JPS639170A - Gas laser device - Google Patents

Abstract

PURPOSE:To lower the out-of-operation rate of a system incorporating a laser device due to laser device outage by a method wherein a laser head, containing the two windows at both ends of an optical axis and capable of discharge- triggered gas excitation, is made movable, relative to a fixed laser resonator, in the direction vertical to the optical axis. CONSTITUTION:A laser head 3, containing windows 3a and 3b at both ends of an optical axis and capable of discharge-triggered gas excitation, is designed to be movable, relative to a fixed laser resonator 2, in the direction vertical to the optical axis. For example, excitation in a laser medium initiated by a laser head 3 travels through windows 3a and 3b at both ends of the optical axis of the laser head 3, undergoes resonance between two mirrors 6 and 7 of a laser resonator 2, and is taken out as a laser beam. Two or more laser heads 3, completely identical with each other, are installed on a platform 15 capable of movement relative to a housing 4, the platform 15 is caused to turn or slide for one of the laser heads 3 to be set on the optical axis or removed therefrom.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a gas laser device such as an excimer laser.

BACKGROUND OF THE INVENTION In devices that use a conventional laser as a light source, such as an IPII excimer laser stepper, it is very important to maintain a high operating rate of the laser.

On the other hand, in the past, when the laser must be stopped due to maintenance or failure of the laser, attempts have been made to improve maintainability and rationality to shorten the stoppage time.

If possible, a replacement laser device is prepared and light is supplied from this replacement laser device during the downtime.

Problems to be Solved by the Invention In gas laser devices such as excimer lasers, which have low reliability for long-term operation and require frequent maintenance, stopping the laser for maintenance or repair is an important problem.

The downtime varies depending on the situation, and even if repairability is improved, a malfunction may require a long outage.

In addition, when using a replacement laser device, in conventional laser devices, the laser head and laser resonator, which generate the laser medium by electric discharge, are integrally supported, so each time the laser device is replaced, In addition to requiring a long time to adjust the optical system with a precision optical system, the laser device for replacement must be moved to another location without moving the stopped laser.
If it does, it will not be in the optimal position and may impair the performance of the entire device.

Means and Effects for Solving the Problems The present invention has been made in view of the above-mentioned problems, and when the laser head is stopped, a replacement laser head can be quickly replaced and operation can be continued, and the laser head can be continuously operated. The object of the present invention is to provide a gas laser device that can significantly suppress a decrease in operating rate due to the stoppage of the laser device of the device using the device, and that does not impair the performance of the entire device due to replacement of the laser device. , its configuration includes windows at both ends in the optical axis direction with respect to a fixed laser resonator, and the laser head that excites the gas by discharge is movable in a direction perpendicular to the optical axis. As a result, a plurality of laser heads can be replaced and used for a laser resonator.

Example Embodiments of the present invention will be described based on the drawings.

Fig. 1 shows an excimer laser stepper showing an example of the use of a gas laser device. In the figure, 1 is an excimer laser device that generates excimer laser light, and this excimer laser device 1 is a laser that determines the optical axis of the laser light. A resonator 2 and a laser head (discharge tube) 3 that generates a laser medium by electric discharge are independently supported by a machine frame 4.

The laser head 3 is detachably attached to the machine frame 4 in a direction perpendicular to the optical axis.

The laser resonator 2ri consists of a solid etalon 5 located below the laser head 3, a rear mirror 6, and a front mirror 7 located above. It passes through windows 3a and 3b at both ends, resonates between both mirrors 6.7 of the laser resonator 2, and is extracted as a laser beam.

and the laser beam rt mirror 6, the integrator 9,
The image is projected onto the Uni-No 14 via a mirror 10, a condenser lens 11, a reticle 12, and a projection lens 13.

The relationship between the laser head 3 and the machine frame 4 is as shown in FIGS. 2 and 3. At least two identical laser heads 3 are prepared, and these are attached to the machine frame 4. A movable stand +5. +5α, placed on 15b, this table 15.158. +51! By rotating or sliding the laser head 1, each laser head 3 can be set on the optical axis or taken out. The above-mentioned stands 15.15α and 15h are insulated against vibrations and the like. Although not shown, accessory devices such as a power source and a gas circulation device are connected to both laser heads 3 in a freely switchable manner.

In the above configuration, when it is necessary to stop the laser head 3 set on the optical axis, it is necessary to stop the laser head 3 set on the optical axis. +5cL
, +5h to move the laser head 3 on this optical axis to the outside of the machine frame 4, and move the laser head 3 on the optical axis to the outside of the machine frame 4.
is set on the optical axis and the laser head 3 is operated.

As a result, operation can be resumed after a short downtime.

In the above embodiment, two laser heads 3 are prepared for one laser device, and one of them is used as a spare. However, for a plurality of laser devices, one spare laser head is used. You can do it like this. Further, the gas laser device is not limited to a vertical type, but may be a horizontal type.

Effects of the Invention According to the present invention, when the laser head 3 in operation breaks down and is stopped, it is possible to immediately replace it with another laser head 3 and continue the operation, and the laser device can be used. It is possible to significantly suppress a decrease in the operating rate due to the stoppage of a device, for example, a laser device of a working machine such as an excimer laser stepper. Further, according to the present invention, since only the laser head 3 is replaced, the laser resonator 2 does not change even when the laser device is stopped and restarted, and therefore -C
There is no need to adjust the optical system, and the same laser light as before the laser head 3 is replaced can be supplied without impairing the performance of the entire device.

[Brief explanation of drawings]

Fig. 1 is a schematic structural explanatory diagram of an excimer laser stepper using a gas laser device according to the present invention, Figs.
The figure is a perspective view showing an embodiment of a support section of a laser head. 2 is a laser resonator, 3 is a laser head, and 3i. 3h is window.

Claims (1)

[Claims] A laser head 3 that includes windows 3a and 3b at both ends in the optical axis direction and that excites gas by discharge is movable in a direction perpendicular to the optical axis with respect to a fixed laser resonator 2. gas laser equipment.