JPH02275617A - Resist coating device - Google Patents

Abstract

PURPOSE:To enable resist elements near the tip of a nozzle to be maintained and the resist film thickness on a substrate to be kept to a constant by mounting a cap which can be mounted and removed at the tip of the nozzle through an O ring. CONSTITUTION:A cap 3 for blocking is provided at the discharge port of a nozzle 2 through an O-ring 4 which is a packing. Normally, when a resist l exists within the nozzle 2, the resist 1 is sackbacked for preventing drop of liquid after coating resist and a boundary surface 5 of the resist 1 is located at the rear. part from the tip. Since a cap 3 is mounted to the tip of the nozzle 2, the space which the boundary surface 5 contacts is sealed and a solvent of resist from the boundary surface 5 is vaporized, thus filling the can. Therefore, the concentration of solvent environment can be maintained to be constant where the amount of solvent vaporized from the boundary surface 5 and that of solvent dissolved into resist from a solvent environment 6 are balanced, thus preventing viscosity of resist at the tip part and rear part of the nozzle from changing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a resist coating apparatus, and particularly to a resist coating apparatus used for manufacturing semiconductor integrated circuits.

[Conventional technology]

FIG. 3 is a longitudinal cross-sectional view of a nozzle of a resist coating apparatus showing an example of the conventional technique. Conventionally, the nozzle of this type of resist coating device has a resist drying prevention mechanism to prevent the tip from drying out. As shown in FIG. 3, this drying prevention mechanism is implemented by bringing the tip of the nozzle 2 into contact with the opening of the device side receiving part 7 in which the solvent 8 of the resist 1 is sealed, thereby removing the resist attached to the tip of the nozzle. A method of preventing drying by exposing to atmosphere 6 is known.

[Problem to be solved by the invention]

However, in the conventional resist coating apparatus described above,
Since the concentration of the solvent atmosphere in contact with the resist at the nozzle tip cannot be adjusted, the resist component ratio near the nozzle tip (
The disadvantage is that the component ratio (component ratio of polymer and solvent) cannot be kept constant.

Furthermore, when the nozzle tip leaves the device side receiving part for resist coating, the solvent atmosphere diffuses and the solvent continues to vaporize, so the solvent must be replenished from time to time, and the solvent atmosphere is removed from the device. There is a drawback that an exhaust duct must be installed near the receiving part on the side of the device to prevent leakage. If resist components cannot be kept constant, the viscosity of the resist will change, the resist film thickness will not be uniform during resist coating, uneven coating will occur, and pattern dimensional accuracy after etching will be affected.

An object of the present invention is to provide a resist coating device having a nozzle that solves this problem.

[Means to solve the problem]

A resist coating apparatus of the present invention is a resist coating apparatus having a nozzle for dropping a resist liquid for coating a semiconductor substrate with a resist, and includes a cap that closes an ejection port of the nozzle via a packing.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing one embodiment of the nozzle of the present invention. This nozzle is provided with a cap 3 that closes the ejection port via an O-ring 4 which is a packing. Normally, when the resist 1 is present in the nozzle 2, the resist 1 is sucked back (pushed back) to prevent liquid dripping after resist application. Therefore, the boundary surface 5 of the resist 1 is located behind the tip of the nozzle.

Here, a cap 3 is attached to an O-ring 4 at the tip of the nozzle 2.
Since it is attached through the interface, the space where the boundary surface 5 contacts is sealed. As a result, the resist solvent evaporates from the interface 5 and fills the cap. Therefore, when the amount of solvent vaporized from the interface 5 and the amount of solvent dissolved into the resist from the solvent atmosphere 6 are balanced, the concentration of the solvent atmosphere is kept constant.

Next, the operation of this nozzle will be explained. First, the cap 3 of this resist coating device is removed. This makes it ready for coating. At this time, the solvent atmosphere at the tip of the nozzle diffuses, but the amount of solvent lost can be suppressed to a small amount by minimizing the space for the solvent atmosphere.
Changes in resist components are at a negligible level.

For example, a commercially available styrene-based resist is filled into the nozzle of a resist coating device, the resist is taken out from the tip of the nozzle, the resist is sucked back about 5 mm from the tip of the nozzle, and then the resist is placed through the cap and O-ring of the present invention. Connected by hand. After connecting, leave it for one day and remove the cap and zero.
After removing the ring by hand, I immediately coated 10 mask blanks in succession and measured the resist film thickness, all of which were 5.
000±100 people, and no trend change in resist film thickness depending on the order of coating was observed. Moreover, no trend change was observed in the variation in film thickness distribution among the plates from 1 to 10 plates. This means that there was no change in the viscosity of the resist at the tip and rear portions of the nozzle according to the present invention, which suggests that drying at the tip of the nozzle was successfully prevented.

FIG. 2 is a longitudinal sectional view showing a second embodiment of the nozzle of the present invention. In this embodiment, instead of the cap in the previous embodiment, an apparatus-side receiving part 7 is provided on the apparatus side, which functions as a cap. Therefore, there is no need for troublesome removal of the cap by hand as in the above-mentioned embodiments, and the advantage is that it can be handled by fixing the device side receiving part 7 to the device and moving the nozzle 2 up and down. There is.

〔Effect of the invention〕

As explained above, in the present invention, by attaching a removable cap to the tip of the nozzle via an O-ring which is a packing, the resist components near the nozzle tip can be maintained, and the resist film thickness on the substrate can be kept constant. It has the following effects: it is possible to maintain the resist pattern, reduce pattern size variations after etching, and eliminate the need for replenishment of resist solvent.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view showing a first embodiment of the nozzle of the present invention, FIG. 2 is a longitudinal sectional view of the second embodiment of the nozzle of the present invention, and FIG. 3 is a conventional example. FIG. 3 is a longitudinal cross-sectional view of a nozzle of the resist coating device. DESCRIPTION OF SYMBOLS 1...Resist, 2...Nozzle, 3...Cap, 4...O ring, 5...Boundary surface, 6...Solvent atmosphere, 7...Device side receiving part, 8... ··solvent.

Claims (1)

[Claims] What is claimed is: 1. A resist coating apparatus having a nozzle for dropping a resist liquid to apply a resist onto a semiconductor substrate, the resist coating apparatus comprising a cap that closes an ejection port of the nozzle through a packing.