JPS6292442A - Photoresist coating apparatus - Google Patents

Abstract

PURPOSE:To form a photoresist film having uniform thickness by supplying photoresist from a central through hole during low speed rotation without dropping the photoresist from a nozzle above a substrate, and removing the photoresist in the recess formed of the through hole and a center pin at high speed rotation time. CONSTITUTION:Photoresist is supplied through a supply hole 5 formed in a center pin to a through hole 2, and overflowed to be supplied to the surface of a substrate 1. After a chuck table is rotated at a low speed and the entire surface of the substrate is coated with the photoresist, it stops supplying the photoresist, the table is rotated at a high speed, and the photoresist is removed by a photoresist removing mechanism 7 from a recess formed of a center pin 4 and the hole 2. Thus, the photoresist is not flown out from the recess, but a uniform photoresist film can be formed.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a photoresist coating apparatus.

[Conventional technology]

A conventional photoresist coating apparatus, a so-called spin coating apparatus, which drops photoresist onto the center of a substrate and rotates it to spread the coating, is widely used in order to obtain a uniform film.

However, glass substrates used to manufacture optical disks such as compact disks usually have a through hole in the center, and photoresist cannot be dropped in the center of the substrate as in the case without a hole, and the substrate must be rotated at low speed. After dropping photoresist on the outside of the central through hole while rotating, the photoresist layer is formed by rotating at high speed.

Furthermore, when the substrate is mounted on the coating device, it is necessary to align the center of the substrate with the center of rotation, so a center pin that engages with a through hole in the center of the substrate is provided at the center of the chuck table.

[Problem that the invention seeks to solve]

In the conventional coating apparatus described above, the height of the center pin provided at the center of the chuck table greatly affected the uniformity.

For example, if the center pin is higher than the substrate, the photoresist dropped onto the substrate will adhere to the center pin and be pulled away from the center pin during high-speed rotation, resulting in uneven coating.On the other hand, if the center pin is low The disadvantage of this method was that the photoresist fell into the through hole, and during high-speed rotation, the accumulated photoresist flew out and became uneven.

There is still a drawback that the film thickness at the center of the substrate becomes thinner, resulting in non-uniformity, both when the center bin is high and when the center bin is low.

The non-uniform film thickness is caused by the photoresist flowing toward the center due to the flow of the dropped photoresist, which adheres to the center bin, or falls into the recess formed by the through hole and the center bin, which is caused by centrifugal force during high-speed rotation. This is thought to be due to the fact that the photoresist t, which is spread around the outer periphery of the substrate, is insufficient at the center of the substrate.

This is clear if you consider that in a substrate without through holes, the photoresist that has flowed to the center is on the substrate, and this is spread to the outer periphery during high-speed rotation, forming a uniform photoresist film. be.

[Means for solving problems]

As shown in FIG. 1, the photoresist coating device of the present invention is provided with a center bin 4 that is fitted into a through hole 2 at the center of a substrate 1 and is lower than the surface of the substrate, and a photoresist supply hole 5 is provided in the center bin. The photoresist removing mechanism includes a chuck table 3, a photoresist supply mechanism 6, and a photoresist removal mechanism 7.

The photoresist is supplied to the through hole 2 through the supply hole 5 provided in the center bin, overflows, and is supplied to the surface of the substrate 1. After the chuck table is rotated at low speed to coat and spread the photoresist over the entire surface of the substrate, the supply of photoresist is stopped, and at the same time, the chuck table is rotated at high speed and the photoresist is removed from the recess formed by the center bin 4 and the through hole 2. By removing the 7t resist using the mechanism 7, the photoresist does not protrude from the recess, and a uniform photoresist film can be formed.

As the photoresist supply mechanism t7, for example, a suction pump or resist tank pressurization using nitrogen gas can be used.

As the photoresist removal mechanism, suction of the photoresist by reduced pressure, so-called suckback, a mechanism for opening the supply system to the lower side of the chuck table, etc. can be used.

Since the photoresist coating apparatus of the present invention continues to supply photoresist from the through hole at the center of the substrate during low-speed rotation, there is no shortage of photoresist at the center of the substrate during high-speed rotation.

〔Example〕

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

A height of 4 m provided on the chuck table 3 shown in Figure 1.
A through hole 2 with a diameter of lQmm is provided in the center of a glass substrate 1 with an outer diameter of 200mm and a thickness of 5mm in a center bin 4 of
The substrate was placed on the chuck table.

Next, the vacuum chuck part (not shown) provided on the chuck table is depressurized to fix the glass substrate 1, and
The photoresist was supplied to the substrate through the supply hole 5 provided in the chuck table from a photoresist supply tank 6 which was rotated at a low speed of 100 rpm and simultaneously pressurized with nitrogen.

After the supplied photoresist has spread over the entire surface of the substrate, the chuck table is rotated at a high speed of 60 Orpm, and at the same time, the center pin 4 and the through hole 2 are removed by the suck back 7.
The photoresist in the recesses formed was removed by suction.

A photoresist film was formed by rotating at a high speed of 600 rpm for 30 seconds.

The resulting photoresist film had an average thickness of 1000 Å, an increase in thickness near the center of 990 Å, and a film with good uniformity was formed.

〔Effect of the invention〕

Instead of dropping photoresist from a nozzle provided on the substrate, the photoresist coating device of the present invention supplies photoresist from a through hole in the center while rotating at low speed, so that the photoresist in the center becomes insufficient. Furthermore, by removing the photoresist in the recess formed by the through hole and the center bin during high speed rotation, it is possible to form a photoresin film with a uniform thickness.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram showing the complete gloss 9'll of the present invention. 1... one board, 2... shell hole provided in the center of the board, 3... chuck table, 4...
...Center pin, 5...Photoresist supply hole, 6...Fuzu resist supply mechanism, 7...
...Photoresist removal mechanism. 1st Figure 4 °C Letter Hind

Claims (1)

[Claims] a chuck table having a center pin that is engaged with a through hole in the center of the substrate and is lower than the surface of the substrate, and a photoresist supply hole provided in the center pin; a mechanism that supplies photoresist from the supply hole; A photoresist coating device comprising a center pin and a mechanism for removing photoresist from the recess formed by the through hole.