JPH01234851A - Developing device for optical disk - Google Patents

Abstract

PURPOSE:To form a uniform pattern in the entire area of a glass substrate by comparing the pattern width of an innermost area in a pattern area on the glass substrate with that of an outermost area and dripping a liquid developer from a nozzle in the intermediate pattern area when the pattern width of the outermost area is smaller. CONSTITUTION:When the liquid developer 3 is dripped from only the nozzle inside the pattern area while the glass substrate 2 which is exposed the pattern is rotated spirally, the liquid developer 3 flows on the glass substrate 2 from inside to outside to perform development processing. While the development is advanced, laser beam is projected perpendicularly on two points in the innermost area and outermost area of the pattern area simultaneously at all the times and an arithmetic unit 10 calculates the pattern width. Then when the pattern width (x) of the innermost pattern area is larger than the pattern width (y) of the outermost area, a comparator 12 sends an indication to a solenoid valve 11 so as to drip the liquid developer from the nozzle in the intermediate pattern area, but when smaller, an instruction is sent to the solenoid valve 11 so as to drip pure water from the nozzle in the intermediate pattern area. Consequently, the uniform pattern is formed over the entire surface of the substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a developing device for optical discs, and in particular, to a developing device for optical disks, in which a pattern is exposed concentrically or spirally at two constant pitches on a glass substrate. The present invention relates to a developing device for optical discs.

[Conventional technology]

A conventional optical disk developing device is, for example, Matsushita Electric Technical Report V.
As shown in OL, 29 "Preparation of Master Optical Disc Using NC1,5R Laser", an automatic developing device with a development monitor is widely known as a device for developing a pattern exposed at a constant pitch on a glass substrate. There is.

In conventional optical disc development devices, laser light is passed perpendicularly through the glass substrate during development, and the pattern structure that appears as development progresses acts as a diffraction grating for the laser light, producing diffracted light. . Since the diffracted light also changes as the pattern width changes, this is detected and the pattern width is monitored, and the development process is terminated when the required pattern width is formed.

Next, a conventional optical disc developing device will be described with reference to the drawings.

FIG. 2 is a block diagram showing an example of a conventional optical disk developing device. The developing method involves vacuum suctioning the glass substrate 2 to a spin chuck L, and developing by dropping the developer 3 supplied by the developer supply nozzle 4 onto the glass substrate 1 while rotating the glass substrate 2. It uses a so-called spin development method.

A He-Ne laser 5 is irradiated perpendicularly from the back surface of the glass substrate 1, and after the diffracted light transmitted through the glass substrate 1 is emitted, a pattern width is calculated by an arithmetic unit 10.

The development process ends when the required pattern width is formed.

[Problem to be solved by the invention]

However, the above-mentioned conventional optical disc development device is configured to irradiate a laser beam onto one spot on the glass substrate and monitor the pattern width, so the pattern width on other parts of the glass substrate is Factors that are completely unknown and affect the development conditions before the development process include the photoresist film thickness and the amount of exposure per unit area, but spin codes are generally used in the photoresist coating process, and the The variation in thickness is greater in the radial direction than in the circumferential direction, and in the exposure process, for example, in the case of an optical disk, the exposure power is increased from near the center toward the outer edge so that the amount of exposure per unit area becomes constant. Even if controlled, the state of the laser changes over time, which still appears as a difference in the radial direction.Furthermore, the development process is spin development, and the developer is generally supplied from a nozzle fixed near the center of the glass substrate. Since the developer supplied to the outer edge has already been used for development near the center,
There is a large difference in the progress of development between near the center and the outer edge of the glass substrate, and there are also known configurations in which the nozzle is driven from near the center towards the outer edge, or from the outer edge towards the center. The disadvantage of this monitor is that it is extremely difficult to control the pattern width over the entire surface of the substrate.

[Means to solve the problem]

The developing device for optical discs of the present invention includes a rema, a spin chuck, and inside and inside the pattern area of a glass substrate that is held and rotated by the subinci yak and exposed with a concentric or spiral pattern at a constant pitch. two sets of developer supply nozzles that are provided at two locations in the pattern area and can control the dropping of developer and pure water in at least the middle area of the pattern area; An optical system that vertically irradiates a laser beam onto a point, two sets of diffracted light amount detectors that detect the amount of diffracted light of the 0th order light and ±1st order light due to the pattern on the substrate of the laser beam, and a pattern width that is determined based on the detected light amount. and a comparison circuit that compares the pattern widths, and when the outermost pattern width is small, the developer is dripped from the nozzle in the middle of the pattern, and when the outermost pattern width is large, pure water is dripped from the nozzle in the middle of the pattern. It consists of:

〔Example〕

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

FIG. 1 is a schematic diagram showing an embodiment of the present invention.

The optical disk developing device shown in FIG. 1 consists of a spin chuck 1 and a glass substrate 2 held by the spin chuck and rotated to expose a concentric or spiral pattern at a constant pitch. Two sets of developer supply nozzles 4 are provided at two locations in the middle of the pattern area (both are two sets of developer supply nozzles 4 that can control the dropping of developer 3 and pure water in the middle of the pattern area, and one at the top of the pattern area of this glass substrate. He-N for perpendicularly irradiating laser light to two points, the inner region and the outermost region.
e laser 5, half mirror 6, total reflection mirror 7,
Two sets of diffracted light amount detection unit 8 and amplifier 9 detect the amount of diffracted light of 0th order light and ±1st order light by this laser light pattern.
and a calculation unit 1 that calculates the pattern width from the detected light amount.
0, the innermost area pattern width and the outermost area pattern width calculated by the arithmetic unit 10 are compared, and when the outermost area pattern width is small and the outermost area pattern width is large, the solenoid valve 11 is configured to drop pure water from the nozzle in the middle area of the pattern. Comparison circuit that issues instructions to
2.

Next, an example of the operation of the optical disk developing device shown in FIG. 1 will be described.

For example, photoresist product name MP1350 manufactured by Sibley
The glass substrate 2, on which a spiral pattern was exposed with a pitch of 1.6 μm, was coated with J to a film thickness of 1200 μm.
While rotating at pm, a developer 3 of MP Developer manufactured by Sibley Co., Ltd. with a concentration of 20% is dripped onto the glass substrate 2 from only the nozzle inside the pattern area. The developer 3 flows over the glass substrate 2 from the inside to the outside to perform a development process. During development, laser light is always perpendicularly irradiated to two points, the innermost area and the outermost area, of the pattern area at the same time, and the pattern width is calculated by the calculation unit 10.

Assuming that the pattern width of the innermost area of the pattern is x and the pattern width of the outermost area of the pattern is y, if the relationship x>y is established as development progresses, then the comparison circuit 12 will cause the nozzle in the middle area of the pattern to develop the pattern. An instruction is issued to the solenoid valve 11 to drip the liquid.

Further, as the development progresses, the relationship x=y is established, so at this time the comparator circuit 12 issues an instruction to the electromagnetic valve 11 to stop dropping the developer from the nozzle in the middle area of the pattern.

Conversely, if the relationship x<y holds true, then the comparison circuit 12 issues an instruction to the electromagnetic valve 11 to drip pure water from the nozzle in the middle area of the pattern.

As the development progresses further, the relationship x=y is established, so at this time the comparator circuit 12 issues an instruction to the electromagnetic valve 11 to stop dripping pure water from the nozzle in the middle area of the pattern.

By repeating the above steps, a uniform pattern is formed over the entire surface of the substrate.

In the above embodiment, a three-way valve was used to supply the developer and pure water to the middle area of the pattern with one nozzle, but two nozzles were used, one for the developer and one for the pure water. It's okay.

〔Effect of the invention〕

The optical disk developing device of the present invention includes two sets of 00th order light, ±1
A diffraction light amount detection unit for the secondary light is installed, and the pattern width is monitored in two places, the innermost area and the outermost area, of the pattern area in-process during development, and the pattern widths in the innermost area and the outermost area are compared, and the pattern width is compared in the outermost area. When the pattern width becomes small, developer is dropped from the nozzle in the middle area of the pattern area, and when the pattern width in the outermost area becomes large, pure water is dropped from the nozzle in the middle area of the pattern area. This has the effect of forming a uniform pattern over the entire substrate.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of the present invention, and FIG. 2 is a schematic diagram showing a conventional example. 1... Spin chuck, 2... Glass substrate, 3... Developer, 4... Developer supply nozzle, 5... He -Ne laser, 6...
... Half mirror 17 ... Total reflection mirror, ... Light amount detection section, 9 ... Amplifier, 10.
...Calculation unit, 11...Solenoid valve, 1
2... Comparison circuit. Agent Patent Attorney Uchihara Ondai 1 Bacteria $ 2 Diagram

Claims (1)

[Claims] A spin chuck and a glass substrate which is rotated while being held by the spin chuck and is exposed with a concentric or spiral pattern at a constant pitch. Two sets of developer supply nozzles that can control the dropping of developer and pure water in the middle area, and optics that vertically irradiate laser light to two points, the innermost area and the outermost area of the pattern area of the glass substrate. a system, two sets of diffracted light amount detection units that detect the amount of diffracted light of the 0th order light and ±1st order light due to the pattern on the substrate of the laser beam, an arithmetic unit that calculates the pattern width from the detected light amount, and the pattern width. an optical disc characterized in that it includes a comparison circuit that compares the pattern width of the outermost area and drops a developer from a nozzle in the middle area of the pattern when the pattern width of the outermost area is small, and drops pure water from the nozzle of the middle area of the pattern when the pattern width of the outermost area is large. development equipment.