Laser apparatus and method for controlling the same
AssigneeNikon Corporation
InventorTsuyoshi Toki
Life of this patent
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Abstract
A laser apparatus includes a laser element that emits the laser beam. A detector detects the laser beam emitted from the laser element. A controller controls the laser element such that the laser beam is oscillated subject to multiple conditions, such as the emission frequency and the energy of the laser beam, when the laser element is in a ready state, based on the detection results. In the ready state, the laser beam is not emitted from the apparatus onto a subject. Closely monitoring the oscillated beam in the ready state allows the precise beam desired to be emitted in an operational mode. The apparatus is useful for fabricating semiconductor devices.
Claims16
A laser apparatus which supplies a laser beam to an exposure device, comprising:
- a laser element that emits pulses of the laser beam, the laser element including a laser resonator;
- a detector that detects the laser beam emitted from the laser beam body;
- and
- a controller that controls the laser element to emit the laser beam under a plurality of emission conditions in a ready state, and forms plural pieces of control data corresponding to the respective emission conditions based on detection results of the detector, the plurality of emission conditions being different from each other in at least one of an energy of the laser beam and an emission period of the laser beam,
- wherein the controller selects one of the plural pieces of control data for controlling the laser element when the laser beam emitted from the laser element is supplied to the exposure device.
A method of controlling a laser apparatus that supplies a laser beam to an exposure device, comprising:
- emitting pulses of the laser beam under a plurality of emission conditions during a ready state in which the laser beam is not directed to the exposure device, the plurality of emission conditions being different from each other in at least one of an energy of the laser beam and an emission period of the laser beam;
- detecting the emitted laser beam in the ready state;
- forming, on the basis of information obtained by detecting the laser beam in the ready state, plural pieces of control data corresponding to the respective emission conditions;
- selecting one of the plural pieces of control data;
- and
- supplying the laser beam to the exposure device while controlling an emission of the laser beam of the laser apparatus based on the selected control data.
A laser apparatus that emits a laser beam to an external device, comprising:
- a laser element that emits the laser beam, the laser element including a laser resonator;
- and
- a laser controller, connected to the laser element and the external device, that receives information from the external device and controls the emission of the laser beam from the laser element, wherein the controller determines an emission condition of the laser beam based on the information during a ready state, in which the external device does not use the laser beam, and
- wherein the information includes an emission condition of the laser beam used in an operation which is performed by the external device after the ready state.
Dependencies are inferred from the claim text.