Substrate cleaning method, substrate cleaning apparatus and vacuum processing system
AssigneeTokyo Electron Limited
InventorsKazuya Dobashi, Kensuke Inai, Misako Saito
Life of this patent
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Abstract
In order to remove a deposit adhered to the backside of the peripheral portion of a wafer, a cleaning gas containing carbon dioxide gas is set to a pressure that is slightly lower than the pressure corresponding to a vapor pressure line of carbon dioxide at a temperature in the nozzle, and a gas cluster of carbon dioxide is generated. A gas cluster of carbon dioxide generated under such a condition is in a state immediately prior to undergoing a phase change to a liquid and therefore is a gas cluster having a large cluster diameter and having molecules that are firmly solidified.
Claims15
A substrate cleaning method for removing a deposit adhered to a backside or a peripheral portion of a substrate, the substrate cleaning method comprising:
- supporting a substrate by a support;
- adjusting and maintaining a pressure in a processing chamber to be a vacuum atmosphere;
- adjusting and maintaining a pressure inside a nozzle unit to be higher than the pressure in the processing chamber;
- and
- ejecting a cleaning gas containing a carbon dioxide gas to the backside or the peripheral portion of the substrate from the nozzle unit as an aggregate of atoms or molecules of carbon dioxide gas through adiabatic expansion to remove the deposit from the backside or the peripheral portion of the substrate,
- wherein the pressure inside the nozzle unit is set to be slightly lower than a pressure on a vapor pressure line of carbon dioxide at a temperature of the cleaning gas in the nozzle unit, so that a gas cluster is generated in a solidified state, and
- wherein the pressure inside the nozzle unit is higher than or equal to 75% and lower than 100% of the pressure on the vapor pressure line of carbon dioxide.
A substrate cleaning apparatus comprising:
- a support disposed in a processing chamber having a gas exhaust port and configured to support a substrate;
- a nozzle unit configured to eject a gas cluster to a backside or a peripheral portion of the substrate to remove a deposit adhered to the backside or the peripheral portion of the substrate being supported by the support;
- a gas supply unit configured to supply a cleaning gas containing carbon dioxide gas to the nozzle unit;
- a pressure controller configured to control a pressure in the nozzle unit;
- a moving mechanism configured to relatively move the nozzle unit and the support, and
- a control unit programmed to control the pressure controller and configured to:
- set a pressure in the processing chamber to be a vacuum atmosphere;
- and
- set a pressure inside the nozzle unit to be (1) slightly lower than a pressure on a vapor pressure line of carbon dioxide at a temperature of the cleaning gas in the nozzle unit and (2) higher than or equal to 75% and lower than 100% of the pressure on the vapor pressure line of carbon dioxide to generate the gas cluster in a solidified state.
Dependencies are inferred from the claim text.