Method of measuring gas purity information, chamber unit and exposure unit using the method and a device production method
AssigneeCanon Kabushiki Kaisha
InventorsTakayuki Hasegawa, Hidehiko Fujioka
Life of this patent
Estimating the term…
Abstract
The sonic velocity in a chamber which is filled with helium is measured by using ultrasonic waves, and the temperature in the chamber is also measured. Purity information relating to helium gas contained in the chamber is determined on the basis of the measured values of the sonic velocity and the temperature.
Claims26
A method of measuring purity information relating to gas contained in a closed space, said method comprising:
- generating ultrasonic waves in the gas contained in the closed space;
- measuring values of the sonic velocity in the gas at a plurality of positions in the closed space;
- and
- determining purity information relating to the gas in the closed space on the basis of the measured values.
A chamber unit for measuring purity information relating to gas contained in a closed space, comprising:
- an airtight chamber having a closed space for containing gas;
- means for generating ultrasonic waves in the gas contained in said closed space;
- sonic velocity measurement means for measuring values of the sonic velocity in the gas at a plurality of positions in said chamber;
- and
- determination means for determining purity information relating to the gas in said chamber, on the basis of the values measured by said sonic velocity measurement means.
An exposure unit comprising:
- an airtight chamber containing a substrate in a gaseous ambience;
- exposing means for exposing said substrate to an interactive energy field or source;
- means for generating ultrasonic waves in the gas contained in said chamber;
- sonic velocity measurement means for measuring values of the sonic velocity in the gas at a plurality of positions in said chamber;
- and
- determination means for determining purity information relating to the gas in said chamber, on the basis of the values measured by said sonic velocity measurement means.
A device production method comprising the steps of:
- containing a substrate in a gaseous ambience in a chamber;
- generating ultrasonic waves in the gas contained in the chamber;
- measuring values of the sonic velocity in the gas at a plurality of positions in the chamber;
- determining purity information relating to the gas in the chamber, on the basis of the measure values of the sonic velocity;
- and
- transferring a circuit pattern from a reference mask onto the substrate by exposure to an interactive energy field or source when the chamber is assessed to contain gas of sufficiently high purity for high quality device production.
A method of measuring purity information relating to reduced pressure gas contained at least at moderate vacuum levels in a closed space, said method comprising:
- generating ultrasonic waves in the reduced pressure gas contained in the closed space;
- measuring the value of sonic velocity in the reduced pressure gas in the closed space;
- and
- determining purity information relating to the reduced pressure gas in the closed space on the basis of the measured value.
A chamber unit comprising:
- a vacuum chamber having a closed space for containing reduced pressure gas at least moderate vacuum levels;
- means for generating ultrasonic waves in the reduced pressure gas contained in said closed space;
- sonic velocity measuring means for measuring the value of sonic velocity in the reduced pressure gas in said chamber;
- and
- determination means for determining purity information relating to the reduced pressure gas in said chamber, on the basis of the value measured by said sonic velocity measurement means.
An exposure apparatus comprising:
- a vacuum chamber containing a substrate in a reduced pressure gaseous ambience at least at moderate vacuum levels;
- exposing means for exposing the substrate to an interactive energy field or source;
- means for generating ultrasonic waves in the reduced pressure gas contained in said chamber;
- sonic velocity measuring means for measuring the value of sonic velocity in the reduced pressure gas in said chamber;
- and
- determination means for determining purity information relating to the reduced pressure gas in said chamber, on the basis of the value measured by said sonic velocity measurement means.
A device production method comprising the steps of:
- containing a substrate in a reduced pressure gaseous ambience at least moderate vacuum levels in an airtight chamber;
- generating ultrasonic waves in the reduced pressure gas contained in the chamber;
- measuring the value sonic velocity in the reduced pressure gas in the chamber;
- determining purity information relating to the reduced pressure gas in the chamber, on the basis of the measured value of the sonic velocity;
- and
- transferring a circuit pattern from a reference mask onto the substrate by exposure.
Dependencies are inferred from the claim text.