JP2504188B2 - Optical disc master exposure device - Google Patents

Description

The present invention relates to an optical disk master exposure apparatus.

[Conventional technology]

In the conventional optical disc master exposure apparatus, in order to control the power of the exposure beam, it is common to sample the beam on a fixed optical system and monitor it to control the optical modulator.

 FIG. 2 is a block diagram showing a conventional example.

The optical disk master exposure apparatus shown in FIG. 2 is a head that detects the distance between the rotation center axis of the rotating photoresist substrate 1 and the center axis of the head lens 10 on the moving optical system A ', and outputs a head position detection signal a. A position detector 17, an exposure amount setting unit 4 in which the exposure beam intensity for the head position detection signal a is preset as an exposure amount setting signal b, and light for adjusting the intensity of the laser beam 3 emitted from the laser oscillator 2. The modulator 6 and the beam emitted from the optical modulator 6 are sampled by the beam sampler 18 on the fixed optical system B ', and the monitor beam 20 obtained is detected to detect the optical sensor output signal g.
The optical modulator drive signal f is adjusted so that the exposure amount setting signal b and the optical sensor output signal g coincide with the optical sensor unit 19 on the fixed optical system B ′ that outputs the optical modulator 6. The optical modulator driving unit 5 for driving is included.

At the time of exposure, the head position detection unit 17 detects the distance between the rotation center axis of the rotating photoresist substrate 1 and the center axis of the head lens 10.

The exposure amount setting unit 4 outputs an exposure amount setting signal b for the head position detection signal a. The intensity of the laser beam 3 emitted from the laser oscillator 2 is adjusted by the optical modulator 6, and the optical sensor section 19 on the fixed optical system B ′ controls the beam emitted from the optical modulator 6 on the fixed optical system B ′. Beam sampler
The monitoring beam 20 sampled at 18 is detected.

The optical modulator drive unit 5 adjusts and outputs the optical modulator drive signal f so that the exposure amount setting signal b and the optical sensor output signal g match, drives the optical modulator 6, and drives the laser beam 3. Adjust strength.

The exposure beam 7 whose intensity is adjusted by the optical modulator 6 is bent by the beam splitter 9 on the moving optical system A ′, passes through the head lens 10, is irradiated on the photoresist substrate 1, and is exposed.

[Problems to be Solved by the Invention]

However, in the above-described conventional optical disk master exposure apparatus as described above, the output beam of the optical modulator is monitored on the fixed optical system, and the intensity of the exposure beam is adjusted. Due to the gap
The intensity of the exposure beam actually radiated on the photoresist substrate may fluctuate due to deviations in the incidence on each optical element of the optical system after the beam sampler, or due to changes in the state of each optical element. There is a drawback that exposure cannot be performed due to the intensity of the exposure beam.

[Means for solving the problem]

The optical disk master exposure apparatus of the present invention is an optical disk master exposure apparatus having an optical system including a head for focusing and converging an exposure laser beam on at least a photoresist substrate as a moving optical system, and the exposure beam reflected by the photoresist substrate. Is detected from the exposure optical system, a reflectance monitor unit that detects the focusing focusing laser beam reflected by the photoresist substrate on the movable optical system, and the reflectance monitor unit. An exposure amount correction unit that corrects the exposure amount detection signal obtained from the exposure amount detection unit with a reflectance monitor signal, an exposure amount setting unit preset corresponding to the position of the head, and an exposure amount setting unit Modulator driving for controlling the optical modulator so that the exposure amount setting signal and the corrected detected exposure amount signal obtained from the detected exposure amount correcting unit coincide with each other. Configured to have a door.

[Embodiment] Next, an embodiment of the present invention will be described with reference to the drawings.

 FIG. 1 is a block diagram showing one embodiment of the present invention.

The optical disk master exposure apparatus shown in FIG. 1 includes a head position detection unit 17 that detects a distance between the rotation center axis of the rotating photoresist substrate 1 and the center axis of the head lens 10 and outputs a head position detection signal a, An exposure amount setting unit 4 in which the intensity of the exposure beam with respect to the head position detection signal a is preset by the exposure amount setting signal b, an optical modulator 6 for adjusting the intensity of the laser beam 3 emitted from the laser oscillator 2,
The exposure beam 7 emitted from the optical modulator 6 is bent by the beam splitter 9, transmitted through the head lens 10, and the exposure amount monitor beam 11 reflected by the photoresist substrate 1 is detected on the moving optical system A. The portion 12 and the focusing laser beam 8 are reflected by the photoresist substrate 1,
A reflectance monitor unit for detecting the reflectance monitor beam 14 extracted by the dichroic mirror 13 on the moving optical system A.
15 and a detected exposure amount correction unit 16 for correcting the exposure amount detection signal c obtained from the exposure amount detection unit 12 with the reflectance monitor signal d obtained from the reflectance monitor unit 15 and outputting a corrected detected exposure amount signal e. And an optical modulator drive unit 5 for driving the optical modulator 6 by adjusting the optical modulator drive signal f so that the exposure amount setting signal b and the corrected detection exposure amount signal e match. To be done.

At the time of exposure, the distance between the rotation center axis of the rotating photoresist substrate 1 and the center axis of the head lens 10 is measured by the head position detection unit.
17 detects.

The exposure amount setting section 4 outputs an exposure amount setting signal b for the head position detection signal a. At this time, the exposure amount setting signal b is based on the assumption that the beam reflectance on the photoresist substrate 1 is 1.

The laser beam 3 emitted from the laser oscillator 2 becomes an exposure beam 7 whose intensity is adjusted by the optical modulator 6, and is bent by the beam splitter 9 on the moving optical system A,
The light passes through the head lens 10 and is applied to the photoresist substrate 1.

The exposure amount detection unit 12 on the moving optical system A uses the exposure amount monitor beam reflected according to the reflectance of the photoresist substrate 1.
11 is received.

Further, the focusing laser beam 8 is a head lens.
After passing through 10, the photoresist substrate 1 is irradiated. The reflectance monitor unit 15 on the moving optical system A is reflected according to the reflectance of the photoresist substrate 1, and the dichroic mirror 13
The reflectance monitor beam 14 extracted in step 1 is received, and the reflectance of the photoresist substrate 1 is calculated and output.

The detected exposure amount correction unit 16 divides the exposure amount detection signal c by the reflectance monitor signal d to calculate the detected exposure amount when the reflectance is 1, and outputs it as a corrected detected exposure amount signal e.

The optical modulator drive unit 5 adjusts and outputs the optical modulator drive signal f so that the exposure amount setting signal b and the corrected detection exposure amount signal e are matched with each other, drives the optical modulator 6, and outputs the laser light. Adjust the intensity of the beam 3.

〔The invention's effect〕

The optical disk master exposure apparatus of the present invention detects the exposure beam reflected from the photoresist substrate at the time of exposure by an optical sensor provided on the moving optical system, monitors the exposure amount of the head emission, and controls it. There is an effect that the variation of the intensity of the exposure beam on the photoresist substrate due to the misalignment of alignment and the change of the state of the optical element can be eliminated, and the exposure can be performed with a desired intensity of the exposure beam.

Further, at this time, a part of the focusing beam reflected from the photoresist substrate is detected by an optical sensor provided on the moving optical system as a reflectance monitor beam, and the reflectance of the photoresist substrate is calculated, By removing the exposure beam intensity reflected from the photoresist substrate,
Eliminating the fluctuation of the exposure beam intensity due to the fluctuation of the reflectance of the photoresist substrate due to the photoresist film thickness,
There is also an effect that the exposure amount emitted from the head can be accurately monitored.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional example. 1 ... Photoresist substrate, 2 ... Laser oscillator, 3 ...
... laser beam, 4 ... exposure amount setting part, 5 ... light modulator driving part, 6 ... light modulator, 7 ... exposure beam, 8 ... focusing laser beam, 9 ... beam splitter, 10
...... Head lens, 11 …… Exposure amount monitor beam, 12 ……
Exposure amount detection unit, 13 ...... dichroic mirror, 14 ...... Reflectance monitor beam, 15 ...... Reflectance monitor unit, 16 ...... Detection exposure amount correction unit, 17 ...... Head position detection unit, 18 ...... Beam sampler , 19 ... Optical sensor section, 20 ... Monitor beam, a ... Head position detection signal, b ... Exposure amount setting signal, c ... Exposure amount detection signal, d ... Reflectance monitor signal,
e: correction detection exposure amount signal, f: optical modulator drive signal,
g ... Optical sensor output signal, A, A '... Moving optical system, B, B'
...... Fixed optical system.

Claims (1)

(57) [Claims] 1. An exposure amount detection unit for focusing and converging an exposure laser beam on at least a photoresist substrate and detecting an exposure beam reflected by the photoresist substrate on a moving optical system; A reflectance monitor unit for detecting the focused focusing laser beam on the moving optical system, and a detection for correcting the exposure amount detection signal obtained from the exposure amount detection unit by the reflectance monitor signal obtained from the reflectance monitor unit. An exposure amount correction unit, an exposure amount setting unit preset corresponding to the position of the head, an exposure amount setting signal obtained from the exposure amount setting unit, and a corrected detection exposure amount signal obtained from the detected exposure amount correction unit And a modulator driving unit for controlling an optical modulator such that