JPS63107177A - Device for detecting wavelength of laser beam - Google Patents

Abstract

PURPOSE:To make alignment unnecessary and to enable a title device to be small-sized by providing an optical fiber having one end thereof inserted into the light path of a laser beam and taking out part of the laser beam, and a monitor means for forming an interference fringe of the laser beam guided by the optical fiber and detecting the wavelength of the laser beam from this interference fringe. CONSTITUTION:An optical fiber 17 is inserted into the light path of a laser beam 3 through a light collecting section 15, and the other end is connected to a monitor etalon 19. In the light collecting section 15, a head portion 25 is provided on a magnet stand 21 through a rod 23, and the optical fiber 17 is passing through the rod 23 with its leading end 27 being exposed to the head portion 25. The monitor etalon 19 has a projector portion 29, an etalon 31, a line detector 33 and a power monitor detector 35; the projector portion 29 projects a laser beam to the etalon 31, the etalon 31 transmits only the laser beam of a specified wavelength, and the line detector 33 generates an interference fringe of the laser beam to detect the line width and wavelength of the laser beam.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wavelength detection device for detecting the wavelength of laser light.

(Prior Art) As a conventional laser beam wavelength detection device, there is one shown in FIG. 7, for example. In the figure, excimer laser 1
generates laser light 3. The beam splitter 5 is placed in the optical path of the laser beam 3, and transmits a portion of the laser beam and reflects a portion of the laser beam.

Lens 7 guides the laser beam reflected by beam splitter 5 to optical fiber mount 9. The fiber optic mount 9 is connected to the monitor etalon 11 by an optical fiber 13.

The light reflected by the beam splitter 5 passes through a lens 7° and an optical fiber mount 9. The laser beam is sent to the monitor etalon 11 via the optical fiber 13, and the interference fringes of the laser beam are detected in the monitor etalon 11, and as a result, the line width and wavelength of the laser beam are detected.

[Problem that the invention seeks to solve]

However, in such a wavelength detection device, the beam splitter 5. Since the lens 7 and the like were used, there were problems in that alignment was difficult and the apparatus became large.

The present invention has been made in view of these problems, and it is an object of the present invention to provide a laser beam wavelength detection device that does not require alignment and can be miniaturized.

[Means for solving problems]

In order to achieve the above object, the present invention includes an optical fiber whose end is inserted into the optical path of a laser beam and takes out a part of the laser beam, and an optical fiber that forms interference fringes of the laser beam guided by the optical fiber and eliminates this interference. The apparatus is characterized by comprising a monitor means for detecting the wavelength of the laser beam from the stripes.

[Effect]

Since the laser beam is directly guided to the monitoring means by the optical fiber, there is no need to perform alignment of the device, and the device can be made smaller.

〔Example〕

Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 1 shows the configuration of a wavelength detection device according to an embodiment of the present invention. Excimer laser 1 generates laser light 3. An optical fiber 17 is inserted into the optical path of the laser beam 3 via a condenser 15, and the other end of this optical fiber is connected to a monitor etalon 19.

FIG. 2 is a view of the condensing unit 15 viewed from the direction AA, and a head 25 is provided on the magnetic stand 21 via a rod 23. An optical fiber 17 passes through the rod 23, and the tip 27 of the optical fiber 17 is exposed to the head 25.

FIG. 3 is a configuration diagram of the monitor etalon 19. As shown in the figure, the monitor etalon 19 has a projection section 29 provided at the end of the optical fiber. Etalon 31. Line detector 33. It has a power monitor detector 35. The projection unit 29 projects the laser beam sent through the optical fiber 17 onto the etalon 31. The etalon 31 transmits only laser light of a specific wavelength. The line detector 33 generates interference fringes of the laser beam and detects the line width and wavelength of the laser beam.

In FIG. 1, the laser beam 3 that has been deactivated by the excimer laser 1 is collected at a condensing section 15. The laser beam is sent through an optical fiber 17 to a monitor etalon 19, where the line width and wavelength of the laser beam are detected.

In this way, in this embodiment, one end of the optical fiber 17 is inserted directly into the optical path of the laser beam, and the laser beam sent through this optical fiber 17 is detected. Lens 7 etc. are not required. This eliminates the need for alignment and allows the device itself to be downsized. Furthermore, power monitor detector 35
The power of the laser beam can be determined by

FIG. 4 is a block diagram of the excimer laser stepper. As shown in the same figure, this excimer laser stepper beam has 3 amices and an etalon 39. Laser head 41. Front mirror 432 reflector 45° ink grater 4 f2 anti 1)
18fl 49, condenser lens 51. Reticle 5
3. Projection lens 55. Uef? Consists of 57.

The etalon 39 transmits only laser light of a specific wavelength. The laser head 41 performs life and death of laser light. The integrator 47 converts the laser light into multi-source light. Reticle 5
3 has a button to be formed on the wafer 57, and the light transmitted through the reticle 53 is directed to the wafer 5 through the projection lens 55.
7 and a predetermined pattern is formed on the wafer 57.

When using the wavelength detection device according to the present invention in such an excimer laser stepper, there are
, between the integrator 47 and the reflecting mirror 49, between the reflecting mirror 49 and the condenser lens 51, between the condensing lens 51 and the reticle 53, above the reticle 53, etc. Can be done.

FIG. 5 illustrates a case where the light condensing section 15 is arranged near the reticle 53, and the light condensing section 15 is screwed into the reticle holder 59 with a screw (not shown). The laser beam 61 irradiated from the condenser lens 51 is directed toward the reticle 5.
3, the laser beam can be guided to the monitor etalon 19 even if the condenser 15 is placed in such a position.

In FIG. 6, a beam splitter 63 is positioned between a reticle 53 and a condenser lens 51, a portion of the laser beam is reflected by the beam splitter 65, and the wavelength of the reflected laser beam is detected. That is, the reticle holder 59
The condensing section 15 is fixed via a rod 67 to the condensing section 15, and the laser beam 65 reflected by the beam splitter 63 is transmitted to the condensing section 15.
This laser light 65 is sent to the monitor etalon 19 via the optical fiber 17 to detect the wavelength of the laser light.

As described above, by using the wavelength detection device according to this embodiment, wavelength detection can be performed at various positions of the excimer laser step.

[Effects of the Invention] As described in detail above, according to the present invention, there is no need to perform alignment, and the device can be downsized.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a laser beam wavelength detection device according to an embodiment of the present invention, FIG. 2 is a view taken along arrow A-A of a condensing section, and FIG. 3 is an internal configuration diagram of a monitor etalon. Figure 4 is a configuration diagram of the excimer laser stepper, Figure 5 is an explanatory diagram when the condenser is attached to the reticle, Figure 6 is an explanatory diagram when wavelength detection is performed using a beam splitter, and Figure 7 is an explanatory diagram when wavelength detection is performed using a beam splitter. FIG. 1 is a schematic configuration diagram of a conventional wavelength detection device. 15... Concentrating section, 17... Optical fiber, 19...
monitor etalon. Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] An optical fiber whose end is inserted into the optical path of a laser beam and takes out a part of the laser beam, and an interference fringe of the laser beam guided by the optical fiber, and from this interference fringe, the laser beam is extracted. What is claimed is: 1. A wavelength detection device for laser light, comprising: monitoring means for detecting the wavelength of a laser beam.