JPS63204723A - Reduction stepper - Google Patents

Abstract

PURPOSE:To eliminate any out of focus in case of exposure due to dirt on a substrate holding base by means of cleaning the base every time after finishing the exposure of semiconductor substrate. CONSTITUTION:A substrate holding base 1 with a semiconductor substrate removed therefrom after exposure is shifted to a cleaning vessel 8 by a carrier arm 5 and a carrier belt 6 comprising a substrate holding mechanism. Within the cleaming vessel 8, the rotating substrate holding base 1 held by a movable arm 11 is cleaned up by pure water nozzles 13 and a cleaning brush 12 comprising a cleaning mechanism to be dried up by the movable arm 11 turning at high speed. The cleaned up substrate holding base 1 is shifted to a positioning plate 9 by another carrier belt 7. Finally, the cleaned up and positioned substrate holder 1A is shifted to X-Y stage again to hold another semiconductor substrate repeatedly.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a reduction projection exposure apparatus.

[Conventional technology]

With conventional reduction projection exposure equipment, when a semiconductor substrate is held, dust or the like gets caught between the semiconductor substrate and the holder, resulting in a local out-of-focus phenomenon when exposing that part. However, in order to avoid this, the substrate holder is devised to reduce the contact area with the semiconductor substrate as much as possible.

[Problem that the invention seeks to solve]

However, when using the above-mentioned conventional substrate holder, the influence of dust on the back side of the semiconductor substrate is reduced in probability, but when the semiconductor substrate is held by the substrate holder, dust may be caught in the substrate holder, resulting in a localized focus. The decrease that causes the discrepancy will not disappear.

If this dust is peeled off from the back surface of the semiconductor substrate and remains on the substrate holder, there is a problem in that it affects the defocusing of the next semiconductor substrate and reduces the yield rate. In addition, even if it does not affect the defocus, if the same substrate holder is used for a long period of time, small dust will adhere to it, and this dust will contaminate the back side of the semiconductor substrate, and the contaminated semiconductor substrate will contaminate other equipment. The problem is that this creates a vicious cycle.

SUMMARY OF THE INVENTION An object of the present invention is to provide a reduction projection exposure apparatus that can eliminate the above-mentioned problems and improve the yield rate of exposed semiconductor substrates.

[Means for solving problems]

The reduction projection exposure apparatus of the present invention includes a substrate holder that is held on an XY stage and holds a semiconductor substrate, a substrate holder exchange mechanism that replaces the substrate holder, and a substrate holder that cleans the replaced substrate holder. It is configured to include a table cleaning mechanism.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a top view of one embodiment of the present invention.

In FIG. 11, a substrate holding table 1 for vacuum suctioning a semiconductor substrate is held on an X-Y stage 2 having motors 3 and 4. After exposure, the substrate holder 1 from which the semiconductor substrate has been removed is transported into a cleaning tank 8 by a transport arm 5 and a transport belt 6, which constitute a substrate holding and exchanging mechanism.

In the cleaning tank 8, the substrate holding stand 1 is mounted as shown in FIGS.
) is held by a movable arm 11 shown in FIG. 2, and is rotated while being cleaned by pure water and a cleaning brush 12 from a deionized water nozzle 13 constituting a cleaning mechanism. The cleaned substrate holding table 1 is then dried by high-speed rotation of the movable arm 11.

The substrate holding table 1 that has been cleaned is conveyed to the positioning plate 9 by the conveyor belt 7, and positioning is performed. and,
The cleaned and positioned substrate holding stand IA is again carried onto the XY stage 2 by the transfer arm 5 and holds the semiconductor substrate again.

In this manner, in this embodiment, the substrate holding table 1 that once held the semiconductor substrate is constantly cleaned, so that the semiconductor substrate is no longer held with dust attached thereto. Therefore, the occurrence of defocusing in the pattern exposed on the semiconductor substrate is extremely reduced.

As shown in FIG. 3, the substrate holding table 1 is cleaned by immersing the substrate holding table 1 in the cleaning liquid in the cleaning tank 15 using the transfer arm 16, cleaning it using the ultrasonic oscillator 14, and then moving it to the drying chamber 1.
You may use the method of drying in step 7.

〔Effect of the invention〕

As described above, the present invention has the effect of eliminating defocus during exposure of the semiconductor substrate due to dust on the substrate holder by cleaning the substrate holder every time the exposure of the semiconductor substrate is completed. In addition, the dust on the back surface of the semiconductor substrate is transferred to the substrate holding table, and it no longer affects the semiconductor substrates that have flowed thereafter, dramatically improving the quality of products.

[Brief explanation of the drawing]

Fig. 1 is a top view of an embodiment of the present invention, Fig. 2(a), (
b) is a top view and a front view for explaining a substrate holder cleaning mechanism according to an embodiment of the present invention, and FIG. 3 is a sectional view of another example of the substrate holder cleaning mechanism. 1... Substrate holding stand, 2... X-Y stage, 3, 4
...Motor, 5...Transport arm, 6, 7...Transport belt, 8...Cleaning tank, 9...Positioning mechanism, 11
...Movable arm, 12...Washing brush, 13...
Pure water nozzle, 14... Ultrasonic oscillator, 15... Cleaning tank, 16... Transfer arm, 17... Drying room.

Claims (1)

[Claims] A substrate holder that is held on an XY stage and holds a semiconductor substrate, a substrate holder exchange mechanism that replaces the substrate holder, and a substrate holder cleaning mechanism that cleans the replaced substrate holder. Reduction projection exposure equipment.