Stratified gate dielectric stack for gate dielectric leakage reduction

Abstract

A stratified gate dielectric stack includes a first high dielectric constant (high-k) gate dielectric comprising a first high-k dielectric material, a band-gap-disrupting dielectric comprising a dielectric material having a different band gap than the first high-k dielectric material, and a second high-k gate dielectric comprising a second high-k dielectric material. The band-gap-disrupting dielectric includes at least one contiguous atomic layer of the dielectric material. Thus, the stratified gate dielectric stack includes a first atomic interface between the first high-k gate dielectric and the band-gap-disrupting dielectric, and a second atomic interface between the second high-k gate dielectric and the band-gap-disrupting dielectric that is spaced from the first atomic interface by at least one continuous atomic layer of the dielectric material of the band-gap-disrupting dielectric. The insertion of the band-gap disrupting dielectric results in lower gate leakage without resulting in any substantial changes in the threshold voltage characteristics and effective oxide thickness.

Description

CROSS REFERENCE TO RELATED APPLICATION[0001]This application is a continuation of U.S. patent application Ser. No. 13 / 449,647, filed Apr. 18, 2012 the entire content and disclosure of which is incorporated herein by reference.BACKGROUND[0002]The present disclosure generally relates to semiconductor devices, and particularly to a semiconductor structure having a gate dielectric comprising a stratified gate dielectric stack comprising two atomic interfaces that provide discontinuities in the band gap structure of the gate dielectric, and methods of manufacturing the same.[0003]One of the main challenges in advanced high-performance field effect transistors is the high gate leakage current through a high-k gate dielectric between the gate electrode and the body of a field effect transistor. The high-k gate dielectric consisting of a single homogeneous dielectric material requires to be continually reduced in thickness to obtain higher performance of the field effect transistor but at t...

AI Technical Summary

Benefits of technology

The patent describes a way to reduce gate leakage in semiconductor devices without affecting their effectiveness. This is achieved by using a layer of dielectric material that disrupts the structure of the gate dielectric. This results in a more robust and reliable semiconductor device. The use of a strated gate dielectric stack, which includes a first high-k gate dielectric, a band-gap-disrupting dielectric and a second high-k gate dielectric, can further enhance the device's performance.

Problems solved by technology

One of the main challenges in advanced high-performance field effect transistors is the high gate leakage current through a high-k gate dielectric between the gate electrode and the body of a field effect transistor.

The high-k gate dielectric consisting of a single homogeneous dielectric material requires to be continually reduced in thickness to obtain higher performance of the field effect transistor but at the expense of increased gate leakage.

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