US 7,144,806 B1Granted

ALD of tantalum using a hydride reducing agent

AssigneeNovellus Systems, Inc.

InventorsJames A. Fair, Jungwan Sung, Nerissa Taylor

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Abstract

An ALD method deposits conformal tantalum-containing material layers on small features of a substrate surface. The method includes the following principal operations: depositing a thin conformal and saturated layer of tantalum-containing precursor over some or all of the substrate surface; using an inert gas or hydrogen plasma to purge the halogen byproducts and unused reactants; reducing the precursor to convert it to a conformal layer of tantalum or tantalum-containing material; using another purge of inert gas or hydrogen plasma to remove the halogen byproducts and unused reactants; and repeating the deposition/reduction cycles until a desired tantalum-containing material layer is achieved. An optional step of treating each newly formed surface of tantalum containing material with a nitrogen-containing agent can be added to create varying amounts of tantalum nitride.

Claims20

Dependent claims

A method of forming a layer of tantalum-containing material on a substrate, the method comprising:

(a) depositing from gas phase a tantalum-containing precursor onto the substrate to form an adsorbed saturated layer of the tantalum-containing precursor on the substrate, wherein the tantalum-containing precursor is deposited by a self-limiting reaction to form the adsorbed saturated layer;
(b) contacting the tantalum-containing precursor of the saturated layer with a boron hydride or a silicon hydride to form a tantalum-containing adhesion layer;
and
(c) converting a portion of the tantalum-containing adhesion layer to a nitride diffusion barrier on the tantalum-containing adhesion layer to form a bilayer of a tantalum-containing adhesion layer and a nitride diffusion barrier,
where the tantalum-containing adhesion layer comprise one or more of tantalum metal, tantalum silicide and tantalum boride and wherein (a) and (b) comprise introducing the tantalum-containing precursor and the hydride alternately over the substrate.

2 more elements

Dependencies are inferred from the claim text.