JPS63274131A - Exposure device - Google Patents

Abstract

PURPOSE:To enable the title device to recognize the deterioration level of a pellicle for informing an operator of the life of pellicle by a method wherein the transmissivity of light passing through the pellicle is automatically measured. CONSTITUTION:When a command is given to load a photomask 1 with a pellicle, a carriage 9 is operated before setting the mask 1 to a mask stage 2 to irradiate projecting light flux 8 from an illuminating optical system 6. This light flux 8 is focussed on a photodetector 10 for measuring light intensity set on the level similar to that between wafers. The light intensity without pellicle is memorized as A. A window 14 for measuring light intensity is made on the position corresponding to the photodetector 10 on the mask 1 to make, the light passing through the window 14 focus on the photodetector 10. The intensity when passing through the pellicle is memorized as B. This value of B/A is indicated as the transmissivity T of pellicle. At this time, the transmissivity T is previously set up to inform an operator of the life of pellicle by alarming when T falls below the set up value Tc.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an exposure apparatus, and particularly to an exposure apparatus used in semiconductor manufacturing.

(Prior Art) Conventionally, the device shown in FIG. 3 is known as this type of device.

In the figure, 1 is a semiconductor exposure substrate with a dustproof device (hereinafter referred to as
It is called a photomask with a pellicle or simply a mask. )
, 2 is a mask stage, 3 is a mask loader, 4 is a wafer, 5 is a wafer stage, 6 is an illumination optical system, 7 is a projection optical system, 8 is a projection exposure light beam, and 9 is a scanning carriage.

Next, the operation will be explained.

A photomask 1 with a pellicle is loaded onto a mask stage 2 by a mask loader 3. Next, the wafer 4 is set on the wafer stage 5, and after the alignment of the mask and the wafer is completed, the illumination optical system 6 emits a light beam 8.

The light beam 8 passes through the mask 1 and the projection optical system 7, and forms an image on the wafer 4. In the conventional apparatus, the scanning carriage 9 scans at this time, so that the light beam 8 can illuminate the entire surface of the mask 1 and the wafer 4.

[Problem that the invention seeks to solve]

However, in the conventional exposure apparatus, the set photomask 1 with a pellicle has no choice but to be used without performing any inspection.

However, it is known that the material of pellicles deteriorates due to the ultraviolet rays irradiated by exposure equipment. Therefore, users must separately record the usage time of each mask and use that to estimate the lifespan of the pellicle. Coupled with the fairly frequent replacement, the problem was that it was difficult to know whether the pellicle had actually deteriorated.

This invention was made to solve the above-mentioned problems.By automatically measuring the transmittance of light passing through the pellicle, it is possible to determine the degree of deterioration of the pellicle and to report the lifespan of the pellicle. The aim is to obtain a device that makes it possible.

[Means for solving problems]

Therefore, in the exposure apparatus according to the present invention, the above object is achieved by providing a light receiving element for measuring light intensity at the exposure focal position near the wafer stage.

Further, another exposure apparatus according to the present invention provides a portion (hereinafter referred to as a "window") where there is no light-shielding material at a predetermined location for light intensity measurement.
That's what it means. ) is used.

[Effect]

With the above configuration, the exposure apparatus according to the present invention has the following features:
The intensity of the light emitted from the illumination optical system is measured by the light receiving element before and after loading the mask, and the light intensity without the mask is compared with the light intensity with the mask (i.e., via the pellicle) to determine the transmission through the pellicle. Measure the rate.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
In the figure, 10 is a light receiving element for measuring light intensity. FIG. 2 is a detailed view of the photomask 1 with a pellicle depicted in FIG. 1. In FIG. This is the "window" part for measuring light intensity.

Next, the operation will be explained. When a command to load the photomask 1 with a pellicle is issued, the carriage 9 moves to the position shown in FIG. 1-2 before setting the mask 1 on the mask stage 2, and the illumination optical system 6 irradiates the projection light beam 8. do. This light beam is focused on a light receiving element 10 for measuring light intensity, which is set at the same height as the surface of the square. The light intensity at this time is measured by the same light receiving element 10, and the light intensity without the pellicle is stored as A. Next, the mask 1 is set on the mask stage 2, and then, as shown in FIGS. 1 to 3, the light beam 8 is irradiated again. This luminous flux 8
First, the light is focused on the mask 1, but since the "window" 14 for measuring light intensity shown in FIG. Tie. The light intensity at this time is stored as B when it passes through the pellicle.

Ru.

At this time, the transmittance T is set in advance, and when it falls below the set value Tc, an alarm is displayed to notify the user of the lifespan of the pellicle.

It goes without saying that the apparatus is configured so that this transmittance measurement operation is performed not only when loading the mask, but also automatically after the number of exposure operations set by the user is completed.

According to an embodiment of the present invention, the life of the pellicle can be determined by measuring the intensity of light emitted from the illumination optical system with the light receiving element before and after loading the mask, and comparing the light intensities. Mask management becomes easier, and
This has the effect of preventing a decrease in yield.

〔Effect of the invention〕

As explained above, according to the present invention, since the transmittance of the pellicle is configured to be measured, it is possible to know the lifespan of the pellicle in use, which facilitates mask management. It also has the effect of being able to prevent a decrease in yield.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of an exposure apparatus according to an embodiment of the present invention, in which (a) shows a state in which a mask is set on a mask stage, (b) shows a state in which a carriage is moved, and (c) shows a state in which a mask is set on a mask stage. It is shown set on a stage, FIG. 2 is an example of a photomask used in this exposure apparatus, and FIG. 3 is a side sectional view showing a conventional exposure apparatus. In the figure, 1 is a photomask with verital, 2 is a mask stage, 3 is a mask loader, 4 is a wafer, 5 is a wafer stage, 6 is an illumination optical system, 7 is a projection optical system, 8 is a projection light beam, and 9 is for scanning The carriage, 10 is a light receiving element for measuring light intensity, and 14 is a "window" portion for measuring light intensity. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (2)

[Claims] (1) An exposure apparatus characterized in that when loading an exposure substrate for semiconductor manufacturing with a dust prevention device, the transmittance of the exposure substrate dust prevention device can be determined from the difference in transmitted energy before and after loading. (2) The exposure apparatus according to claim 1, characterized in that, for transmittance measurement, an exposure substrate is used in which a portion without a light-shielding material is provided at a predetermined location.