Graded oxide/nitride via structure and method of fabrication therefor
AssigneeInternational Business Machines Corporation
InventorRajiv V. Joshi
Life of this patent
Estimating the term…
Abstract
A structure and method for fabricating the structure, which includes a layer containing a refractory metal and a substrate to which the refractory metal-containing layer does not strongly adhere, there being a thin bonding layer between the substrate and the refractory metal-containing layer for providing good adherence between the refractory metal-containing layer and the substrate. The bonding layer is an oxide, nitride or mixed oxy-nitride layer initially prepared to be Si-rich in a surface region thereof. Inclusions of the refractory metal are produced in the bonding layer by substituting the refractory metal for excess free silicon therein. These inclusions become nucleation and bonding sites for refractory metal deposition, ensuring good adhesion.
Claims27
A multilayer structure including, in combination,
- a substrate to which a layer containing a refractory metal is to be bonded, said substrate being one which does not bond strongly to said layer containing a refractory metal,
- a layer containing said refractory metal,
- an insulating bonding layer selected from the group consisting of silicon oxides, silicon nitrides, and silicon oxy-nitrides located between said layer containing said refractory metal and said bonding layer having free silicon particles therein and inclusions of said refractory metal substituted for at least some of said free silicon within at least the surface region of said bonding layer and forming bonding sites, the amount of said free silicon and said inclusions being sufficiently small that said bonding layer emains insulating, said layer containing said refractory metal being strongly bonded to said sites within said insulating bonding layer.
A multilayer structure including, in combination:
- a substrate to shich a tungsten-containing layer is to be bonded, said substrate being comprised of a material to which tungsten does not bond strongly,
- a tungsten-containing layer overlaying said substrate, and
- an insulating bonding layer selected from the group consisting of silicon oxides, silicon nitrides and silicon oxy-nitrides located between said tungsten-containing layer and said substrate, said bonding layer having at least in a tungsten-contacting surface region thereof free silicon particles and tungsten inclusions where said tungsten inclusions are tungsten particles substituted for at least some of said free silicon, said tungsten inclusions being bonding sites for tungsten atoms in said tungsten-containing layer the amount of said free silicon and said inclusions being sufficiently small that said bonding layer remains insulating.
A method for forming a structure wherein a layer containing a refractory metal is to be bonded to a substrate to which said layer does not strongly adhere, comprising the steps of
- depositing an insulating bonding layer selected from the group consisting of silicon oxides, silicon nitrides and silicon oxy-nitrides on said substrate, said bonding layer strongly adhering to said substrate and containing free silicon particles therein at least in a surface region of said bonding layer to be contacted by said layer containing said refractory metal,
- substituting atoms of said refractory metal for at least some of said free silicon in said bonding layer to produce refractory metal inclusions within the body of said bonding layer, the amount of said free silicon and said inclusions being sufficiently small that said bonding layer remains insulating, said inclusions being bonding sites for deposition of said layer containing said refractory metal, and
- depositing said layer containing said refractory metal onto said bonding layer, said bonding sites strongly adhering said deposited layer containing a refractory metal to said insulating bonding layer.
A method for bonding a tungsten-containing layer to a substrate to which said tungsten-containing layer does not strongly adhere, comprising the steps of
- depositing onto said substrate an insulating bonding layer selected from the group consisting of silicon oxides, silicon nitrides and silicon oxy-nitrides which adheres to said substrate, said bonding layer containing free silicon particles therein at least in a region close to the surface of said bonding layer to be contacted by said tungsten-containing layer,
- substituting atoms of tungsten for at least some of said free silicon in said bonding layer to produce buried tungsten inclusions in said bonding layer,
- the amount of said free silicon and said inclusions being sufficiently small that said bonding layer remains insulating, and
- depositing said tungsten-containing layer onto said bonding layer, said tungsten-containing layer adhering to said buried tungsten inclusions to form a strongly bonded tungsten-containing layer-bonding layer-substrate multilayer structure.
Dependencies are inferred from the claim text.