Lsi Logic Corporation

Lsi Corporation

Hao Cui

Wilbur G Catabay

Peter Austin Burke

Wei-Jen Hsia

Sey-Shing Sun

Vladimir Zubkov

William K Barth

Agajan Suvkhanov

Grace S Sun

Sethuraman Lakshminarayanan

Embodiments of the invention include a copper interconnect structure having increased electromigration lifetime. Such structures can include a semiconductor substrate having a copper layer formed thereon. A dielectric barrier stack is formed on the copper layer. The dielectric barrier stack includes a first portion formed adjacent to the copper layer and a second portion formed on the first portion, the first portion having improved adhesion to copper relative to the second portion and both portions are formed having resistance to copper diffusion. The invention also includes several embodiments for constructing such structures. Adhesion of the dielectric barrier stack to copper can be increased by plasma treating or ion implanting selected portions of the dielectric barrier stack with adhesion enhancing materials to increase the concentration of such materials in the stack.

Dielectric barrier layer for increasing electromigration lifetimes in copper interconnect structures

A method of forming a planarized layer on a substrate, where the substrate is cleaned, and the layer is formed having a surface with high portions and low portions. A resistive mask is formed over the low portions of the layer, but not over the high portions of the layer. The surface of the layer is etched, where the high portions of the layer are exposed to the etch, but the low portions of the layer underlying the resistive mask are not exposed to the etch. The etch of the surface of the layer is continued until the high portions of the layer are at substantially the same level as the low portions of the layer, thereby providing an initial planarization of the surface of the layer. The resistive mask is removed from the surface of the layer, and all of the surface of the layer is planarized to provide a planarized layer.

Planarization with reduced dishing

A method for forming damascene interconnect copper diffusion barrier layers includes implanting calcium into the sidewalls of the trenches and vias. The calcium implantation into dielectric layers, such as oxides, is used to prevent Cu diffusion into oxide, such as during an annealing process step. The improved barrier layers of the present invention help prevent delamination of the Cu from the dielectric.

Method for creating barrier layers for copper diffusion

A method for forming a substantially oxygen-free silicon carbide layer on a substrate, where the silicon carbide layer has a dielectric constant of less than about four. The substrate is held at a deposition temperature of between about zero centigrade and about one hundred centigrade, and a gas flow of tetramethylsilane is introduced at a rate of no more than about one thousand scientific cubic centimeters per minute. The deposition pressure is held between about one milli Torr and about one hundred Torr, and a radio frequency plasma discharge is produced with a power of no more than about two kilowatts. The plasma discharge is halted when a desired thickness of the silicon carbide layer has been formed.

Ultra low dielectric constant thin film

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Gresham, OR, United States of America

Hao Cui