Process for producing integrated circuits including reduction using gaseous organic compounds

• US 6,921,712 B2
• Filed: 05/15/2001
• Issued: 07/26/2005
• Est. Priority Date: 05/15/2000
• Status: Expired due to Term

• Current Assignee: ASM International NV
• Original Assignee: ASM International NV
• Inventors: Elers, Kai-Erik, Soininen, Pekka Juha
• Primary Examiner(s): Fourson, George
• Assistant Examiner(s): Pham, Thanh V.
• Application Number:
  US10/276,663
• Publication Number:
  US 20040038529A1
• Time in Patent Office: 1,533 Days
• Field of Search: 438/584, 438/597, 438/658, 438685-687
• US Class Current: 438/597
• CPC Class Codes: H01L 21/02068 during, before or after processing of conductive layers, e.g. polysilicon or amorphous silicon layers
• CPC Class Codes: H01L 21/28562 Selective deposition
• CPC Class Codes: H01L 21/3105 After-treatment
• CPC Class Codes: H01L 21/321 After treatment
• CPC Class Codes: H01L 21/76807 for dual damascene structures
• CPC Class Codes: H01L 21/76814 post-treatment or after-treatment, e.g. cleaning or removal of oxides on underlying conductors
• CPC Class Codes: H01L 21/76823 transforming an insulating layer into a conductive layer
• CPC Class Codes: H01L 21/76831 in via holes or trenches, e.g. non-conductive sidewall liners
• CPC Class Codes: H01L 21/76834 formation of thin insulating films on the sidewalls or on top of conductors H01L21/76831 takes precedence
• CPC Class Codes: H01L 21/76838 characterised by the formation and the after-treatment of the conductors etching for patterning the conductors H01L21/3213
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76861 Post-treatment or after-treatment not introducing additional chemical elements into the layer
• CPC Class Codes: H01L 21/76862 Bombardment with particles, e.g. treatment in noble gas plasmas; UV irradiation
• CPC Class Codes: H01L 21/76873 for electroplating
• CPC Class Codes: H01L 21/76883 Post-treatment or after-treatment of the conductive material
• CPC Class Codes: H01L 21/76886 Modifying permanently or temporarily the pattern or the conductivity of conductive members, e.g. formation of alloys, reduction of contact resistances
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/45147 Copper (Cu) as principal constituent
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00011 : Not relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/01005 : Boron [B]
• CPC Class Codes: H01L 2924/12044 : OLED

Abstract

This invention concerns a process for producing integrated circuits containing at least one layer of elemental metal which during the processing of the integrated circuit is at least partly in the form of metal oxide, and the use of an organic compound containing certain functional groups for the reduction of a metal oxide layer formed during the production of an integrated circuit. According to the present process the metal oxide layer is at least partly reduced to elemental metal with a reducing agent selected from organic compounds containing one or more of the following functional groups: alcohol (—OH), aldehyde (—CHO), and carboxylic acid (—COOH).

Claims

1. A process for producing an integrated circuit comprising at least partially reducing a metal oxide layer to an elemental metal with a gaseous organic compound selected from the group consisting of:

(a) organic compounds comprising at least one alcohol (—

OH) group and selected from the group consisting of primary alcohols, secondary alcohols, tertiary alcohols, polyhydroxy alcohols, cyclic alcohols, aromatic alcohols, halogenated alcohols and other derivatives of alcohols;

(b) organic compounds comprising at least one aldehyde (—

CHO) group and selected from the group consisting of;

(i) compounds having the general formula (V)

R³—

CHO 

 

(V)

 

wherein R³ is hydrogen or a linear or branched C₁-C₂₀ alkyl or alkenyl group,

(ii) compounds having the general formula (VI)

OHC—

R⁴—

CHO 

 

(VI)

 

wherein R⁴ is zero or a linear or branched C₁-C₂₀ saturated or unsaturated hydrocarbon,

(iii) halogenated aldehydes, and

(iv) other derivatives of aldehydes; and

(C) organic compounds comprising at least one carboxylic acid (—

COOH) group and selected from the group consisting of;

(i) compounds having the general formula (VII)

R⁵COOH 

 

(VII)

 

wherein R⁵ is hydrogen or a linear or branched C₁-C₂₀ alkyl or alkenyl group,

(ii) polycarboxylic acids,

(iii) halogenated carboxylic acids, and

(iv) other derivatives of carboxylic acids.

2. The process of claim 1 wherein the metal oxide layer is copper oxide.

3. The process of claim 1, wherein the elemental metal is selected from the group consisting of molybdenum (Mo), tungsten (W), rhenium (Re), iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), silver (Ag), gold (Au), zinc (Zn), cadmium (Cd), indium (In), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb) and bismuth (Bi).

4. The process of claim 1, wherein the metal oxide layer is formed by depositing metal oxide.

5. The process of claim 1, wherein the metal oxide layer is formed by the oxidation of a metal layer.

6. The process of claim 1, wherein the thickness of the metal oxide layer is 0.1 to 1000 nm.

7. The process of claim 6, wherein the thickness of the metal oxide layer is 0.1 to 400 nm.

8. The process of claim 1, wherein the reduction is carried out at a temperature of 400°

C. or less.

9. The process of claim 1, wherein the reduced metal oxide is a seed layer for an electrochemically deposited metal layer.

10. The process of claim 1, wherein the metal oxide is at least partially reduced to elemental metal during a pre-chemical mechanical planarization (CMP) annealing.

11. The process of claim 1 wherein the metal oxide layer is at least partly reduced to elemental metal after the process step of the post-CMP cleaning.

12. The process of claim 1, wherein the metal oxide is at least partly reduced to elemental metal before the deposition of a diffusion barrier.

13. The process of claim 1, wherein the reduced metal oxide is a capacitor electrode.

14. The process of claim 1, wherein the reduced metal oxide is a transistor gate metal.

15. The process of claim 1, wherein the reduced metal oxide is an intermediate layer between silicon and tungsten plugs on the source and drain areas of a transistor.

16. The process of claim 1, wherein the reduced metal oxide is on a wire bonding pad.

17. The process of claim 1, wherein the metal oxide is formed during or after a resist stripping step in the manufacture of an integrated circuit device.

18. The process of claim 1, wherein the organic compound is a reducing agent comprising at least one alcohol (—

OH) group, said reducing agent being selected from the group consisting of primary alcohols, secondary alcohols, tertiary alcohols, polyhydroxy alcohols, cyclic alcohols, aromatic alcohols, halogenated alcohols and other derivatives of alcohols.

19. The process of claim 18, wherein the organic compound comprises a primary alcohol having the general formula (I)

R¹—

OH 

 

(I)

wherein R¹ is a linear or branched C₁-C₂₀ alkyl or alkenyl group.

21. The process of claim 18, wherein the organic compound comprises a secondary alcohol having the general formula (II)

wherein each R¹ is selected from the group consisting of linear or branched C₁-C₂₀ alkyl and alkenyl groups.

22. The process of claim 21, wherein each R¹ is selected from the group consisting of methyl, ethyl, propyl, butyl, pentyl and hexyl.

23. The process of claim 18, wherein the organic compound comprises a tertiary alcohol having the general formula (III)

wherein each R¹ is selected independently from the group consisting of linear or branched C₁-C₂₀ alkyl and alkenyl groups.

24. The process of claim 23, wherein each R¹ is selected from the group consisting of methyl, ethyl, propyl, butyl, pentyl and hexyl.

25. The process of claim 18, wherein the organic compound comprises a cyclic alcohol having an —

OH group attached to at least one carbon atom which is part of a ring of 1-10 atoms.

26. The process of claim 18, wherein the organic compound comprises an aromatic alcohol having at least one —

OH group attached either to the benzene ring or to a carbon atom in a side-chain attached to benzene ring.

27. The process of claim 1, wherein the organic compound is a reducing agent comprising at least one aldehyde (—

CHO) group, said reducing agent being selected from the group consisting of;

compounds having the general formula (V)

R³—

CHO 

 

(V)

 

wherein R³ is hydrogen or a linear or branched C₁-C₂₀ alkyl or alkenyl group;

compounds having the general formula (VI)

OHC—

R⁴—

CHO 

 

(VI)

 

wherein R⁴ is zero or a linear or branched C₁-C₂₀ saturated or unsaturated hydrocarbon;

halogenated aldehydes; and

other derivatives of aldehydes.

28. The process of claim 27 wherein R³ is selected from the group consisting of methyl, ethyl, propyl, butyl, pentyl and hexyl.

29. The process of claim 1, wherein the organic compound is a reducing agent comprising at least one carboxylic acid (—

COOH) group, said reducing agent being selected from the group consisting of;

compounds having the general formula (VII)

R⁵COOH 

 

(VII)

 

wherein R⁵ is hydrogen or a linear or branched C₁-C₂₀ alkyl or alkenyl group;

polycarboxylic acids;

halogenated carboxylic acids; and

other derivatives of carboxylic acids.

30. The process of claim 29, wherein R⁵ is selected from the group consisting of methyl, ethyl, propyl, butyl, pentyl and hexyl.

20. The process of claim 38, wherein R¹ is selected from the group consisting of methyl, ethyl, propyl, butyl, pentyl and hexyl.