Remote plasma pre-clean with low hydrogen pressure
First Claim
1. A method of plasma processing a substrate containing a dielectric layer, comprising the steps of:
- disposing the substrate in a vacuum chamber to which is attached a remote plasma source;
passing a reducing processing gas through the remote plasma sources;
magnetically filtering out ions in the processing gas delivered from the output from the remote plasma source and thence passing the processing gas into the chamber, the processing gas comprising hydrogen and substantially no oxygen or water; and
during the filtering and passing step, maintaining a pressure within the chamber such that a hydrogen partial pressure in the chamber is less than 150 milliTorr and greater than 10 milliTorr.
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Accused Products
Abstract
A plasma cleaning method particularly useful for removing photoresist and oxide residue from a porous low-k dielectric with a high carbon content prior to sputter deposition. A remote plasma source produces a plasma primarily of hydrogen radicals. The hydrogen pressure may be kept relatively low, for example, at 30 milliTorr. Optionally, helium may be added to the processing gas with the hydrogen partial pressure held below 150 milliTorr. Superior results are obtained with 70% helium in 400 milliTorr of hydrogen and helium. Preferably, an ion filter, such as a magnetic filter, removes hydrogen and other ions from the output of the remote plasma source and a supply tube from the remote plasma source includes a removable dielectric liner in combination with dielectric showerhead and manifold liner.
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Citations
15 Claims
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1. A method of plasma processing a substrate containing a dielectric layer, comprising the steps of:
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disposing the substrate in a vacuum chamber to which is attached a remote plasma source; passing a reducing processing gas through the remote plasma sources; magnetically filtering out ions in the processing gas delivered from the output from the remote plasma source and thence passing the processing gas into the chamber, the processing gas comprising hydrogen and substantially no oxygen or water; and during the filtering and passing step, maintaining a pressure within the chamber such that a hydrogen partial pressure in the chamber is less than 150 milliTorr and greater than 10 milliTorr. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of plasma processing a substrate, comprising the steps of:
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disposing the substrate in a vacuum chamber to which is attached a remote plasma source; passing a reducing processing gas through the remote plasma source and thence into the vacuum chamber, the processing gas comprising hydrogen and a noble gas and substantially no oxygen or water; and during the passing step, maintaining in the vacuum chamber a total pressure of between 300 and 500 milliTorr and a partial pressure of hydrogen of between 80 and 150 milliTorr. - View Dependent Claims (9, 10, 11, 12)
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13. A method of plasma processing a substrate containing a porous dielectric layer with a hole etched therein, sidewalls of the hole being covered by no more than residues resulting from the etching, comprising the steps of:
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disposing the substrate in a vacuum chamber to which is attached a remote plasma source; passing a reducing processing gas through the remote plasma source and thence into the vacuum chamber, the processing gas comprising hydrogen and substantially no oxygen or water; and during the passing step, maintaining a pressure within the chamber such that a hydrogen partial pressure in the chamber is less than 120 milliTorr and greater than 20 milliTorr. - View Dependent Claims (14, 15)
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Specification