Selective deposition of metal-containing cap layers for semiconductor devices

• US 8,242,019 B2
• Filed: 03/31/2009
• Issued: 08/14/2012
• Est. Priority Date: 03/31/2009
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Mizuno, Shigeru, Hoshino, Satohiko, Nagai, Hiroyuki, Chiba, Yuki, Cerio, Frank M. Jr., Ishizaka, Tadahiro
• Primary Examiner(s): Ha, Nathan
• Assistant Examiner(s): Jung, Michael
• Application Number:
  US12/414,917
• Publication Number:
  US 20100248473A1
• Time in Patent Office: 1,232 Days
• Field of Search: None
• US Class Current: 438/686
• CPC Class Codes: H01L 21/02063 the processing being the formation of vias or contact holes
• CPC Class Codes: H01L 21/02074 the processing being a planarization of conductive layers
• CPC Class Codes: H01L 21/3105 After-treatment
• 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 21/76826 by contacting the layer with gases, liquids or plasmas
• CPC Class Codes: H01L 21/76828 thermal treatment
• CPC Class Codes: H01L 21/76846 Layer combinations
• CPC Class Codes: H01L 21/76849 the layer being positioned on top of the main fill metal
• CPC Class Codes: H01L 21/76856 by treatment in plasmas or gaseous environments, e.g. nitriding a refractory metal liner
• CPC Class Codes: H01L 21/76859 by ion implantation
• CPC Class Codes: H01L 21/76883 Post-treatment or after-treatment of the conductive material

Abstract

A method for integrating metal-containing cap layers into copper (Cu) metallization of semiconductor devices. In one embodiment, the method includes providing a patterned substrate containing metal surfaces and dielectric layer surfaces, and modifying the dielectric layer surfaces by exposure to a reactant gas containing a hydrophobic functional group, where the modifying substitutes a hydrophilic functional group in the dielectric layer surfaces with a hydrophobic functional group. The method further includes depositing metal-containing cap layers selectively on the metal surfaces by exposing the modified dielectric layer surfaces and the metal surfaces to a deposition gas containing metal-containing precursor vapor.

Claims

1. A method of forming a semiconductor device, comprising:

providing a patterned substrate containing metal surfaces and dielectric layer surfaces;

modifying the dielectric layer surfaces by exposure to a reactant gas containing a hydrophobic functional group, the modifying substituting a hydrophilic functional group in the dielectric layer surfaces with the hydrophobic functional group; and

depositing metal-containing cap layers selectively on the metal surfaces by exposing the modified dielectric layer surfaces and the metal surfaces to a deposition gas containing metal-containing precursor vapor, wherein the depositing comprises;

exposing the modified dielectric layer surfaces and the metal surfaces to the metal-containing precursor vapor to deposit metal layers selectively on the metal surfaces, wherein the metal-containing precursor vapor contains a metal element selected from platinum (Pt), gold (Au), ruthenium (Ru), cobalt (Co), tungsten (W), rhodium (Rh), iridium (Ir), or palladium (Pd), or a combination of two or more thereof, and

incorporating a dopant into the metal layers by exposing the deposited metal layers to a dopant gas selected from PH₃, BH₃, B₂H₆, BF₃, NF₃, NH₃, N₂, N₂H₄, PF₃, PBr₃, BCl₃, Bl₃, SiH₄, Si₂H₆, SiH₃Cl, SiH₂Cl₂, SiHCl₃, SiCl₄, Si₂Cl₆, SiH₃F, SiH₂F, SiHF₃, SiF₄, Si₂F₆, GeH₄, or GeCl₄, or a combination of two or more thereof, wherein the incorporating comprises exposing the metal layers to a gas cluster ion beam (GCIB) or an ion implant beam containing the dopant gas.

2. The method of claim 1, wherein the reactant gas comprises a silicon-containing gas selected from an alkyl silane, an alkoxysilane, an alkyl alkoxysilane, an alkyl siloxane, an alkoxysiloxane, an alkyl alkoxysiloxane, an aryl silane, an acyl silane, an aryl siloxane, an acyl siloxane, a silazane, or any combination thereof.

3. The method of claim 1, wherein the modifying further comprises:

adsorbing the reactant gas on the metal surfaces; and

heat-treating the patterned substrate at a temperature that selectively removes the adsorbed reactant gas from the metal surfaces without removing the hydrophobic functional groups from the modified dielectric layer surfaces.

4. The method of claim 1, further comprising:

exposing the metal surfaces to a reducing gas to reduce oxidized metal on the metal surfaces.

5. The method of claim 1, further comprising:

following the exposing of the modified dielectric layer surfaces and the metal surfaces to the metal-containing precursor vapor and prior to the incorporating, removing the hydrophobic functional group from the modified dielectric layer surfaces.

6. The method of claim 1, wherein the providing comprises:

providing a patterned substrate containing a dielectric layer having the dielectric layer surfaces, the patterned substrate further containing metal surfaces inside recessed features in the dielectric layer.

7. The method of claim 1, wherein the metal surfaces are located on planarized metal layers filling recessed features in a dielectric layer.

8. A method of forming a semiconductor device, comprising:

providing a patterned substrate containing metal surfaces and dielectric layer surfaces;

modifying the dielectric layer surfaces by exposure to a reactant gas containing a hydrophobic functional group, the modifying substituting a hydrophilic functional group in the dielectric layer surfaces with the hydrophobic functional group; and

depositing metal-containing cap layers selectively on the metal surfaces by exposing the modified dielectric layer surfaces and the metal surfaces to a deposition gas containing metal-containing precursor vapor and a non-metal dopant gas, wherein the modified dielectric layer surfaces and the metal surfaces are contemporaneously exposed to the metal-containing precursor vapor and the non-metal dopant gas, and wherein the metal-containing precursor vapor contains a metal element selected from platinum (Pt), gold (Au), ruthenium (Ru), cobalt (Co), tungsten (W), rhodium (Rh), iridium (Ir), or palladium (Pd), or a combination of two or more thereof, and the dopant gas is selected from PH₃, BH₃, B₂H₆, BF₃, NF₃, NH₃, N₂, N₂H₄, PF₃, PBr₃, BCl₃, Bl₃, SiH₄, Si₂H₆, SiH₃Cl, SiH₂Cl₂, SiHCl₃, SiCl₄, Si₂Cl₆, SiH₃F, SiH₂F, SiHF₃, SiF₄, Si₂F₆, GeH₄, or GeCl₄, or a combination of two or more thereof.

9. The method of claim 8, wherein the metal-containing cap layers contain metal compound layers having the metal element and a non-metal dopant element selected from phosphorus (P), boron (B), nitrogen (N), fluorine (F), bromine (Br), silicon (Si), or germanium (Ge), or a combination of two or more thereof.