US6380096B2
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US
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In-situ integrated oxide etch process particularly useful for copper dual damascene
Assignee: Applied Materials Inc
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Filing: 1998-11-30
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Granted: 2002-04-30
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Expires: 2018-11-30
Abstract
Abstract An integrated in situ oxide etch process particularly useful for a counterbore dual-damascene structure over copper having in one inter-layer dielectric level a lower nitride stop layer, a lower oxide dielectric, a lower nitride stop layer, an upper oxide dielectric layer, and an anti-reflective coating (ARC). The process is divided into a counterbore etch and a trench etch with photolithography for each, and each step is preferably performed in a high-density plasma reactor having an inductively coupled plasma source primarily generating the plasma and a capacitively coupled pedestal supporting the wafer and producing the bias power. The counterbore etch preferably includes at least four substeps of opening the ARC, etching through the upper oxide and nitride layers, selectively etching the lower oxide layer but stopping on the lower nitride layer, and a post-etch treatment for removing residue. The trench etch preferably includes the five substeps of opening the ARC, etching through the upper oxide layer but stopping on the upper nitride layers, a first post-etch treatment for removing residue, a nitride removal of the exposed portions of the upper and lower nitride layers, and a second post-etch treatment for remaining further residues. The oxide etches selective to nitride are accomplished using a fluorocarbon chemistry with high bias and a high temperature for a silicon-based scavenger for fluorine placed next to the plasma. The nitride etches and removal are accomplished by adding an oxygen-containing gas to a fluorocarbon. The final nitride removal is accomplished with very low bias power to increase selectivity to nitride and reduce sputtering of the underlying copper. The post-etch treatments are oxygen plasmas with zero bias power.
Inventors
- 👤 Hoiman Hung
- 👤 Joseph P Caulfield
- 👤 Sum-Yee Betty Tang
- 👤 Jian Ding
- 👤 Tianzong Xu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 13:48
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/24; H10P50/242; H10P70/00; H10P70/20; H10P70/23; H10P70/234; H10P50/28; H10P50/282; H10P50/283; H10W; H10W20/00; H10W20/01; H10W20/071; H10W20/081; H10W20/084; H10W20/085; Y; Y10; Y10S; Y10S438/00; Y10S438/906; Y10S438/954
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
245 words
An integrated etch process performed upon a substrate having formed sequentially in an upward direction (a) a feature in said substrate to be contacted, (b) a first stop layer, (c) a first dielectric layer, and (d) a patterned mask, said process comprising the steps of: a first plasma etching step utilizing a first etching gas mixture comprising a first fluorocarbon etching gas and a carrier gas and operating with a first plasma source power and a first plasma bias power, wherein said first etching step etches through said first dielectric layer and stops on said first stop layer; and a first plasma treatment utilizing a first oxygen-containing gas and operating with a second plasma source power value and a second plasma bias power value that is effectively zero, said first plasma treatment removing polymeric residues produced by said first fluorocarbon etching gas; a second plasma etching step utilizing a second etching gas mixture comprising a second fluorocarbon etching gas and an oxygen-containing gas and operating with a third plasma source power value and a third plasma bias power value less than said first plasma bias power value, said second plasma etching step removing an exposed portion of said first stop layer; and a second plasma treatment utilizing a second oxygen-containing gas and operating with a fourth plasma source power value and a fourth plasma bias power value that is effectively zero, said second plasma treatment removing polymeric residues produced by said second fluorocarbon etching gas.
Claim 2
Dependent Claim
245 words
An integrated etch process performed upon a substrate having formed sequentially in an upward direction (a) a feature in said substrate to be contacted, (b) a first stop layer, (c) a first dielectric layer, and (d) a patterned mask, said process comprising the steps of: a first plasma etching step utilizing a first etching gas mixture comprising a first fluorocarbon etching gas and a carrier gas and operating with a first plasma source power and a first plasma bias power, wherein said first etching step etches through said first dielectric layer and stops on said first stop layer; and a first plasma treatment utilizing a first oxygen-containing gas and operating with a second plasma source power value and a second plasma bias power value that is effectively zero, said first plasma treatment removing polymeric residues produced by said first fluorocarbon etching gas; a second plasma etching step utilizing a second etching gas mixture comprising a second fluorocarbon etching gas and an oxygen-containing gas and operating with a third plasma source power value and a third plasma bias power value less than said first plasma bias power value, said second plasma etching step removing an exposed portion of said first stop layer; and a second plasma treatment utilizing a second oxygen-containing gas and operating with a fourth plasma source power value and a fourth plasma bias power value that is effectively zero, said second plasma treatment removing polymeric residues produced by said second fluorocarbon etching gas.
Claim 3
Dependent Claim
21 words
The process of claim 1 , wherein said first dielectric layer comprises an oxide and said stop layer comprises a nitride.
Claim 4
Dependent Claim
14 words
The process of claim 2 , wherein said second fluorocarbon etching gas comprises monofluoromethane.
Claim 5
Dependent Claim
13 words
The process of claim 3 , wherein said oxygen-containing gas is oxygen gas.
Claim 6
Dependent Claim
72 words
The process of claim 1 , wherein said substrate further comprises an anti-reflection coating disposed between said patterned mask and said first dielectric layer, said process further comprising a third plasma etching step performed before said first plasma etching step of utilizing a third etching gas mixture comprising an oxygen-containing gas, a fluorocarbon gas, and a carrier gas with a fifth plasma source power value and a fifth plasma bias power value.
Claim 7
Dependent Claim
16 words
The process of claim 5 , wherein said third etching step further comprises utilizing a fluorocarbon.
Claim 8
Dependent Claim
14 words
The process of claim 6 , wherein said anti-reflective coating comprises an organic polymer.
Claim 9
Dependent Claim
13 words
The process of claim 5 , wherein said anti-reflective coating comprises silicon oxynitride.
Claim 10
Dependent Claim
29 words
The process of claim 1 , wherein said integrated etch process is performed in a single plasma etch reactor having separately controlled plasma source power and plasma bias power.
Claim 11
Dependent Claim
30 words
The process of claim 1 , wherein during said second plasma treatment step said fourth plasma bias power value is maintained as long as said second oxygen-containing gas is supplied.
Claim 12
Dependent Claim
20 words
The process of claim 1 , wherein said first plasma treatment step removes any remaining portion of said patterned mask.
Claim 13
Dependent Claim
17 words
The process of claim 1 , wherein said second plasma etching step additionally utilizes a carrier gas.
Claim 14
Dependent Claim
243 words
An integrated etch process for a counterbore dual-damascene structure comprising: a counterbore via etch performed upon a substrate having formed sequentially in an upward direction a lower nitride layer, an upper oxide dielectric layer, a first anti-reflective coating, and a first mask patterned for via hole; and a trench etch performed upon said substrate after said counterbore via etch and having formed over said upper oxide layer a second anti-reflective coating and a second mask patterned for a trench surrounding said via hole; wherein said counterbore via etch comprises opening said first anti-reflective coating, etching through said upper oxide layer and said upper nitride layer, etching through said lower oxide layer but stopping on said lower nitride layer with an etching gas comprising a fluorocarbon and argon, and a first post-etch treatment using an oxygen plasma; and wherein said trench etch comprises opening said second anti-reflective coating, etching through said upper oxide layer but stopping on said upper nitride layer with an etching gas comprising a fluorocarbon and a chemically inactive gas and with a first plasma bias power value, a second post-etch treatment using an oxygen plasma, etching through said upper nitride layer with an etching gas comprising a fluorocarbon, an oxygen-containing gas, and a chemically inactive gas and with a second plasma bias power value substantially less than said first plasma bias power value, and a third post-etch treatment using an oxygen plasma and effectively a zero plasma bias power value.
Claim 15
Dependent Claim
243 words
An integrated etch process for a counterbore dual-damascene structure comprising: a counterbore via etch performed upon a substrate having formed sequentially in an upward direction a lower nitride layer, an upper oxide dielectric layer, a first anti-reflective coating, and a first mask patterned for via hole; and a trench etch performed upon said substrate after said counterbore via etch and having formed over said upper oxide layer a second anti-reflective coating and a second mask patterned for a trench surrounding said via hole; wherein said counterbore via etch comprises opening said first anti-reflective coating, etching through said upper oxide layer and said upper nitride layer, etching through said lower oxide layer but stopping on said lower nitride layer with an etching gas comprising a fluorocarbon and argon, and a first post-etch treatment using an oxygen plasma; and wherein said trench etch comprises opening said second anti-reflective coating, etching through said upper oxide layer but stopping on said upper nitride layer with an etching gas comprising a fluorocarbon and a chemically inactive gas and with a first plasma bias power value, a second post-etch treatment using an oxygen plasma, etching through said upper nitride layer with an etching gas comprising a fluorocarbon, an oxygen-containing gas, and a chemically inactive gas and with a second plasma bias power value substantially less than said first plasma bias power value, and a third post-etch treatment using an oxygen plasma and effectively a zero plasma bias power value.
Claim 16
Dependent Claim
63 words
The process of claim 13 , wherein said counterbore via etch is performed in a single first plasma etch reactor having separately controlled plasma source power and plasma bias power and wherein said trench etch is performed in a single second plasma etch reactor, which may be the same as said first reactor, having separately controlled plasma source power and plasma bias power.
Claim 17
Dependent Claim
134 words
The process of claim 13 , wherein said step in said counterbore via etch of etching through said upper oxide layer and said upper nitride layer utilizes a first etching mixture comprising a first fluorocarbon etch gas and a carrier gas and operating with a first plasma source power and a first plasma bias power; further comprising an effectively immediately following first plasma treatment utilizing a first oxygen-containing gas and operating with a second plasma source power value and a second plasma bias power value that is effectively zero; and wherein said step in said counterbore via etch of etching through said lower oxide layer additionally utilizes an oxygen-containing gas and operating with a third plasma source power value and a third plasma bias power value less than said first plasma bias power value.
Claim 18
Dependent Claim
21 words
The process of claim 13 , wherein said first post-etch treatment operates with a bias power value that is effectively zero.
Claim 19
Dependent Claim
160 words
An integrated etch process performed in a single plasma etch reactor having separately controlled plasma source power and plasma bias power and performed upon a substrate having formed sequentially in an upward direction (a) a stop layer, (b) a first first dielectric layer, and (c) an anti-reflection coating, said process comprising the steps of: opening the anti-reflection coating with a first oxygen-containing plasma of a first gas mixture comprising a first oxygen-containing gas and a first fluorocarbon gas; selectively etching said dielectric layer with a plasma of a second gas mixture comprising a second fluorocarbon gas and a larger amount of a chemically inactive gas and using a first plasma bias power value, said etching stopping on said stop layer; removing said stop layer with a second oxygen-containing plasma and using a second plasma bias power value; and a subsequent plasma treatment utilizing a third oxygen-containing plasma, wherein said plasma bias power applied during said plasma treatment is effectively zero.
Claim 20
Dependent Claim
160 words
An integrated etch process performed in a single plasma etch reactor having separately controlled plasma source power and plasma bias power and performed upon a substrate having formed sequentially in an upward direction (a) a stop layer, (b) a first first dielectric layer, and (c) an anti-reflection coating, said process comprising the steps of: opening the anti-reflection coating with a first oxygen-containing plasma of a first gas mixture comprising a first oxygen-containing gas and a first fluorocarbon gas; selectively etching said dielectric layer with a plasma of a second gas mixture comprising a second fluorocarbon gas and a larger amount of a chemically inactive gas and using a first plasma bias power value, said etching stopping on said stop layer; removing said stop layer with a second oxygen-containing plasma and using a second plasma bias power value; and a subsequent plasma treatment utilizing a third oxygen-containing plasma, wherein said plasma bias power applied during said plasma treatment is effectively zero.
Claim 21
Dependent Claim
15 words
The process of claim 17 , wherein said selectively etching step produces a high-density plasma.
Claim 22
Dependent Claim
15 words
The process of claim 17 , wherein said second fluorocarbon gas comprises a hydrogen-free fluorocarbon.
Claim 23
Dependent Claim
14 words
The process of claim 17 , wherein said first gas mixture additionally comprises argon.
Claim 24
Dependent Claim
14 words
The process of claim 17 , wherein said anti-reflection coating comprises an organic polymer.
Claim 25
Dependent Claim
13 words
The process of claim 17 , wherein said anti-reflection coating comprises silicon oxynitride.
Claim 26
Dependent Claim
21 words
The process of claim 17 , wherein said third oxygen-containing plasma is formed from a gas consisting essentially of oxygen gas.
Claim 27
Dependent Claim
22 words
The process of claim 17 , wherein said first plasma bias power value is less than said first plasma bias power value.
References Cited (Backward Citations)
US5143820A
Cited
EP0721205A2
Cited
US5744293A
Cited
US5997757A
Cited
US5910453A
Cited
US5843847A
Cited
US6090697A
Cited
US5965463A
Cited
US6051504A
Cited
US5935762A
Cited
US6057247A
Cited
US6027959A
Cited
US5994227A
Cited
US6037213A
Cited
US6037266A
Cited
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