Workpiece processing using ozone gas and chelating agents
First Claim
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1. A method for cleaning one or more workpieces comprising:
- placing the workpiece into a processing chamber, with an oxide layer on at least part of the workpiece;
introducing an aqueous liquid including a chelating agent onto the workpiece;
introducing ozone into the processing chamber;
with the ozone cleaning oxidizable contaminants from the workpiece, and with the chelating agent cleaning metal contaminants from the workpiece.
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Abstract
In systems and methods for cleaning a wafer having an oxide on a surface of the wafer, an aqueous liquid including a chelating agent is applied onto the wafer, while the wafer is also contacted by ozone gas. The ozone readily oxidizes the contaminants in the presence of the aqueous liquid. The chelating agent helps to remove metal contamination from the wafer, without the need for an acid such as hydrofluoric or hydrochloric acid. Etching of the oxide layer is accordingly reduced. The wafer can be effectively cleaned using aqueous liquid and ozone, while largely preserving the oxide layer needed for certain types of micro-scale devices formed on the wafer.
27 Citations
25 Claims
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1. A method for cleaning one or more workpieces comprising:
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placing the workpiece into a processing chamber, with an oxide layer on at least part of the workpiece;
introducing an aqueous liquid including a chelating agent onto the workpiece;
introducing ozone into the processing chamber;
with the ozone cleaning oxidizable contaminants from the workpiece, and with the chelating agent cleaning metal contaminants from the workpiece. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method for processing one or more workpieces having an oxide layer, comprising:
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heating a liquid including de-ionized water and a chelating agent;
forming a layer of the heated liquid on the surface of the workpiece; and
contacting the surface of the workpiece with ozone gas in the layer of heated liquid, with the ozone chemically reacting with an oxidizable contaminant at the surface of the workpiece, and with the chelating agent chemically reacting with a metal contaminant, to process the workpiece. - View Dependent Claims (15, 16, 17, 18, 19)
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20. A method for cleaning one or more workpieces having an oxide layer on a surface of the workpiece, comprising:
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placing the workpiece into a chamber;
heating a liquid including de-ionized water, ammonium hydroxide and a chelating agent;
forming a layer of the heated liquid on the surface of the workpiece; and
providing ozone gas into the chamber, with the ozone gas chemically reacting with a contaminant at the surface of the workpiece, and with the chelating agent chemically reacting with a metal contaminant, to process the workpiece, and with the oxide layer thickness remaining substantially unchanged.
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21. An apparatus for cleaning a workpiece comprising:
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a chamber;
a workpiece holder in the chamber;
liquid outlets in the chamber positioned to apply liquid onto at least one surface of a workpiece supported by the workpiece holder;
a source of aqueous liquid connecting with the liquid outlets, with the aqueous liquid including a chelating agent;
a heater for heating the aqueous liquid; and
a source of ozone gas connecting into the chamber. - View Dependent Claims (22, 23)
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24. Apparatus comprising:
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(a) means for forming a layer of a heated aqueous liquid on the surface of a workpiece, with the aqueous liquid including a chelating agent;
(b) means for supplying ozone gas to the surface of the workpiece, where the ozone oxidizes contamination on the surface to clean the workpiece. - View Dependent Claims (25)
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Specification