Method for depositing nanolaminate thin films on sensitive surfaces

• US 20060079090A1
• Filed: 11/28/2005
• Published: 04/13/2006
• Est. Priority Date: 10/15/1999
• Status: Active Grant

• Current Assignee: Kai-Erik Elers, Pekka Juha Soininen, Saanila Ville Antero, Sari Johanna Kaipio, Suvi P. Haukka
• Original Assignee: Kai-Erik Elers, Pekka Juha Soininen, Saanila Ville Antero, Sari Johanna Kaipio, Suvi P. Haukka
• Inventors: Elers, Kai-Erik, Haukka, Suvi P., Soininen, Pekka Juha, Saanila, Ville Antero, Kaipio, Sari Johanna
• Granted Patent: US 7,749,871 B2
• Time in Patent Office: Days
• US Class Current: 438/685
• CPC Class Codes: C23C 16/32 Carbides
• CPC Class Codes: C23C 16/34 Nitrides C23C16/303 takes precedence
• CPC Class Codes: C23C 16/44 characterised by the method of coating C23C16/04 takes precedence
• CPC Class Codes: C23C 16/4401 Means for minimising impurities, e.g. dust, moisture or residual gas, in the reaction chamber
• CPC Class Codes: C23C 16/45525 Atomic layer deposition [ALD]
• CPC Class Codes: C23C 16/45529 specially adapted for making a layer stack of alternating different compositions or gradient compositions
• CPC Class Codes: C23C 16/45534 Use of auxiliary reactants other than used for contributing to the composition of the main film, e.g. catalysts, activators or scavengers
• CPC Class Codes: C30B 25/02 Epitaxial-layer growth
• CPC Class Codes: C30B 29/02 Elements
• CPC Class Codes: C30B 29/36 Carbides
• CPC Class Codes: C30B 29/38 Nitrides
• CPC Class Codes: H01L 21/28562 Selective deposition
• CPC Class Codes: H01L 21/28568 the conductive layers comprising transition metals H01L21/28518 takes precedence
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76846 Layer combinations
• CPC Class Codes: H01L 21/76877 Filling of holes, grooves or trenches, e.g. vias, with conductive material

Abstract

The present method provides tools for growing conformal metal nitride, metal carbide and metal thin films, and nanolaminate structures incorporating these films, from aggressive chemicals. The amount of corrosive chemical compounds, such as hydrogen halides, is reduced during the deposition of transition metal, transition metal carbide and transition metal nitride thin films on various surfaces, such as metals and oxides. Getter compounds protect surfaces sensitive to hydrogen halides and ammonium halides, such as aluminum, copper, silicon oxide and the layers being deposited, against corrosion. Nanolaminate structures (20) incorporating metal nitrides, such as titanium nitride (30) and tungsten nitride (40), and metal carbides, and methods for forming the same, are also disclosed.

Claims

1. An atomic layer deposition (ALD) process for growing a carbon-containing metallic film on a substrate in a reaction space comprising the sequential steps of:

a) feeding a vapor-phase pulse of a metal source chemical into the reaction space with an inert carrier gas;

b) purging the reaction space with an inert gas;

c) feeding a vapor-phase pulse of a gettering compound into the reaction space;

d) purging the reaction space with an inert gas; and

e) repeating steps a) through d) until the carbon-containing metal film of a desired thickness is formed;

wherein the gettering compound comprises carbon and leaves carbon in the film.

2. The process of claim 1, wherein the metal in the metal source chemical is selected from the group consisting of W, Mo, Cr, Ta, Nb, V, Hf, Zr and Ti.

3. The process of claim 1, wherein the metal source chemical is selected from the group consisting of metal halides.

4. The process of claim 3, wherein the metal source chemical is selected from the group consisting of metal chlorides.

5. The process of claim 4, wherein the metal source chemical is selected from the group consisting of TaCl5, TiCl4 and NbCl5.

6. The process of claim 1, wherein the gettering compound is selected from the group consisting of alkyl aluminum, alkyl zinc, organo-lead, organo-iron, gallium and indium compounds that have at least one metal-carbon bond.

7. The process of claim 6, wherein the gettering compound is trimethylaluminum.

8. The process of claim 1, wherein the carbon-containing metallic film comprises metal carbide.

9. The process of claim 8, wherein the metal carbide is selected from the group consisting of tungsten carbide, tantalum carbide, niobium carbide and titanium carbide.

10. The process of claim 1, wherein the substrate comprises metal oxide or silicon oxide.

11. An atomic layer deposition (ALD) process for growing a metal nitride film on a substrate in a reaction space comprising the sequential steps of:

a) feeding a vapor-phase pulse of a metal source chemical into the reaction space with an inert carrier gas;

b) purging the reaction space with an inert gas;

c) feeding a vapor-phase pulse of a carbon compound into the reaction space;

d) purging the reaction space with an inert gas;

e) feeding a vapor-phase pulse of a nitrogen source chemical into the reaction space;

f) purging the reaction space with an inert gas; and

g) repeating steps a) through f) until a metal nitride film of a desired thickness is formed.

12. The process of claim 11, wherein the carbon compound is selected from the group consisting of carbon compound where there exists double or triple bonded carbon.

13. The process of claim 12, wherein the carbon compound is C₂H₂ or C₂H₄.

14. The process of claim 11, wherein the metal in the metal source chemical is selected from the group consisting of W, Mo, Cr, Ta, Nb, V, Hf, Zr and Ti.

15. The process of claim 11, wherein the metal source chemical is selected from the group consisting of metal halides.

16. The process of claim 15, wherein the metal source chemical is selected from the group consisting of metal chlorides.

17. The process of claim 11, wherein the nitrogen source chemical is selected from the group consisting of ammonia (NH3) and its salts, hydrogen azide (HN3) and the alkyl derivates thereof, hydrazine (N2H4) and salts of hydrazine, alkyl derivates of hydrazine, nitrogen fluoride NF3, hydroxylamine (NH2OH) and salts thereof, primary, secondary and tertiary amines, nitrogen radicals, and excited state nitrogen (N2*), wherein * is a free electron capable of bonding.

18. The process of claim 17, wherein the nitrogen source chemical is NH3.

19. The process of claim 11, wherein the substrate is selected from the group consisting of silicon, silicon oxide (SiO2), coated silicon, low-k materials, metals, copper, aluminum, metal alloys, metal oxides, transition metal nitrides, silicon nitride and a combination of two or more of said materials.