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US 4,400,257 AGranted
Method of forming metal lines
AssigneeRCA Corporation
InventorGordon C. Taylor
Life of this patent
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Abstract
A method of forming metal lines is described for semiconductor processing wherein a line mask is initially ion milled to provide a mask contour which promotes the onset of chemical etching at the base of the mask. This produces a metal line that has a tapered cross-sectional dimension wherein the base of the line is narrower than the top.
Claims7
A process for forming a conductive line on a substrate, comprising steps of:
- forming a conductive layer on the substrate;
- forming an apertured masking layer on the conductive layer, the aperture having a first dimension at the surface of the masking layer adjacent the conductive layer and a narrower dimension at its opposite surface;
- depositing a line masking layer on the exposed surface of the metal layer;
- removing the apertured masking layer;
- ion milling the line masking layer and the exposed portions of the conductive layer for a period of time sufficient to form trenches on either side of the line masking layer and to simultaneously redeposit a portion of the line masking material and the conductive layer on the sides of the line masking material to form projecting wings thereon;
- and
- chemically etching the exposed conductive layer and a portion of the conductive layer under the line masking layer.
4 more elements
Dependencies are inferred from the claim text.