Advanced Micro Devices Corporation

Spansion Llc.

John C Foster

Paul L King

Paul Raymond Besser

Matthew S Buynoski

Eric N Paton

Qi Xiang

Minh Van Ngo

Christy Mei-Chu Woo

George Jonathan Kluth

Jacques J Bertrand

Ercan Adem

Scott Allan Bell

Simon S Chan

Allison Holbrook

Phillip Lawrence Jones

A high K layer, such as aluminum oxide or hafnium oxide, may be formed with a deposition process that uses an ion implantation to damage portions of the high K material that are to be later etched. More particularly, in one implementation, a semiconductor device is manufactured by forming a first dielectric over a substrate, forming a charge storage element over the first dielectric, forming a second dielectric above the charge storage element, implantation ions into select portions of the second dielectric, and etching the ion implanted select portions of the second dielectric.

Enhanced etching of a high dielectric constant layer

A method for preventing the thermal decomposition of a high-K dielectric layer of a gate electrode during the formation of a metal silicide on the gate electrode by using nickel as the metal component of the silicide.

Silicide process using high K-dielectrics

The formation of metal silicides in silicon nitride spacers on a gate electrode causes bridging between a gate electrode and the source and drain regions of a semiconductor device. The bridging is prevented by forming a thin layer of silicon oxide on the silicon nitride spacers prior to forming the metal silicide layers on the device.

Passivation of nitride spacer

A self-aligned silicide process that can accommodate a low thermal budget and form silicide regions of small dimensions in a controlled reaction. In a first temperature treatment, nickel metal or nickel alloy is reacted with a silicon material to form at least one high resistance nickel silicide region. Unreacted nickel is removed. A dielectric layer is then deposited over a high resistance nickel silicide regions. In a second temperature treatment, the at least one high resistance nickel silicide region and dielectric layer are reacted at a prescribed temperature to form at least one low resistance silicide region and process the dielectric layer. Bridging between regions is avoided by the two-step process as silicide growth is controlled, and unreacted nickel between silicide regions is removed after the first temperature treatment. The processing of the high resistance nickel silicide regions and the dielectric layer are conveniently combined into a single temperature treatment.

Method of forming nickel silicide using a one-step rapid thermal anneal process and backend processing

A method for implementing a self-aligned metal silicide gate is achieved by confining a metal within a recess overlying a channel and annealing to cause metal and its overlying silicon to interact to form the self-aligned metal silicide gate. A gate dielectric layer formed of oxynitride or a nitride/oxide stack is formed on the bottom and sidewalls of the recess prior to depositing the silicon. The metal is removed except for the portion of the metal in the recess. A planarization step is performed to remove the remaining unreacted silicon by chemical mechanical polishing until no silicon is detected.

Metal silicide gate transistors

A method of forming a fully silicidized gate of a semiconductor device includes forming silicide in active regions and a portion of a gate. A shield layer is blanket deposited over the device. The top surface of the gate electrode is then exposed. A refractory metal layer is deposited and annealing is performed to cause the metal to react with the gate and fully silicidize the gate, with the shield layer protecting the active regions of the device from further silicidization to thereby prevent spiking and current leakage in the active regions.

Process for forming fully silicided gates

A method for implementing a self-aligned low temperature metal silicide gate is achieved by confining amorphous silicon within a recess overlying a channel and annealing to cause the amorphous silicon with its overlying low temperature silicidation metal to interact to form the self-aligned low temperature metal silicide gate. A precursor having a temporary gate is used to form the self-aligned low temperature silicide gate. The remaining portions of the low temperature silicidation metal is removed by manipulating the etch selectivity between the low temperature silicidation metal and the self-aligned low temperature metal silicide gate.

Damascene NiSi metal gate high-k transistor

A semiconductor structure and method for making the same provides a gate dielectric formed of oxynitride or a nitride/oxide stack formed within a recess. Amorphous silicon is deposited on the gate dielectric within the recess and a metal is deposited on the amorphous silicon. An annealing process forms a metal silicide gate within the recess on the gate dielectric. A wider range of metal materials can be selected because the gate dielectric formed of oxynitride or a nitride/oxide stack remains stable during the silicidation process. The metal silicide gate significantly reduces the sheet resistance between the gate and gate terminal.

Silicide gate transistors

A damascene gate semiconductor structure that is formed utilizing a silicide stop layer. Initially, a gate opening is provided in an insulating layer on a substrate. A first dielectric layer is deposited in the gate opening over the substrate. A silicide stop layer is then deposited in the gate opening over the first silicon layer. A second silicon layer is then deposited in the gate opening over the silicide stop layer. A metal or alloy layer is then deposited over the insulating and the second silicon layer. The damascene semiconductor structure is then temperature treated to react the metal or alloy layer with the second silicon layer to form a silicide layer. Any unreated metal or alloy is then removed from the metal or alloy layer.

Method of making silicide stop layer in a damascene semiconductor structure

Shorting between a transistor gate electrode and associated source/drain regions due to metal silicide formation on the sidewall spacers is prevented by passivating the sidewall spacer surfaces with a mixture of ozone and water. Embodiments of the invention include spraying the wafer with or immersing the wafer in, a saturated solution of ozone in water.

Passivation of sidewall spacers using ozonated water

Bridging between nickel silicide layers on a gate electrode and associated source/drain regions along silicon nitride sidewall spacers is prevented by hydrogen passivation of the exposed surfaces of the silicon nitride sidewall spacers. Embodiments include treating the silicon nitride sidewall spacers with a solution of HF and H O, at a HF:H O volume ratio of about 100:1 to about 200:1 for up to about 60 seconds at room temperature. Hydrogen passivation reduces the number of silicon dangling bonds, thereby avoiding reaction with subsequently deposited nickel and, hence, avoiding the formation of a bridging film of nickel silicide on the sidewall spacers.

Hydrogen passivated silicon nitride spacers for reduced nickel silicide bridging

Shorting between a transistor gate electrode and associated source/drain regions due to metal silicide formation on the sidewall spacers is prevented by passivating the sidewall spacer surfaces with a solution of iodine and ethanol. Embodiments of the invention include spraying the wafer with or immersing the wafer in, a solution of iodine in ethanol.

Passivation of semiconductor device surfaces using an iodine/ethanol solution

A method for implementing a self-aligned metal silicide gate is achieved by confining amorphous silicon within a recess overlying a channel and annealing to cause the amorphous silicon with its overlying metal to interact to form the self-aligned metal silicide gate. A gate dielectric layer formed of oxynitride or a nitride/oxide stack is formed on the bottom and sidewalls of the recess prior to depositing the silicon. The silicon is removed except for the portion of the silicon in the recess. The remaining portions of the metal are removed by manipulating the etch selectivity between the metal and the self-aligned metal silicide gate.

A method for implementing a self-aligned low temperature metal silicide gate is achieved by confining a low temperature silicidation metal within a recess overlying a channel and annealing to cause the low temperature silicidation metal and its overlying silicon to interact to form the self-aligned low temperature metal silicide gate. A planarization step is performed to remove the remaining unreacted silicon by chemical mechanical polishing until no silicon is detected.

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Mountain View, CA, United States of America

John C Foster