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US 5,688,717 AGranted
Construction that prevents the undercut of interconnect lines in plasma metal etch systems
AssigneeAdvanced Micro Devices, Inc.
InventorsLewis Shen, Sheshadri Ramaswami, Mark Chang, Robin Cheung
Life of this patent
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Abstract
A Ti.sub.x N.sub.y layer, not necessarily stoichiometric, is interposed between a titanium or aluminum interconnect layer to improve adhesion and prevent re-entrant undercutting and lifting of the interconnect layer during the process of patterning and plasma etching to form interconnect lines on a substrate, such as an oxide.
Claims15
An improvement in a process for reducing re-entrant undercutting of aluminum on titanium interconnect conducting lines formed over a semiconductor substrate, said process comprising:
- forming an inter-metal layer dielectric consisting essentially of an oxide;
- and
- forming a patterned multi-layer structure on said inter-metal layer dielectric, said patterned multi-layer structure comprising a titanium nitride anti-reflection layer formed on an aluminum layer formed on a titanium layer formed on said oxide layer, the improvement consisting essentially of:
- (a) depositing in either order on said oxide to form said inter-metal layer dielectric (1) a layer consisting essentially of nitrogen and titanium and (2) said titanium layer, thereby forming a titanium-containing layer;
- (b) depositing said aluminum layer on said titanium-containing layer;
- (c) depositing said titanium nitride anti-reflection layer on said aluminum layer;
- and
- (d) patterning and etching all metal-containing layers to form said interconnect conducting lines.
5 more elements
Dependencies are inferred from the claim text.