Refractory metal capped low resistivity metal conductor lines and vias
First Claim
1. A device, comprising:
- a substrate;
at least one dielectric layer positioned on said substrate; and
metalization positioned in an opening in said at least one dielectric layer and extending from a surface which is substantially co-planar with a surface of said at least one dielectric layer towards said substrate,said metalization comprised of a low resistivity metal or alloy and being encapsulated by at least one refractory metal or alloy,said low resistivity metal or alloy having side walls which taper inwardly towards one another towards said surface of said metalization which is planar with said surface of said at least one dielectric layer,wherein said at least one refractory metal or alloy comprises an alloy containing silicon and has a higher incorporated silicon content at a location near said surface of said metalization present as one of a distinct and graded composition than at a location closer to said substrate.
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Accused Products
Abstract
A contact structure for a semiconductor device having a first refractory metal layer formed only at the bottom of a contact hole. The first refractory metal is selected from a group comprising titanium (Ti), titanium alloys or compounds such as Ti/TiN, tungsten (W), titanium/tungsten (Ti/W) alloys, or chromium (Cr) or tantalum (Ta) and their alloys or some other suitable material. A low resistivity layer comprising a single, binary or ternary metalization is deposited over the first refractory metal layer in the contact hole by a method such as PVD using evaporation or collimated sputtering. The low resistivity layer has side walls which taper inwardly toward one another with increasing height of the layer and the low resistivity layer does not contact the side walls of the contact hole. The low resistivity layer may be Alx Cuy (x+y=1; x≧0, y≧0), ternary alloys such as Al-Pd-Cu or multicomponent alloys such as Al-Pd-Nb-Au. A second refractory metal layer is deposited over the low resistivity layer. The second refractory metal layer may be tungsten, cobalt, nickel, molybdenum or alloys/compounds such as Ti/TiN. The first and second refractory metal layers completely encapsulate the low resistivity layer. The first and second refractory metal layers can comprise an alloy containing silicon with a higher incorporated silicon content near the top of the contact hold present as a distinct or graded composition than at a location closer to the bottom of the contact hole.
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Citations
9 Claims
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1. A device, comprising:
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a substrate; at least one dielectric layer positioned on said substrate; and metalization positioned in an opening in said at least one dielectric layer and extending from a surface which is substantially co-planar with a surface of said at least one dielectric layer towards said substrate, said metalization comprised of a low resistivity metal or alloy and being encapsulated by at least one refractory metal or alloy, said low resistivity metal or alloy having side walls which taper inwardly towards one another towards said surface of said metalization which is planar with said surface of said at least one dielectric layer, wherein said at least one refractory metal or alloy comprises an alloy containing silicon and has a higher incorporated silicon content at a location near said surface of said metalization present as one of a distinct and graded composition than at a location closer to said substrate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification