System and method for mitigating oxide growth in a gate dielectric

Abstract

Oxide growth of a gate dielectric layer that occurs between processes used in the fabrication of a gate dielectric structure can be reduced. The reduction in oxide growth can be achieved by maintaining the gate dielectric layer in an ambient effective to mitigate oxide growth of the gate dielectric layer between at least two sequential process steps used in the fabrication the gate dielectric structure. Maintaining the gate dielectric layer in an ambient effective to mitigate oxide growth also improves the uniformity of nitrogen implanted in the gate dielectric.

Description

TECHNICAL FIELD [0001] The present invention relates to processes for the manufacture of semiconductor devices and, more particularly, to the formation of a gate dielectric with a gate electrode. BACKGROUND OF THE INVENTION [0002] In complementary metal oxide silicon (CMOS) technology, a need to enhance the speed and increase the density of CMOS integrated circuits (IC's) has resulted in the evolution of transistor scaling, accompanied by progressively thinner gate dielectric oxide. Reduction in the thickness of a gate dielectric provides increased drive current, with resultant increased speed. In addition, a thinner gate dielectric offers enhanced control of channel charge, thereby reducing short channel effects. The fabrication of thinner gate oxides, however, presents gate leakage current and reliability issues. In particular, physically thinner gate oxides exhibit gate leakage current increasing exponentially with reduction in thickness. [0003] The leakage current can be mitigat...

AI Technical Summary

Benefits of technology

"The present invention relates to a method of reducing oxide growth of a gate dielectric layer during the formation of a gate dielectric structure. This method improves the uniformity of N-incorporation and reduces the EOT (effective oxide thickness) of the gate dielectric. It involves maintaining the gate dielectric in an ambient effective to mitigate oxide growth between process steps, such as an inert atmosphere or an inert gas, and actively purging the ambient with the inert gas to minimize moisture and airborne molecular contaminants. The resulting gate dielectric has a higher nitrogen content and lower EOT compared to a gate dielectric formed without being maintained in an effective ambient. This method can be used to improve the quality and consistency of the gate dielectric structure across wafers and processes."

Problems solved by technology

This high transfer pressure, however, is offset by the need to raise and lower the pressure between each process performed in the fabrication of the gate dielectric structure.

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