US 8,012,442 B2Granted

Method of forming mixed rare earth nitride and aluminum nitride films by atomic layer deposition

AssigneeTokyo Electron Limited

InventorRobert D. Clark

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Abstract

A method is provided for depositing a gate dielectric that includes at least two rare earth metal elements in the form of a nitride or an aluminum nitride. The method includes disposing a substrate in a process chamber and exposing the substrate to a gas pulse containing a first rare earth precursor and to a gas pulse containing a second rare earth precursor. The substrate may also optionally be exposed to a gas pulse containing an aluminum precursor. Sequentially after each precursor gas pulse, the substrate is exposed to a gas pulse of a nitrogen-containing gas. In alternative embodiments, the first and second rare earth precursors may be pulsed together, and either or both may be pulsed together with the aluminum precursor. The first and second rare earth precursors comprise a different rare earth metal element. The sequential exposing steps may be repeated to deposit a mixed rare earth nitride or aluminum nitride layer with a desired thickness. Purge or evacuation steps may also be performed after each gas pulse.

Claims25

Dependent claims

A method for forming a mixed rare earth nitride or a mixed rare earth aluminum nitride film, comprising:

disposing a substrate in a process chamber;
and
exposing the substrate to a gas pulse sequence to deposit a mixed rare earth nitride film or a mixed rare earth aluminum nitride film with a desired thickness, wherein the gas pulse sequence includes, in any order:
a) sequentially first, exposing the substrate to a gas pulse comprising a first rare earth precursor, and second, exposing the substrate to a gas pulse comprising a nitrogen-containing gas;
b) sequentially first, exposing the substrate to a gas pulse comprising a second rare earth precursor, and second, exposing the substrate to a gas pulse comprising the nitrogen-containing gas, wherein the first and second rare earth precursors contain different rare earth metal elements of differing and mismatched atomic sizes;
and
c) optionally, sequentially first, exposing the substrate to a gas pulse containing an aluminum precursor and second, exposing the substrate to a gas pulse containing the nitrogen-containing gas,
wherein each of a), b) and optionally c) are optionally repeated any number of desired times, wherein the gas pulse sequence including a), b) and optionally c) is optionally repeated, in any order, any number of desired times to achieve the desired thickness, and wherein the different rare earth metal elements are in solid solution in the mixed rare earth nitride or the mixed rare earth aluminum nitride film and wherein the mixed rare earth nitride or the mixed rare earth aluminum nitride film has a dielectric constant that is greater than the dielectric constant of a nitride or an aluminum nitride film having only one of the different rare earth metal elements present in the mixed rare earth nitride or the mixed rare earth aluminum nitride film.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/278,393Filed 31 Mar 2006
Published: US 2007/0237698 A111 Oct 2007
Granted: 6 Sep 2011
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

C23C 16/34
Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides: nitrides
C23C 16/45525
Pulsed gas flow or change of composition over time: atomic layer deposition [ALD]
C23C 16/45531
Characterized by the ALD cycle, e.g. different flows or temperatures during half-reactions, unusual pulsing sequence, use of precursor mixtures…
H10P 14/6336
Using decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition: in the presence of a plasma [PECVD]