US 6,207,553 B1Granted

Method of forming multiple levels of patterned metallization

AssigneeAdvanced Micro Devices, Inc.

InventorsMatthew S. Buynoski, Ming-Ren Lin

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Abstract

Submicron-dimensioned metallization patterns are formed on a substrate surface by a photo-activated selective, anisotropic etching process, wherein selective portions of a metal layer are exposed to collimated UV passing through a pattern of submicron-sized openings in an overlying exposure mask. At least one photo-activatable etching material contained in a gas flowed through the space between the substrate surface and the mask selectively and anisotropically etches the exposed portions of the metal layer in thereby avoiding numerous masking and etching steps as in conventional photolithographic methodology. The inventive method is of particular utility in performing multi-level, in-laid, “back-end” metallization processing of high-density integrated circuit semiconductor devices.

A method of manufacturing a semiconductor device, which method comprises the sequential steps of:

(a) providing a substrate comprising a semiconductor wafer with a surface having a dielectric layer fonned thereover, said dielectric layer comprising a surface including a first in-laid metallization pattern including a plurality of spaced-apait metal features forming electrical contacts, vias, interlevel metallization, and/or interconnect routing of at least one active device region or component of said semiconductor wafer substrate;
(b) forming a layer of a preselected metal to a predetermined thickness over said surface of said dielectric layer and in ohmic contact with each of said plurality of spaced-apart metal features of said first in-laid metallization pattern said metal layer including a surface;
(c) positioning a patterned exposure mask at a predetermined spacing from said surface of said metal layer, said mask comprising a predetermined pattern of openings formed therethrough, said mask openings being positioned in a predetermined registered relation with the features of said first in-laid metallization pattern;
(d) establishing a gas atmosphere in the space between said surface of said metal layer and said patterned exposure mask, said gas atmosphere comprising at least one etchant material for photo-activated anisotropic etching of said metal layer;
(e) irradiating the portions of said gas atmosphere exposed through said pattern of mask openings with radiation of predetermined wavelength(s) for effecting photo-activated, selective, anisotropic etching of the portions of said metal layer exposed through said pattern of mask openings;
and
(f) continuing said photo-activated selective anisotropic etching of step (e) for an interval sufficient to remove the entire thickness of said metal layer at said exposed portions, thereby forming a patterned metal layer having predetermined portions in overlying, ohmic contact with selected features of said first in-laid metallization pattern.

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Abstract

Claims19