Method and structure for threshold voltage control and drive current improvement for high-k metal gate transistors

Abstract

A method of forming a device includes providing a substrate, forming an interfacial layer on the substrate, depositing a high-k dielectric layer on the interfacial layer, depositing an oxygen scavenging layer on the high-k dielectric layer and performing an anneal. A high-k metal gate transistor includes a substrate, an interfacial layer on the substrate, a high-k dielectric layer on the interfacial layer and an oxygen scavenging layer on the high-k dielectric layer.

Description

technical field [0001] The present invention relates generally to integrated circuits, and more particularly to methods of fabricating high-permittivity (high-k) dielectric gate structures with interfacial nitridation to adjust threshold voltage and improve drive current. Background technique [0002] Integrated circuits often employ active devices known as transistors such as field effect transistors (FETs). A Metal Oxide Semiconductor Field Effect Transistor (MOSFET) includes a silicon-based substrate including a pair of impurity regions (ie, a source junction and a drain junction) separated by a channel region. Above the channel region, gate electrodes are separated by a dielectric. The junction may include a dopant of the opposite type to the dopant present in the channel region. MOSFETs that include n-type doped junctions are called NFETs. A MOSFET that includes a p-type doped junction is called a PFET. The gate electrode may serve as a mask for the channel region d...

AI Technical Summary

Problems solved by technology

However, the capping layer will significantly reduce the channel mobility, thereby reducing the drive current of the device in addition to additional process complexity and cost

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