Method for forming copper wiring

Patent metadata

Field	Value
Publication number	US-9101067-B2
Application number	US-201314136838-A
Country	US
Kind code	B2
Filing date	Dec 20, 2013
Priority date	Dec 20, 2012
Publication date	Aug 4, 2015
Grant date	Aug 4, 2015

Abstract

In a Cu wiring forming method for forming a Cu wiring by filling Cu in a recess which is formed in a substrate in a predetermined pattern, a barrier film formed of a TaAlN film is formed at least on the surface of the recess by thermal ALD or thermal CVD. Then a Cu film is formed to fill the recess with the Cu film. Further, the Cu wiring is formed in the recess by polishing the entire surface of the substrate by CMP.

First claim

What is claimed is:

1. A Cu wiring forming method for forming a Cu wiring by filling Cu in a recess formed in a substrate in a predetermined pattern, the Cu wiring forming method comprising:
forming a barrier film comprising a TaAlN film on a surface of the substrate, wherein the TaAlN film is formed by thermal atomic layer deposition (ALD);
forming a Cu film by filling the recess with the Cu film; and
forming the Cu wiring in the recess by removing the barrier film and the Cu film formed outside the recess while leaving the barrier film and the Cu film formed in the recess, wherein the removing is performed by chemical-mechanical polish,
wherein forming the barrier film comprises: forming a TaN unit film by a first thermal ALD process; and forming an AlN unit film by a second thermal ALD process.

2. The Cu wiring forming method of claim 1 , further comprising, between the forming the barrier film and the forming the Cu film, forming a Ru film on the barrier film.

3. The Cu wiring forming method of claim 2 , wherein the Ru film is formed by chemical vapor deposition.

4. The Cu wiring forming method of claim 1 , wherein after or during the forming the barrier film, a film deposited on the substrate is subjected to plasma processing and modified by ion impact applied thereto.

5. The Cu wiring forming method of claim 4 , wherein a plasma for the plasma processing is generated by applying a high frequency power to a mounting table of the substrate.

6. The Cu wiring forming method of claim 5 , wherein the plasma is an Ar plasma.

7. The Cu wiring forming method of claim 4 , wherein, between the forming the TaN unit film and the forming the AlN unit film, the film deposited on the substrate is subjected to the plasma processing.

8. The Cu wiring forming method of claim 1 , wherein the forming the TaN unit film comprises performing one or more times of a first cycle comprising supplying a Ta compound into a processing chamber and adsorbing the Ta compound onto the substrate, purging the processing chamber, converting the absorbed Ta compound to TaN by nitriding/reduction, and purging the processing chamber; and
wherein the forming the AlN unit film comprises performing one or more times of a second cycle comprising supplying an Al compound into the processing chamber and adsorbing the Al compound onto the substrate, purging the processing chamber, converting the adsorbed Al compound to AlN by nitriding/reduction, and purging the processing chamber, and
wherein a number of the first cycles performed and a number of the second cycles performed are determined based on a predetermined atomic composition ratio between Ta and Al in the barrier film, and wherein the forming the TaN unit film and the forming the AlN unit film are repeated multiple times.

9. The Cu wiring forming method of claim 8 , wherein the first cycle is performed 4 to 8 times in forming the TaN unit film, and the second cycle is performed once in forming the AlN unit film.

10. The Cu wiring forming method of claim 8 further comprising absorbing an Al source material onto the substrate before the forming the barrier film.

11. The Cu wiring forming method of claim 1 , wherein the TaAlN film has a thickness of 2 nm or less.

12. The Cu wiring forming method of claim 1 , wherein the Cu film is formed by physical vapor deposition.

13. The Cu wiring forming method of claim 12 , wherein the Cu film is formed by using an apparatus configured to produce a plasma in a processing chamber comprising the substrate, wherein the plasma sputters Cu atoms from a Cu target, wherein sputtered Cu atoms are ionized by the plasma, and wherein the ionized Cu are attracted onto the substrate by a bias power applied to a mounting table of the substrate.

14. A non-transitory computer-readable storage medium storing a program, wherein the program, when executed by a processing device, causes the processing device to perform a method of controlling a Cu wiring forming system to perform a Cu wiring forming method comprising
forming a barrier film comprising a TaAlN film on a surface of a substrate by thermal atomic layer deposition (ALD);
forming a Cu film by filling a recess formed in the substrate with the Cu film; and
forming the Cu wiring in the recess by removing the barrier film and the Cu film formed outside the recess while leave the barrier film and the Cu film formed in the recess, wherein the removing comprises chemical-mechanical polish,
wherein the forming the barrier film comprises: forming a TaN unit film by a first thermal ALD process; and forming an AlN unit film by a second thermal ALD process.

Assignees

• Tokyo Electron Ltd

Inventors

• Ishizaka Tadahiro
• Hasegawa Toshio

Classifications

• H10P14/432

  using selective deposition · CPC title

• H10P14/44

  Physical vapour deposition [PVD] · CPC title

• H10P14/43

  Chemical deposition, e.g. chemical vapour deposition [CVD] · CPC title

• H10W20/0523

  by irradiating with ultraviolet or particle radiation · CPC title

• H10W20/425

  Barrier, adhesion or liner layers · CPC title