JPS61276320A - Photoresist exposure device - Google Patents

Abstract

PURPOSE:To prevent insufficient exposure by providing a detector for detecting the emitting power of a laser and a controller for controlling the amplitude of a rectangular signal input to a modulator when emitting a modulated argon laser beam to a photoresist while relatively moving the photoresist applied on a support. CONSTITUTION:A laser light from an argon laser 1 is emitted and through a condensing lens 3 to a photoresist 4 applied on a support such as a glass disk while relatively rotating, and the receipt 4 is formed by developing into the prescribed pattern. In this structure, a detector 5, a modulator 2 and an amplitude compensator 6' are provided between the laser 1 and the lens 3, a beam reflected by a half mirror 51 in the detector 5 is detected by a photodiode 52, compared with the prescribed value, and a compensation signal C is fed from an auxiliary signal output circuit 53 to the compensator 6' when the beam is lower than the prescribed value. An output from the compensator 6' is applied through a supersonic modulator 21 in the modulator 2 to an acoustic optical modulator 22, ad the reduction in the radiating power is compensated by the output.

Description

[Detailed Description of the Invention] [Summary] A photoresist exposure apparatus that selectively exposes a photoresist (photosensitive film) with an amplitude-modulated argon laser beam, which reduces the instantaneous radiation power of the argon laser. Exposure accuracy was improved by compensating the structure.

[Industrial application field]

The present invention relates to a photoresist exposure apparatus used for manufacturing photoresist masters for optical disks.

For example, a stamper (mold) used in the molding process of optical discs moves a positive photoresist coated onto a disk of glass or the like in a spiral manner using a laser beam whose amplitude is modulated according to recorded information. irradiate while
By treating this with a developer and melting and removing the exposed portion, a photoresist master, which is a primary matrix, is made 9
Next, it is made from the primary matrix through processes such as plating.

As the laser beam, an argon laser beam is generally used for reasons such as wavelength and output.

However, the argon laser temporarily has a
A so-called dropout, which is a phenomenon in which the radiation power decreases by 50 to 80% over μs, may occur, but it is currently extremely difficult to completely prevent this.

Therefore, it is desirable that a photoresist exposure apparatus using an argon laser as a light source be configured to prevent product defects due to dropouts.

[Conventional technology]

FIG. 3 is a block diagram of a conventional example of a photoresist exposure apparatus used for manufacturing a photoresist master disk for an optical disk.

1 is an argon laser.

2 is a modulation unit that modulates the amplitude of the laser beam emitted by the argon laser 1 using a rectangular wave signal.

3 is a condensing lens.

4 is a photoresist coated on a substrate (not shown) such as a glass disk.

The modulation unit 2 is an ultrasonic modulator 2 that amplitude-modulates, for example, a 30 MHz ultrasonic signal using a rectangular-wave analog signal A with a constant amplitude corresponding to a write signal and outputs the amplitude-modulated ultrasonic signal.
1, and an acousto-optic modulator (AOM) 22 that modulates a laser beam with the output B of the ultrasonic modulator 21.

The photoresist 4 is rotated together with the glass disk at a predetermined constant speed by a drive motor (not shown).

On the other hand, the laser beam modulated by the modulator 2 and condensed by the condensing lens 3 is deflected in the radial direction of the glass disk at a predetermined speed by a deflection device 9 (not shown).

As a result, the photoresist on the glass disk.

A primary matrix is created by selectively exposing the spiral to light and treating it with a developer.

[Problem that the invention seeks to solve]

In the apparatus having the above configuration, it is not uncommon for exposure to take a long time, for example, one hour or more.

Argon laser dropouts occur once every few hours.

For this reason, there is a problem in that, for example, one out of several photoresist masters is defective, which increases manufacturing costs.

Therefore, two objects of the present invention are to provide a photoresist exposure apparatus that can prevent product defects due to dropouts.

[Means for solving problems]

FIG. 1 is a diagram showing the principle of the present invention.

5 is a detection unit that detects the radiation power of the argon laser 1;

Reference numeral 6 denotes a control unit that controls the amplitude A of the rectangular wave signal input to the modulation unit 2 based on the detection value of the detection unit 5.

[Effect]

That is, the radiation power of the argon laser 1 is detected by the detection section 5, and if the detected value drops below a predetermined value, for example, the amplitude of the rectangular wave signal input to the modulation section 2 is increased and the modulation section 2 is modulated. By increasing the output, underexposure due to dropout is prevented.

〔Example〕

FIG. 2 is a configuration diagram of the embodiment.

The detection unit 5 includes a half-mirror 51, a photodiode 52 that receives the laser beam reflected by the semi-transparent mirror 51, and compares the detection value detected by the photodiode 52 with a predetermined value, and determines the predetermined value. and a sexual compensation signal output circuit 53 which outputs a sexual compensation signal C while the voltage is below the level.

The control section 6 includes an amplitude compensation circuit 6' that compensates the amplitude of a rectangular wave analog signal A having a constant amplitude given as a write signal in accordance with a compensation signal C.

That is, when the radiation power of the argon laser 1 decreases due to dropout, the output of the acousto-optic modulator 22 is increased by increasing the amplitude of the rectangular wave input to the ultrasonic modulator 21.

(Effects of the Invention) As explained above, according to the present invention, the decrease in the radiation power of the argon laser due to dropout can be compensated for by the modulator 2.

It is possible to prevent product defects due to dropouts during photoresist exposure.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle of the present invention. FIG. 2 is a configuration diagram of the embodiment. FIG. 3 is a configuration diagram of a conventional example. In the figure. 1 is an argon laser, 2 is a modulation section. 3 is a condenser lens, 4 is a photoresist. 5 is a detection unit, and 6 is a control unit. 21 is an ultrasonic modulator, and 22 is an acousto-optic modulator. Hon Akebono's title rhyme No. 1 岨 Kai 2 mouths

Claims (1)

[Claims] Argon laser (1) that emits an argon laser beam
and a modulation unit (2) that modulates the amplitude of the argon laser beam using a rectangular wave signal, the modulating unit (2) modulating the amplitude of the argon laser beam using the modulated argon laser beam while relatively moving the photoresist (4) coated on the support. In a photoresist exposure device that irradiates and selectively exposes light, a detection unit (
5), and a detection unit (
5) A photoresist exposure apparatus characterized by comprising a control section (6) that performs control based on the detected value of step 5).