking layer, thereby leaving a first conductive pattern in said first aperture pattern;
forming on said first insulating film and said first conductive pattern a second insulating film of known thickness by a chemical vapor deposition reaction;
said second insulating film having a thickness which is at least one-half that of the width of the largest of said gaps, whereby a substantially planar second insulating layer is formed;
forming a third insulating film of known thickness on said second insulating film;
forming a second layer of photosensitive material on said third insulating film, said second photosensitive material having the property of maintaining its photosensitivity after being exposed once;
forming apertures corresponding to a second aperture pattern in said second photosensitive material by masking, exposing and developing said material;
forming apertures in said third insulating film corresponding to said second aperture pattern;
forming apertures corresponding to a third aperture pattern in said second photosensitive material by remasking, reexposing and redeveloping said material;
said third aperture pattern including the second aperture pattern;
forming apertures in said second and third insulating films corresponding to said third aperture pattern;
depositing a second conductive film atop said masking layer and in said third aperture pattern;
said deposition resulting in gaps between said conductive film in said third aperture pattern and said third insulating film;
removing said second layer of photosensitive material, thereby leaving a second conductive pattern in said third aperture pattern;
forming on said third insulating film and said second conductive pattern a fourth insulating film by a chemical vapor deposition reaction;
said second insulating film having a thickness which is at least one-half that of the width of the largest of said gaps.

17 more elements

A method for forming multiple levels of conductive patterns atop a substrate comprising:

forming a first insulating film on said substrate;
forming a first masking layer of photosensitive material on said first insulating film, said masking layer having at least one aperture;
forming apertures in said first insulating film corresponding to said first-masking-layer apertures, thereby forming a first aperture pattern;
depositing a first conductive film atop said first masking layer and in said first aperture pattern, the surface of the conductive film in said first aperture pattern being substantially flush with the surface of said first insulating film;
said deposition resulting in gaps between said conductive film in said first aperture pattern and said first insulating film;
removing said first masking layer, thereby leaving a first conductive pattern in said first aperture pattern;
forming on said first insulating film and said first conductive pattern a second insulating film of known thickness by a chemical vapor deposition reaction;
said second insulating film having a thickness which is at least one-half that of the width of the largest of said gaps, whereby a substantially planar second insulating layer is formed;
forming a second masking layer of photosensitive material on said second insulating layer, said masking layer having at least one aperture over said first conductive pattern;
forming apertures in said second insulating film corresponding to said second masking-layer-apertures to expose at least a portion of said first conductive pattern, thereby forming a second aperture pattern;
depositing a second conductive film atop said second masking layer and in said second apertures pattern, the surface of said second conductive film in said apertures being substantially flush with the surface of said second insulating film;
said deposition resulting in gaps between said second conductive film in said second apertures and said second insulating film;
removing said second masking layer, thereby leaving a second conductive pattern in said second aperture pattern;
forming on said second insulating film and said second conductive pattern a third insulating film by a chemical vapor deposition reaction;
said third insulating film having a thickness which is at least one-half that of the width of the largest of said gaps, whereby a substantially planar third insulating film is formed.

12 more elements

Dependencies are inferred from the claim text.

Planar insulation of conductive patterns by chemical vapor deposition and sputtering

Life of this patent

Planar insulation of conductive patterns by chemical vapor deposition and sputtering

Life of this patent

Abstract

Claims28