摘要:
A copper metallization structure and its method of formation in which a layer of a copper alloy, such as Cu—Mg or Cu—Al is deposited over a silicon oxide based dielectric layer and a substantially pure copper layer is deposited over the copper alloy layer. The copper alloy layer serves as a seed or wetting layer for subsequent filling of via holes and trenches with substantially pure copper. Preferably, the copper alloy is deposited cold in a sputter process, but, during the deposition of the pure copper layer or afterwards in a separate annealing step, the temperature is raised sufficiently high to cause the alloying element of the copper alloy to migrate to the dielectric layer and form a barrier there against diffusion of copper into and through the dielectric layer. This barrier also promotes adhesion of the alloy layer to the dielectric layer, thereby forming a superior wetting and seed layer for subsequent copper full-fill techniques. Filling of the alloy-lined feature can be accomplished using PVD, CVD, or electro/electroless plating.
摘要:
A copper via structure formed when copper and a small amount of an alloying metal such as magnesium or aluminum are cosputtered onto a substrate having oxide on at least a portion of its surface. Either the wafer is held at an elevated temperature during deposition or the sputtered film is annealed without the wafer being exposed to ambient. Due to the high temperature, the alloying metal diffuses to the surface. If a surface is exposed to a low partial pressure of oxygen or contacts silicon dioxide, the magnesium or aluminum forms a thin stable oxide but also extends into the oxide a distance of about 100 nm. The alloying metal oxide having a thickness of about 6 nm on the oxide sidewalls encapsulates the copper layer to provide a barrier against copper migration, to form an adhesion layer over silicon dioxide, and to act as a seed layer for the later growth of copper, for example, by electroplating.
摘要:
A copper metallization structure in which a layer of a copper alloy, such as Cu--Mg or Cu--Al is deposited over a silicon oxide based dielectric layer and a substantially pure copper layer is deposited over the copper alloy layer. The copper alloy layer serves as a seed or wetting layer for subsequent filling of via holes and trenches with substantially pure copper. Preferred examples of the alloying elements and their atomic alloying percentage include magnesium between 0.05 and 6% and aluminum between 0.05 and 0.3%. Further examples include boron, tantalum, tellurium, and titanium. Preferably, the copper alloy is deposited cold in a sputter process, but, during the deposition of the pure copper layer or afterwards in a separate annealing step, the temperature is raised sufficiently high to cause the alloying element of the copper alloy to migrate to the dielectric layer and form a barrier there against diffusion of copper into and through the dielectric layer. This barrier also promotes adhesion of the alloy layer to the dielectric layer, thereby forming a superior wetting and seed layer for subsequent copper full-fill techniques. Filling of the alloy-lined feature can be accomplished using PVD, CVD, or electro/electroless plating.
摘要:
Copper and a small amount of an alloying metal such as magnesium or aluminum are cosputtered onto a substrate having oxide on at least a portion of its surface. Either the wafer is held at an elevated temperature during deposition or the sputtered film is annealed without the wafer being exposed to ambient. Due to the high temperature, the alloying metal diffuses to the surface. If a surface is exposed to a low partial pressure of oxygen or contacts silicon dioxide, the magnesium or aluminum forms a thin stable oxide. The alloying metal oxide encapsulates the copper layer to provide a barrier against copper migration, to form an adhesion layer over silicon dioxide, and to act as a seed layer for the later growth of copper, for example, by electroplating.
摘要:
Metallization process sequences are provided for forming reliable interconnects including lines, vias and contacts. An initial barrier layer, such as Ta or TaN, is first formed on a patterned substrate followed by seed layer formed using high density plasma PVD techniques. The structure is then filled using either 1) electroplating, 2) PVD reflow, 3) CVD followed by PVD reflow, or 4) CVD.
摘要:
Metallization process sequences are provided for forming reliable interconnects including lines, vias and contacts. An initial barrier layer, such as Ta or TaN, is first formed on a patterned substrate followed by seed layer formed using high density plasma PVD techniques. The structure is then filled using either 1) electroplating, 2) PVD reflow, 3) CVD followed by PVD reflow, or 4) CVD.
摘要:
A method and apparatus for metallization process sequences are provided for forming reliable interconnects including lines, vias and contacts. An initial barrier layer, such as Ta or TaN, is first formed on a patterned substrate followed by seed layer formed using high density plasma PVD techniques. The structure is then filled using either 1) electroplating, 2) PVD reflow, 3) CVD followed by PVD reflow, or 4) CVD.
摘要:
One aspect of the invention provides a consistent metal electroplating technique to form void-less metal interconnects in sub-micron high aspect ratio features on semiconductor substrates. One embodiment of the invention provides a method for filling sub-micron features on a substrate, comprising reactive precleaning the substrate, depositing a barrier layer on the substrate using high density plasma physical vapor deposition; depositing a seed layer over the barrier layer using high density plasma physical vapor deposition; and electro-chemically depositing a metal using a highly resistive electrolyte and applying a first current density during a first deposition period followed by a second current density during a second period.
摘要:
Methods of forming copper interconnects free from via-to-via leakage currents and having low resistances are disclosed. In a first aspect, a barrier layer is deposited on the first metal layer prior to copper oxide sputter-etching to prevent copper atoms from reaching the interlayer dielectric and forming via-to-via leakage current paths therein. In a second aspect, a capping dielectric barrier layer is deposited over the first metal layer prior to sputter etching. During sputter-etching, the capping dielectric barrier layer redistributes on the sidewalls of the interlayer dielectric, preventing sputter-etched copper atoms from reaching the interlayer dielectric and forming via-to-via leakage paths therein. In a third aspect, both a capping dielectric barrier layer and a barrier layer are deposited over the first metal layer prior to sputter-etching to prevent copper atoms produced during sputter-etching from reaching the interlayer dielectric and forming via-to-via leakage paths therein.
摘要:
Methods of forming copper interconnects free from via-to-via leakage currents and having low resistances are disclosed. In a first aspect, a barrier layer is deposited on the first metal layer prior to copper oxide sputter-etching to prevent copper atoms from reaching the interlayer dielectric and forming via-to-via leakage current paths therein. In a second aspect, a capping dielectric barrier layer is deposited over the first metal layer prior to sputter etching. During sputter-etching, the capping dielectric barrier layer redistributes on the sidewalls of the interlayer dielectric, preventing sputter-etched copper atoms from reaching the interlayer dielectric and forming via-to-via leakage paths therein. In a third aspect, both a capping dielectric barrier layer and a barrier layer are deposited over the first metal layer prior to sputter-etching to prevent copper atoms produced during sputter-etching from reaching the interlayer dielectric and forming via-to-via leakage paths therein.