US6423629B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multilevel copper interconnects with low-k dielectrics and air gaps
Assignee: Round Rock Research LLC
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Filing: 2000-05-31
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Granted: 2002-07-23
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Expires: 2020-05-31
Abstract
Abstract Structures and methods are provided for an improved multilevel wiring interconnect in an integrated circuit assembly. The present invention provides for a multilayer copper wiring structure by electroless, selectively deposited copper in a streamlined process which further reduces both intra-level line to line capacitance and the inter-level capacitance. In particular, an illustrative embodiment of the present invention includes a novel methodology for forming multilevel wiring interconnects in an integrated circuit assembly. The method includes forming a number of multilayer metal lines, e.g. copper lines formed by selective electroless plating, separated by air gaps above a substrate. A low dielectric constant material is deposited between the number of metal lines and the substrate using a directional process. According to the teachings of the present invention, using a directional process includes maintaining a number of air gaps in the low dielectric constant material. Structures and systems are similarly included in the present invention.
Inventors
- 👤 Kie Y. Ahn
- 👤 Leonard Forbes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:28
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/056; H10W20/057; H10W20/063; H10W20/071; H10W20/072; H10W20/40; H10W20/41; H10W20/425; H10W20/45; H10W20/46; H10W20/47; H10W20/495
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
70 words
A method for forming multilevel wiring interconnects in an integrated circuit assembly, comprising: forming a number of multilayer metal lines separated by air gaps above a substrate; depositing a low dielectric constant material between the number of metal lines and the substrate using a directional process; and wherein using a directional process includes maintaining a number of air gaps in the low dielectric constant ma to the multilayer metal lines.
Claim 2
Independent Claim
70 words
A method for forming multilevel wiring interconnects in an integrated circuit assembly, comprising: forming a number of multilayer metal lines separated by air gaps above a substrate; depositing a low dielectric constant material between the number of metal lines and the substrate using a directional process; and wherein using a directional process includes maintaining a number of air gaps in the low dielectric constant ma to the multilayer metal lines.
Claim 3
Dependent Claim
35 words
The method of claim 1 , wherein depositing a low dielectric constant material between the number of metal lines and the substrate using a directional process includes using a microwave plasma-assisted supersonic jet deposition process.
Claim 4
Dependent Claim
19 words
The method of claim 1 , wherein depositing a low dielectric constant material includes depositing an organic silica film.
Claim 5
Dependent Claim
35 words
The method of claim 1 , wherein depositing a low dielectric constant material between the number of metal lines and the substrate using a directional process includes using a quasi hydrogen-free chemical vapor deposition process.
Claim 6
Dependent Claim
43 words
The method of claim 1 , wherein depositing a low dielectric constant material between the number of metal lines and the substrate using a directional process includes forming a low dielectric constant film by radio frequency plasma enhanced chemical vapor deposition using tetramethylsilane.
Claim 7
Dependent Claim
42 words
The method of claim 1 , wherein depositing a low dielectric constant material between the number of metal lines and the substrate using a directional process includes depositing a polymer-like organic thin film by plasma-enhanced chemical vapor deposition using a para-xylene precursor.
Claim 8
Independent Claim
79 words
A method for forming multilevel wiring interconnects in an integrated circuit assembly, comprising: forming a number of multilayer metal lines separated by air gaps above a substrate; depositing a low dielectric constant material, having a dielectric constant of less than 2.7, between the number of metal lines and the substrate using a directional process; and wherein using a directional process includes maintaining a number of air gaps in the low dielectric constant material adjacent to the multilayer metal lines.
Claim 9
Independent Claim
79 words
A method for forming multilevel wiring interconnects in an integrated circuit assembly, comprising: forming a number of multilayer metal lines separated by air gaps above a substrate; depositing a low dielectric constant material, having a dielectric constant of less than 2.7, between the number of metal lines and the substrate using a directional process; and wherein using a directional process includes maintaining a number of air gaps in the low dielectric constant material adjacent to the multilayer metal lines.
Claim 10
Dependent Claim
43 words
The method of claim 7 , wherein depositing a low dielectric constant material, having a dielectric constant of less than 2.7, between the number of metal lines and the substrate using a directional process includes using a microwave plasma-assisted supersonic jet deposition process.
Claim 11
Dependent Claim
27 words
The method of claim 7 , wherein depositing a low dielectric constant material, having a dielectric constant of less than 2.7, includes depositing an organic silica film.
Claim 12
Dependent Claim
43 words
The method of claim 7 , wherein depositing a low dielectric constant material, having a dielectric constant of less than 2.7, between the number of metal lines and the substrate using a directional process includes using a quasi hydrogen-free chemical vapor deposition process.
Claim 13
Dependent Claim
50 words
The method of claim 7 , wherein depositing a low dielectric constant material, having a dielectric constant of less than 2.7, between the number of metal lines and the substrate using a directional process includes depositing a polymer-like organic thin film by plasma-enhance chemical vapor deposition using a para-xylene precursor.
Claim 14
Independent Claim
73 words
A method for forming multilevel wiring interconnects in an integrated circuit assembly, comprising: forming a number of multilayer metal lines separated by air gaps above a substrate; depositing a low dielectric constant material between the number of metal lines and the substrate using a quasi hydrogen-free chemical vapor deposition process; and wherein using a quasi hydrogen-free chemical vapor deposition process includes maintaining a number of air gaps in the low dielectric constant material.
Claim 15
Independent Claim
73 words
A method for forming multilevel wiring interconnects in an integrated circuit assembly, comprising: forming a number of multilayer metal lines separated by air gaps above a substrate; depositing a low dielectric constant material between the number of metal lines and the substrate using a quasi hydrogen-free chemical vapor deposition process; and wherein using a quasi hydrogen-free chemical vapor deposition process includes maintaining a number of air gaps in the low dielectric constant material.
Claim 16
Dependent Claim
32 words
The method of claim 12 , wherein using a quasi hydrogen-free chemical vapor deposition process includes using a mixture of tetra-iso-cyanate silane, di-methyl silyl di-iso-cyanate silane, and tri-methyl amine by successive fluorination.
Claim 17
Dependent Claim
60 words
The method of claim 13 , wherein using a mixture of tetra-iso-cyanate silane, di-methyl silyl di-iso-cyanate silane, and tri-methyl amine by successive fluorination includes creating a film in which of a set of methyl groups and a fluorine group of atoms are as much as 43% and 9% respectively of that for a content of silicon atoms in the film.
Claim 18
Dependent Claim
15 words
The method of claim 13 , wherein the method further includes vacuum annealing the film.
Claim 19
Dependent Claim
30 words
The method of claim 12 , wherein depositing a low dielectric constant material includes depositing a low dielectric constant material which has a dielectric constant (k) of less than 2.7.
Claim 20
Independent Claim
227 words
A method for forming multilevel wiring interconnects in an integrated circuit assembly, comprising: depositing a first seed layer including a thin film of Palladium (Pd) or Copper (Cu) on a substrate; depositing a first patterned photoresist layer, wherein depositing the first patterned photoresist layer defines a number of via holes above the first seed layer; forming a first layer of copper using electroless plating, wherein forming the first layer of copper using electroless plating includes filling the number of via holes to a top surface of the first patterned photoresist layer; depositing a second seed layer including a thin film of Palladium (Pd) Copper (Cu) on the first layer of copper and the top surface of the photoresist layer; depositing a second patterned photoresist layer, wherein depositing the second patterned photoresist layer defines a number of conductor line openings above the second seed layer; forming a second layer of copper using electroless plating, wherein depositing a second layer of copper using electroless plating includes filling the number of conductor line openings to a top surface of the second patterned photoresist layer; removing the patterned photoresist layers using oxygen plasma ashing; depositing a low dielectric constant material between the layers of copper and the substrate using a directional process; and wherein using a directional process includes maintaining a number of air gaps in the low dielectric constant material.
Claim 21
Independent Claim
227 words
A method for forming multilevel wiring interconnects in an integrated circuit assembly, comprising: depositing a first seed layer including a thin film of Palladium (Pd) or Copper (Cu) on a substrate; depositing a first patterned photoresist layer, wherein depositing the first patterned photoresist layer defines a number of via holes above the first seed layer; forming a first layer of copper using electroless plating, wherein forming the first layer of copper using electroless plating includes filling the number of via holes to a top surface of the first patterned photoresist layer; depositing a second seed layer including a thin film of Palladium (Pd) Copper (Cu) on the first layer of copper and the top surface of the photoresist layer; depositing a second patterned photoresist layer, wherein depositing the second patterned photoresist layer defines a number of conductor line openings above the second seed layer; forming a second layer of copper using electroless plating, wherein depositing a second layer of copper using electroless plating includes filling the number of conductor line openings to a top surface of the second patterned photoresist layer; removing the patterned photoresist layers using oxygen plasma ashing; depositing a low dielectric constant material between the layers of copper and the substrate using a directional process; and wherein using a directional process includes maintaining a number of air gaps in the low dielectric constant material.
Claim 22
Dependent Claim
25 words
The method of claim 17 , wherein depositing a seed layer includes depositing a seed layer having a thickness of less than 15 nanometers (nm).
Claim 23
Dependent Claim
25 words
The method of claim 17 , wherein depositing a seed layer includes forming a discontinuous island structure on the substrate using a sputtering deposition technique.
Claim 24
Dependent Claim
30 words
The method of claim 17 , wherein depositing a low dielectric constant material includes depositing a low dielectric constant material which has a dielectric constant (k) of less than 2.7.
Claim 25
Dependent Claim
35 words
The method of claim 17 , wherein depositing a low dielectric constant material between the number of copper layers and the substrate using a directional process includes using a microwave plasma-assisted supersonic jet deposition process.
Claim 26
Dependent Claim
19 words
The method of claim 17 , wherein depositing a low dielectric constant material includes depositing an organic silica film.
Claim 27
Dependent Claim
35 words
The method of claim 17 , wherein depositing a low dielectric constant material between the number of copper layers and the substrate using a directional process includes using a quasi hydrogen-free chemical vapor deposition process.
Claim 28
Dependent Claim
43 words
The method of claim 17 , wherein depositing a low dielectric constant material between the number of copper layers and the substrate using a directional process includes forming a low dielectric constant film by radio frequency plasma enhanced chemical vapor deposition using tetramethylsilane.
Claim 29
Dependent Claim
42 words
The method of claim 17 , wherein depositing a low dielectric constant material between the number of copper layers and the substrate using a directional process includes depositing a polymer-like organic thin film by plasma-enhance chemical vapor deposition using a para-xylene precursor.
Claim 30
Independent Claim
216 words
A method for forming a multilayer copper wiring structure, comprising: depositing a first seed layer on a substrate; patterning a first photoresist layer over the first seed layer to define a number of via holes opening to the first seed layer; forming a first level of copper vias in the number of via holes using electroless plating; depositing a second seed layer on the first level of copper vias and first photoresist layer; patterning a second photoresist layer over the second seed layer to define a number of conductor line openings to the second seed layer; forming a first level of conductor lines in the number of conductor line openings using electroless plating; depositing a third seed layer on the first level of conductor lines and the second photoresist layer; patterning a third photoresist layer over the third seed layer to define a number of via holes opening to the third seed layer; and forming a second level of copper vias in the number of via holes using electroless plating; removing the patterned photoresist layers using oxygen plasma ashing; depositing a low dielectric constant material between the layers of copper and the substrate using a directional process; and wherein using a directional process includes maintaining a number of air gaps in the low dielectric constant material.
Claim 31
Independent Claim
216 words
A method for forming a multilayer copper wiring structure, comprising: depositing a first seed layer on a substrate; patterning a first photoresist layer over the first seed layer to define a number of via holes opening to the first seed layer; forming a first level of copper vias in the number of via holes using electroless plating; depositing a second seed layer on the first level of copper vias and first photoresist layer; patterning a second photoresist layer over the second seed layer to define a number of conductor line openings to the second seed layer; forming a first level of conductor lines in the number of conductor line openings using electroless plating; depositing a third seed layer on the first level of conductor lines and the second photoresist layer; patterning a third photoresist layer over the third seed layer to define a number of via holes opening to the third seed layer; and forming a second level of copper vias in the number of via holes using electroless plating; removing the patterned photoresist layers using oxygen plasma ashing; depositing a low dielectric constant material between the layers of copper and the substrate using a directional process; and wherein using a directional process includes maintaining a number of air gaps in the low dielectric constant material.
Claim 32
Dependent Claim
30 words
The method of claim 26 , wherein depositing a low dielectric constant material includes depositing a low dielectric constant material which has a dielectric constant (k) of less than 2.7.
Claim 33
Dependent Claim
35 words
The method of claim 26 , wherein depositing a low dielectric constant material between the number of copper layers and the substrate using a directional process includes using a microwave plasma-assisted supersonic jet deposition process.
Claim 34
Dependent Claim
19 words
The method of claim 26 , wherein depositing a low dielectric constant material includes depositing an organic silica film.
Claim 35
Dependent Claim
35 words
The method of claim 26 , wherein depositing a low dielectric constant material between the number of copper layers and the substrate using a directional process includes using a quasi hydrogen-free chemical vapor deposition process.
Claim 36
Dependent Claim
43 words
The method of claim 26 , wherein depositing a low dielectric constant material between the number of copper layers and the substrate using a directional process includes forming a low dielectric constant film by radio frequency plasma enhanced chemical vapor deposition using tetramethylsilane.
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