JPH0542806B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exposure apparatus applied to a semiconductor printing apparatus for transferring a mask pattern onto a wafer.

Various types of semiconductor printing equipment are used to manufacture semiconductor devices such as ICs and LSIs. This semiconductor printing apparatus is equipped with an exposure light source unique to the apparatus, and is configured to use light emitted from the exposure light source to print a circuit pattern drawn on a mask or reticle onto a wafer coated with a photoresistor. .

Furthermore, as is well known, semiconductor printing equipment repeats various work steps such as loading the wafer to the exposure stage, aligning the relative position of the mask and wafer, exposing the wafer, and transporting the wafer from the exposure stage. Then, wafers with printed patterns are mass-produced.

In other words, the exposure process is only one part of the total process required to print circuit patterns onto a wafer. However, in current semiconductor printing equipment, each device is equipped with an exposure light source, and this exposure light source is always turned on to stabilize the exposure light, and as mentioned above, the shutter is turned off during processes other than the exposure process such as position alignment. By using a light shielding member such as the above, exposure light was prevented from reaching the wafer on the exposure stage.

Therefore, the equipment of the printing apparatus itself becomes large-scale, and it is undesirable that it occupies a large space, especially considering that in general semiconductor manufacturing factories, a plurality of printing apparatuses are used side by side. In addition to this, the exposure light source is turned on even during non-required exposure steps, resulting in a large waste of energy.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide an exposure apparatus that allows a semiconductor printing apparatus to be made lighter and allows effective use of exposure light.

According to the present invention, in order to achieve the above-mentioned object, exposure light emitted from a common exposure light source is directed to a plurality of exposure stages. If the exposure light source is shared by a plurality of exposure stages in this way, it is not necessary to provide a separate exposure light source for each printing apparatus, which helps to reduce the weight of the printing apparatus. Here, the case where one exposure stage is provided in one printing apparatus is not limited, and the case in which one printing apparatus is provided with a plurality of exposure stages is also conceivable. In this case as well, the exposure light source is shared by a plurality of exposure stages.

Furthermore, if the exposure light is directed to a plurality of exposure stages, the overall exposure process time for one exposure light source will increase, so it is also possible to significantly reduce the loss of exposure energy. Furthermore, in recent years, there has been a trend toward centralized control of printing equipment in semiconductor manufacturing factories, and it is clear that central control of printing equipment becomes easier by sharing an exposure light source.

Further according to a preferred feature of the invention, the common exposure light source continuously oscillates a laser. Since lasers are superior to mercury lamps in terms of directivity of the light flux, it is sufficient to arrange simple optical elements to guide the light from the exposure light source to the exposure stage.

According to a further preferred feature of the invention, the common exposure light source pulses the laser. As described above, it is sufficient to simply arrange a simple optical element to guide light from the exposure light source to the exposure stage. In addition, since the laser is oscillated in a pulsed manner, loss of exposure energy can be completely eliminated by adjusting the timing of the pulse oscillation to match the exposure timing of each exposure stage.

Further in accordance with a preferred feature of the invention, the exposure light is selectively directed to coincide with the exposure timing of each of the exposure stages. If it becomes necessary to stop the printing operation of one of the printing apparatuses due to an unexpected accident or the like, the preset exposure schedule must be suddenly changed. In such a case, if the exposure light can be controlled so as to be guided selectively to the desired exposure stage, no problem will arise.

Next, preferred embodiments of the present invention will be described. In FIG. 1, reference numbers 6, 7, 8, and 9 indicate exposure stages, and reference number 1 indicates an exposure light source common to these exposure stages 6, 7, 8, and 9.
The light emitted from the exposure light source 1 is passed through optical elements 2, 3, 4, 5 such as plane mirrors to exposure stages 6, 7,
8 and 9 respectively.

The last optical element 5 among the illustrated optical elements
The other optical elements 2, 3, and 4 can be alternately moved between a position for directing the exposure light to the exposure stages 6, 7, and 8, and a position for passing the exposure light.

Preferably, the movement of the optical elements 2, 3, 4 is controlled by the control device 10 so as to guide the light to a desired exposure stage 6, 7, 8, 9.

In this embodiment, the optical element 5 placed at the rear end is fixed at a position where it directs the light to the stage 9, but it may be movable like the other optical elements 2, 3, and 4. it is obvious.

As the exposure light source 1, a mercury lamp, a laser, etc. can be considered. The luminous flux from a mercury lamp is inferior in terms of directivity, so if the optical path is lengthened, the luminous flux will spread out. Therefore, the exposure light source 1 and the exposure stage 6,
It is necessary to arrange an appropriate optical system between the elements 7, 8, and 9. In this respect, in the case of a laser, an optical system with a simple configuration is sufficient because the directionality of the light beam is good.

Furthermore, by selecting the oscillation state of the laser, the effect of the present invention of reducing exposure energy loss becomes even more remarkable. In recent years, excimer lasers have become known as pulsed oscillation lasers. In this case, if the pulse oscillation timing is controlled in accordance with the exposure timing of each exposure stage, no exposure energy is wasted even if the exposure light source 1 is kept operating all the time. Excimer lasers have a large output, so
For example, in the case of a step-and-repeat aligner (so-called stepper), the exposure may be 1 shot or 1, depending on the type of photoresist and various conditions.
~A few pulses are sufficient and the exposure time is shortened.

Therefore, the time required for exposure per device is short, and it is possible to expose wafers located on a large number of exposure stages using a common light source.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the present invention. 1... Exposure light source, 2, 3, 4, 5... Optical element, 6, 7, 8, 9... Exposure stage, 10...
Control device.

Claims (1)

[Claims] 1 a plurality of exposure stages on which each wafer is placed; a light source common to the plurality of exposure stages;
an optical system that directs light from the common light source to each exposure stage, wherein the optical system includes a movable mirror that switches the optical path of the light from the common light source, and the movable mirror directs the light from the common light source. An exposure apparatus characterized in that it is directed to each exposure stage sequentially.