Silane or borane treatment of metal thin films

Abstract

The negative effect of oxygen on some metal films can be reduced or prevented by contacting the films with a treatment agent comprising silane or borane. In some embodiments, one or more films in an NMOS gate stack are contacted with a treatment agent comprising silane or borane during or after deposition.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present application relates generally to processes for providing a protective treatment to metal thin films. In some embodiments, thin films used in metal gate and metal electrode applications in metal oxide semiconductor field effect transistors (MOSFETs), such as n-channel MOSFETs (NMOS) are treated either during or after deposition in order to prevent or reduce the effects of oxidation.[0003]2. Description of the Related Art[0004]Oxidation of a metal thin film can easily occur during many steps in processing, such as by exposure to atmospheric water or oxygen. In a multi-step fabrication process oxidation may occur between the deposition of each thin film, such as when transferring a wafer or substrate between deposition modules. Oxidation poses a problem in that it can affect the workfunction of a given thin film or an entire stack. And oxidation in one thin film may lead to oxidation of the interface between th...

AI Technical Summary

Benefits of technology

[0014]In some methods, the etch stop layer is a titanium nitride layer and the metal-containing layer comprises an n-type metal. The metal-containing layer in some methods comprises TiAl, TaC, HfC, TaAlC, TiAlSiC, TiAl B, TaAlB, TiAlSiB, TaAl, TiAlSiC TaAlSiB, or HfAlSiB. Some methods also include contacting the metal-containing layer with a silane or borane compound. The metal-containing layer in some methods is deposited by an atomic layer deposition process comprising multiple deposition cycles, and the substrate is contacted with a silane or borane compound during at least one of the deposition cycles. In some embodiments, the silane or borane is selected from the group consisting of monosilane, disilane, trisilane, borane, diborane, and triborane. And contacting the etch stop layer with a silane or borane compound in some methods does not increase the thickness first metal nitride layer.

Problems solved by technology

Oxidation of a metal thin film can easily occur during many steps in processing, such as by exposure to atmospheric water or oxygen.

Oxidation poses a problem in that it can affect the workfunction of a given thin film or an entire stack.

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