JPS6312343A - Ultraviolet laser monitor - Google Patents

Abstract

PURPOSE:To precisely monitor the position and shape of laser light with an inexpensive mechanism by arranging a transparent glass sheet emitting fluorescence by the radiation of UV laser on the outside of a laser light outputting window, and providing an image pickup device capable of simultaneously catching the luminous image and the peripheral inclusions. CONSTITUTION:UV laser light 12 is passed through a reactor 2 in parallel with the surface of a sample 5 from an input window 9 in the laser CVD (chemical vapor deposition) device, and photochemical reaction is carried out on the plane of the sample 5. The transparent glass sheet 13 emitting fluorescence by the radiation of the UV laser light 12 is arranged on the outside of the output window 10 for introducing the laser light 12 to the outside of the reactor 2. Besides, the image pickup device 15 is arranged to catch the luminous image and the peripheral inclusions in the visual field. Since the laser light 12, the sample 5, and the peripheral inclusions can be observed by the same image surface of the monitor device 20 in this way, a change in the setting of a process parameter is facilitated, and the exposure to harmful UV rays can be prevented, since the observation is done by the monitor device 20.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an ultraviolet laser monitor for an apparatus that causes a photochemical reaction in an ultraviolet laser light reactor.

[Prior Art] In recent years, ultraviolet laser light with a wavelength of 183 to 350 nm, such as excimer laser, has begun to be widely used in research on semiconductor manufacturing equipment and its processes, but when the wavelength is 380 nm or less, direct visual observation is impossible. This makes it difficult to set and confirm process conditions.

As a method for easily observing the irradiation state of such ultraviolet laser light, there is a method of observing the emission using a fluorescent screen. Further, as means for visualizing ultraviolet images, there are an ultraviolet vidicon, a microchannel plate (MCP) sensitive to the ultraviolet region, and a highly sensitive ultraviolet image intensifier (II). For measuring the amount of ultraviolet light (energy), there are ultraviolet light meters and ultraviolet laser light power meters.

However, although the method of using the fluorescent screen is easy, there is a risk of exposure to harmful ultraviolet rays due to reflection and scattering of ultraviolet rays, which poses a safety problem. Furthermore, it is difficult to measure delicate beam shapes and intensity distributions.

On the other hand, the ultraviolet vidicon, MCP, and II all have high sensitivity and are poor for ordinary video use.
Powerful spot light such as a laser beam causes halation and burn-in on the imaging surface, which poses practical problems. Furthermore, if the light intensity is attenuated to an appropriate level, when observing the irradiation position of the ultraviolet laser beam in relation to surrounding inclusions such as a sample, the surrounding inclusions will no longer be visible, and strong illumination will be required in that area. Furthermore, they are also very expensive. In addition, when using a laser power meter, the light receiving part is generally large, so the beam position,
Not suitable for measuring shapes.

[Problems to be Solved by the Invention] An object of the present invention is to capture the emission image of ultraviolet laser light without the risk of exposure to harmful ultraviolet rays by using a transparent glass plate that emits fluorescence when exposed to ultraviolet rays, and to It simultaneously captures images of peripheral inclusions in the reactor whose positional relationship with the light irradiation position must be observed, displays them in real time, and accurately monitors the position and shape of the laser beam using a low-cost mechanism. The goal is to obtain an ultraviolet laser monitor that can be used for monitoring.

゛[Means for Solving the Problems] In order to achieve the above object, the ultraviolet laser monitor of the present invention provides an ultraviolet laser monitor that monitors the outside of the output window of the laser beam in the reactor through which the ultraviolet laser beam is caused to cause a photochemical reaction. To,
An imaging device that captures an image of the emitted light through a transparent glass plate that emits fluorescence when irradiated with an ultraviolet laser, and also captures images of peripheral inclusions in the reactor whose positional relationship with the irradiation position of the ultraviolet laser beam should be observed. and connect it to a monitoring device.

[Function] According to the ultraviolet laser monitor having the above configuration, the glass plate that emits fluorescence by irradiation with the ultraviolet laser is removed,
The positional relationship between peripheral inclusions such as a sample in the reactor and the laser beam, as well as the cross-sectional shape of the laser beam, can be determined using a single imaging device.
The images are displayed on a single monitor device, so they can be monitored accurately without the risk of exposure to harmful ultraviolet radiation.

[Example] FIG. 1 illustrates the configuration of a laser CVD (chemical vapor deposition) apparatus equipped with four ultraviolet laser monitors according to the present invention.
A Y stage 3 is provided, and a sample 5 is placed on a support base 4 provided thereon.

In addition, the wall of the reactor 2 is provided with an exhaust port 8 communicating with the vacuum system δ and a lower part 8 for introducing the reaction gas into the reactor 2, as well as an input window 9 and an output window IO for laser light. The ultraviolet laser beam 12 from a laser device (not shown) is passed through the input window 9 parallel to the surface of the sample 5 placed in the reactor 2 to cause a photochemical reaction on the sample surface. . The output window 10 is for guiding the laser beam 12 that has passed through the surface of the sample 5 to the outside of the reactor 2. In order to visualize the invisible ultraviolet laser beam that has passed through the output window 10, an output window 10 is provided outside the output window 10. is ultraviolet ray Q-
A transparent glass plate 13 that emits fluorescent light when irradiated with laser light is disposed, and an imaging device 15 that captures an image emitted by the ultraviolet laser is disposed through the transparent glass plate 13. In order to observe the irradiation position of the ultraviolet laser beam 12 in relation to the peripheral inclusions such as the sample 5 in the reactor 2, the imaging device 15 is arranged so that the peripheral inclusions are also included in the field of view. This is what I did. In addition, in the figure, 17 indicates a UV cut filter to be attached as necessary, and 18 indicates a close-up lens.

As the imaging device 15, one equipped with a semiconductor imaging device, such as a COD or MO3 type 3 camera, is generally used, but the invention is not necessarily limited to these.

The imaging device 15 is connected to a video monitor device 20 .

According to the ultraviolet laser monitor having such a configuration, the positional relationship between the sample surface in the reactor 2 and the laser beam 12 and the cross-sectional shape of the laser beam can be observed through one imaging device 15 through the transparent glass plate 13. 0 output that can be observed on one video monitor device 20; 21 is an emission image of the laser beam displayed on the video monitor device 20; 2;
2 is an image of the sample as well.

In addition, a color type imaging device 15 such as the COD camera is used, and a He-Me red (6328A) laser beam light is superimposed as a reference light on the center of the ultraviolet laser light 12, and both direct visual observation and video observation are performed. Monitor device 2
If each laser can be observed simultaneously even on 0, it will be more convenient.

In addition, in order to sharpen the focus of the luminescent image on the transparent glass plate 13 and the plane image of the sample, the close-up lens 18 of the imaging device 15
It would be desirable to be able to easily mount the lens, or to be able to quickly and easily exchange close-up lenses with different focal lengths.

° Furthermore, shooting f! In the device 15, if one lens is used to focus the luminescent image on the transparent glass plate 13, the image of the sample, etc. inside the reactor 2, which is simultaneously imaged, will be blurred to some extent. By focusing on the sample shape and marking the sample shape on the transparent glass plate 13 or the screen of the video monitor device 20, the sample surface position can be made clear.

[Effects of irradiation] According to the ultraviolet laser monitor of the present invention detailed above, since the (+) laser beam and peripheral inclusions can be observed on the same image plane, it is easy to change the settings of process parameters, and
Improves reproducibility and operability.

(2) Arranging an imaging device that captures the luminescent image through a transparent glass plate that emits fluorescence when irradiated with an ultraviolet laser;
Since it can be observed using a monitor device connected to it, there is no risk of exposure to harmful ultraviolet rays.

(3) There is no need to use a high-sensitivity imaging device, and as a result, there is no need to use a high-sensitivity imaging device, so there is no possibility of halation caused by strong spot light or burn-in on the imaging surface, and there is no need to use ultraviolet rays on the imaging device. It has a long lifespan as there is no incidence of

(4) Without using particularly expensive equipment, laser
The position and shape of light can be monitored with high precision and low cost.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a laser CVD apparatus equipped with an ultraviolet laser monitor according to the present invention. 2. Reactor, 8. Input window, 10. Output window, 12. Ultraviolet laser light, 13.
・Transparent glass plate, 15φ・Imaging device, 20・Romonitor device.

Claims (1)

[Claims] 1. A laser monitor for an apparatus in which the laser beam is passed through a reactor having an input/output window for the ultraviolet laser beam to cause a photochemical reaction within the reactor, and the ultraviolet laser beam is provided outside the output window. An imaging device is installed to capture the emitted light image through a transparent glass plate that emits fluorescence when irradiated with the ultraviolet laser beam, and to capture images of peripheral inclusions in the reactor whose positional relationship with the irradiation position of the ultraviolet laser beam should be observed. An ultraviolet laser monitor characterized in that the ultraviolet laser monitor is connected to a monitoring device.