Method of making self-aligned, lateral diffusion barrier in metal lines to eliminate electromigration
AssigneeInternational Business Machines Corporation
InventorsGlenn A. Biery, Daniel M. Boyne, Hormazdyar M. Dalal
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Abstract
A method of providing interconnections to a semiconductor integrated chip designed to eliminate electromigration. The method includes the steps of forming an interconnection with segments of Al interspersed with segments of a refractory metal, wherein each aluminum segments is followed by a segment of refractory metal, aligning the aluminum and refractory metal segments with respect to each other ensuring electrical continuity.
Claims12
A method of providing interconnections to a semiconductor integrated chip, wherein said interconnections are designed to minimize electromigration, said method comprising the steps of:
- forming islands of refractory metal on an insulated substrate at locations where an interconnection is to be made;
- inserting an aluminum island between every two adjoining said refractory metal islands, wherein
- said refractory metal islands alternating with said aluminum islands are serially connected to each other to ensure electrical continuity.
A method of providing interconnections to a semiconductor integrated chip designed to minimize electromigration, said method comprises the steps of:
- forming refractory metal islands on top of a substrate at locations where an interconnection is to be made;
- depositing a blanket layer of aluminum on top of said substrate covering all said refractory metal islands;
- polishing said aluminum blanket layer until said refractory metal islands are exposed;
- and
- forming interconnections, by alternately connecting said exposed aluminum and said refractory metal islands, using photomasking and reactive ion etching.
A method of providing interconnections to a semiconductor integrated chip designed to minimize electromigration, said method comprises the steps of:
- forming an array of holes in a layer of aluminum by photomasking and aluminum etching;
- depositing a layer of refractory metal on top of said layer of aluminum;
- polishing the layer of refractory metal to expose aluminum thereby obtaining said layer of aluminum imbedded with refractory metal islands;
- and
- photomasking and etching said layer of aluminum imbedded with refractory metal islands, wherein interconnections comprised of alternating aluminum and refractory metal sections are formed.
Dependencies are inferred from the claim text.