JP6857585B2 - Exposure device - Google Patents

Description

The present invention relates to an exposure apparatus that exposes a pattern on a substrate without using a mask.

A direct drawing exposure apparatus is known in which a plurality of semiconductor lasers (hereinafter referred to as LD) are provided as a light source in order to form a wiring pattern or the like on a printed circuit board, and the substrate is directly exposed without using a mask. In such a direct drawing exposure apparatus, if the output decreases due to the deterioration of the LD, the exposure becomes poor and the throughput decreases.

In order to prevent such exposure defects, when detecting a decrease in the output of the LD that generates the exposure illumination light, as disclosed in FIG. 1 of Patent Document 1, the exposure illumination light branched by the beam splitter is emitted. There is a technique for detecting with a detector, but there is a problem that a beam splitter must be provided exclusively for branching the exposure illumination light, and the light intensity of the exposure illumination light is lowered.

Japanese Unexamined Patent Publication No. 2004-039871

An object of the present invention is to provide an exposure apparatus capable of solving the above-mentioned problems and detecting a decrease in light intensity of exposure illumination light with a simple configuration.

In order to solve the above problems, among the inventions disclosed in the present application, a typical exposure device is an exposure device including an exposure light source that outputs illumination light for exposing a substrate and includes a plurality of semiconductor lasers. Detects a modulator having a glass disk whose illumination light is vertically incident on a plane and is driven to rotate in the circumferential direction of the glass disk, and the intensity of the illumination light leaking through the glass disk. It is characterized by providing a detecting means for controlling the internal operation based on the comparison result in comparison with a threshold value in which the intensity is stored in advance.

According to the present invention, it is possible to detect a decrease in the light intensity of the exposure illumination light with a simple configuration.

It is an overall block diagram of the direct drawing exposure apparatus which concerns on this invention. It is a figure for demonstrating the illumination optical system which concerns on this invention.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In the following description, the same reference numerals are given to the equivalent parts, and the description thereof will be omitted.

FIG. 1 is an overall configuration diagram of a direct drawing exposure apparatus according to an embodiment of the present invention. Reference numeral 1 denotes an exposure illumination unit. Reference numeral 2 denotes an illumination optical system, and the exposure illumination light 3 emitted from the illumination optical system is incident on the two-dimensional space modulator 5 above by the mirror 4. Here, since the digital mirror device is used as the two-dimensional space modulator 5, the two-dimensional space modulator is referred to as DMD.

In DMD5, a large number of movable micromirrors are arranged in a matrix in the XY plane. When an ON / OFF signal is sent from the control device 6 to be described later to each micromirror, the micromirror that receives the ON signal tilts at a constant angle and reflects the incident exposure illumination light to be incident on the first projection lens 7. .. Further, the exposure illumination light 3 reflected by the micromirror in the OFF state does not enter the first projection lens 7 and does not contribute to the exposure. The exposure illumination light transmitted through the projection lens 7 is incident on the microlens array 8. Microlenses are arranged at the positions of the microlens array 8 on which the magnified image (or reduced image) of the micromirror of the DMD 5 is formed. The exposure illumination light 3 (exposure illumination light coming from the micromirror in the ON state) incident on each microlens substantially perpendicularly is incident on the second projection lens 9, and the exposure illumination light 3 emitted from the second projection lens 9 is emitted. Form an exposure pattern in the irradiation area 11 on the substrate 10.

Reference numeral 6 denotes, for example, a control device realized by a program-controlled processing device as a main body, which controls the operations of the illumination optical system 2, the DMD 5, and the stage 12 in the exposure illumination unit 1. Reference numeral 13 denotes a stage drive unit, which moves the stage 12 in the X, Y, and Z directions in response to a control command from the control device 6.

FIG. 2 is a diagram for explaining the illumination optical system 2 in FIG. Reference numeral 14 denotes an exposure light source, which is composed of blue and purple LDs that emit light having a wavelength of about 405 nm (380 to 420 nm) at an output of about 400 mW in a two-dimensional arrangement on a substrate. The light emitted from each LD passes through the diffuser 16 by the condenser lens (condensing optical system) 15 and then enters the optical integrator 19. The diffuser 16 is a modulator that changes the wave surface, and is composed of a glass disk 17 that is rotated by driving a directly connected motor 18. The glass disk 17 is optically polished radially, and the shape of the glass surface has a substantially sinusoidal height change. The amount of change in height (roughness) is several μm. The light transmitted through the optical integrator 19 passes through the condenser lens (collimating lens) 20, is reflected by the mirror 4, and irradiates the DMD 5. The optical integrator 19 spatially decomposes the luminous flux emitted from a large number of LDs arranged in two dimensions condensed by the condensing lens 15 to generate a large number of pseudo secondary light sources, and illuminates them in an overlapping manner. It is a system. Reference numeral 21 denotes a photodetector, which detects leakage light propagated in the glass disk 17 by the exposure illumination light 3. The exposure light source 14 and the motor 18 are controlled by the control device 6.

Next, the operation of this embodiment will be described.

The stage 12 on which the substrate 11 is mounted is moved at a constant speed according to the photosensitive material from the back side to the front side in the X direction in FIG. 1, and the substrate 10 is irradiated with the exposure illumination light 3. The photodetector 21 detects the leaked light from the diffuser 16 at regular time intervals. When the photodetector 21 is connected to the control device 6 and the detection value of the detector 21 when the leaked light is detected by the control device 6 is lower than the threshold value stored in advance in the control device 6, an exposure light source error occurs. An alarm is issued to stop the exposure.

In the above embodiment, when the intensity of the exposure illumination light is lower than the threshold value, the exposure is stopped, but instead, the drive level of the LD of the exposure light source 14 is increased so that the exposure operation can be continued. Is also good.

According to the above embodiment, the decrease in the intensity of the exposure illumination light 3 can be detected without decreasing the light intensity of the exposure illumination light 3 with a simple configuration. Further, since the detector 21 is provided at a position relatively close to the exposure light source 14, it is possible to detect with high sensitivity.

In the above-described embodiment, the case where one exposure illumination unit 1 is arranged with respect to the substrate 10 has been described, but two or more exposure illumination units 1 may be provided in the Y direction and exposed at the same time. In this case, since the area to be exposed at one time increases, the throughput can be improved.

The present invention is not limited to the above embodiment, and various modifications can be made, and all the technical matters included in the technical idea described in the claims are the subject of the present invention.

1 Exposure illumination unit 2 Illumination optical system 3 Exposure illumination light 4 Mirror 5 DMD
6 Control device 7 1st projection lens 8 Micro lens array 9 2nd projection lens 10 Substrate

Claims (1)

In an exposure apparatus including an exposure light source that outputs illumination light for exposing a substrate and includes a plurality of semiconductor lasers.
A modulator having a glass disk whose illumination light is vertically incident on a plane and driven to rotate in the circumferential direction of the glass disk, and detection for detecting the intensity of the illumination light leaking through the glass disk. An exposure apparatus characterized in that a means and a control means for controlling an internal operation based on the comparison result in comparison with a threshold value in which the intensity is stored in advance are provided.

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