JPH08304732A - Slit light irradiation optical system - Google Patents

Abstract

(57) [Summary] [Object] To provide a slit light irradiation optical system capable of generating uniform laser slit light with a simple configuration and irradiating a wide material surface with uniform slit light. [Structure] The cylindrical integrator 2 has a strip-shaped cylindrical lens surface 2a on the surface thereof, and splits and condenses the incident laser light 1 and then superimposes them. After that, the laser light is incident on the cylindrical lens 5 having the generatrix 5b orthogonal to the direction of the cylindrical integrator generatrix 2b. Since the respective bus lines 2b and 5b are orthogonal to each other, each laser beam is directed to a single point F by the cylindrical lens in the bus line direction of the cylindrical integrator.
The light is focused so as to be narrowed down to 5, and is also focused on the same plane in the direction of the generatrix 5b. Therefore, slit light having uniform power distributions P1 and P2 in the longitudinal direction and the width direction is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slit light irradiation optical system, and more particularly to a slit light irradiation optical system for shaping a laser light into uniform slit light and irradiating the slit light.

[0002]

2. Description of the Related Art A method of irradiating a laser beam to change the chemical or physical property of a material surface is applied in various fields. In this case, as a method of irradiating the material surface with laser light, a method of irradiating the laser light in the form of minute spots is used. There is known a method of scanning the. However, this method has a drawback that it takes time to scan a wide material surface because the laser beam is spot-shaped.

Further, if scanning is performed using a slit-shaped laser beam, the scanning time is shortened, but there is a problem that it is difficult to obtain slit light having a uniform distribution.

[0004]

SUMMARY OF THE INVENTION Therefore, the present invention has been made in view of the above points, and can generate uniform laser slit light with a simple structure and irradiate a wide material surface with uniform slit light. It is an object of the present invention to provide a slit light irradiation optical system that can be performed.

[0005]

In order to solve this problem, the present invention has a cylindrical lens surface in the form of a strip, in which incident laser light is divided and condensed at each cylindrical lens surface and then superposed. An integrator, having a busbar orthogonal to the busbar direction of the cylindrical integrator, a configuration comprising a cylindrical optical element that collects laser light from the cylindrical integrator and generates slit light in a direction orthogonal to the busbar direction of the cylindrical integrator. It was adopted.

[0006]

In such a structure, the cylindrical integrator has a strip-shaped cylindrical lens surface on its surface, and the laser beams incident on the respective cylindrical lens surfaces are divided and condensed and then superposed on each other. The laser light thus formed by the cylindrical integrator is incident on the cylindrical optical element having a generatrix orthogonal to the generatrix direction of the cylindrical integrator. Since the generatrix of this cylindrical optical element is orthogonal to the generatrix direction of the cylindrical integrator, the laser light is condensed in the generatrix direction of the cylindrical integrator so that it is focused by the cylindrical optical element, while the laser light of the cylindrical integrator is condensed. In the direction orthogonal to the generatrix, the light is superimposed and condensed on the same surface, so that slit light that extends uniformly in the generatrix direction of the cylindrical optical element is formed. This slit light has a uniform power distribution that is trapezoidal in the longitudinal direction and pointed in the width direction, and realizes a slit light irradiation optical system capable of speeding up.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the drawings.

FIG. 1 shows a first embodiment of the present invention. In the figure, 1 is an excimer laser beam.
The excimer laser light 1 is incident on a cylindrical integrator 2 composed of a plurality of strip-shaped cylindrical lens surfaces in which each generatrix is arranged in parallel in the vertical direction. The optical path of the laser light from the cylindrical integrator 2 is bent by the mirrors 3 and 4, so that the entire device is downsized. The laser light deflected by the mirror 4 is incident on the slit light generating cylindrical lens 5 whose generatrix is arranged so as to be in a direction perpendicular to the generatrix of the lens surface of the cylindrical integrator 2, and is made to enter the substance 6 to be surface-modified. It is incident.

FIG. 2 is a conceptual diagram showing an optical system in which the mirrors 4 and 5 are omitted in the embodiment shown in FIG. As is clear from FIG. 2A, the cylindrical integrator 2 is composed of a plurality of cylindrical lens elements, and a strip-shaped cylindrical lens surface 2a is formed on the laser light incident surface thereof. Further, it is understood that the generatrix 2b of the cylindrical integrator 2 ((B) of FIG. 2) is orthogonal to the generatrix 5b of the cylindrical lens 5.

The function of the optical system having the above configuration will be described.

Generally, an excimer laser in the ultraviolet region is used for surface modification of a substance. The excimer laser has a beam profile as shown in FIG. That is, the beam cross-sectional shape is a rounded rectangular shape,
The power distribution in the long side direction (A) is trapezoidal, and the short side direction (B)
Is similar to the Gaussian distribution.

The excimer laser is made incident with its short side direction aligned with the direction of the generatrix 2b of the cylindrical integrator 2. As shown in FIG. 2A, the incident light 1 from the excimer laser is split by each of the strip-shaped cylindrical lens surfaces 2a and once condensed at the focal point F2, they are diverged and overlap each other. Focus F2
The laser beam focused on the laser beam linearly extends perpendicularly to the paper surface of FIG. On the other hand, as shown in FIG. 2B, since the laser beam 1 is not focused in the direction of the generatrix 2b of the cylindrical integrator 2, the laser beam 1 extends behind the cylindrical integrator 2 with its width substantially unchanged. I will go.

At a predetermined position where the laser beam passes through the mirrors 3 and 4 and passes therethrough, a slit light generating cylindrical lens 5 having a size covering the length and width thereof is arranged. Since the generatrix 5b of this cylindrical lens is orthogonal to the generatrix direction of the cylindrical integrator, the laser beam is condensed so that it is focused by the cylindrical lens 5 to the focal point F5 in the direction extending in the generatrix direction of the cylindrical integrator. In the direction orthogonal to the integrator bus direction,
Since the laser beams incident on the cylindrical lens 5 are superposed and condensed on the same plane, a long focal line F is formed substantially at the focal point F5 of the cylindrical lens 5.

Here, the ratio between the width of each element (lens surface 2a) of the cylindrical integrator and the focal length thereof is the distance between the slit length to be generated and the focal position F2 of the cylindrical integrator and the focal position F5 of the slit light producing cylindrical lens. The ratio is almost the same. Therefore, this focal line is formed by overlapping the laser beams divided by the cylindrical integrator 2 at substantially the same position, and has a uniform power distribution P1 in the longitudinal direction and a slit-shaped power distribution P2 in the width direction. Becomes The width of this slit light can be made as sharp as about 0.3 mm by appropriately selecting the position and focal length of the cylindrical integrator 2.

The surface of the substance 6 is intermittently irradiated with the slit light of the excimer laser thus obtained in a pulsed manner,
By moving the substance 6 in synchronization with the pulse period, it is possible to apply uniform energy to the surface of the substance 6 and realize surface modification. In this embodiment, it is possible to arrange a cylindrical mirror instead of the cylindrical lens 5.

4 to 6 show another embodiment of the present invention. In each figure, the same parts as those in FIG. 2 are designated by the same reference numerals, and detailed description thereof will be omitted.

In the embodiment shown in FIG. 4, a cylindrical lens 7 having a generatrix 7b in a direction parallel to the generatrix 2b is arranged behind the cylindrical integrator 2. This cylindrical lens 7 has its focal point F7 substantially aligned with the slit light center so that the laser beam that has passed through each lens surface 2a of the cylindrical integrator 2 can be aligned on the material surface, and the slit light is superposed in the longitudinal direction. 4A, the power distribution P3 can have a sharp rise and fall in the longitudinal direction as shown in FIG. This allows the energy of the excimer laser to be used more effectively. This cylindrical lens 7 can also be arranged in front of the cylindrical integrator 2.

In the embodiment shown in FIG. 5, another cylindrical integrator 8 is arranged behind the cylindrical integrator 2. The busbar 8b of the cylindrical integrator 8 is orthogonal to the busbar 2b of the cylindrical integrator 2. The focus F8 of the cylindrical integrator 8 and the front focus F5 ′ of the slit light generation cylindrical lens 5 are arranged so as to substantially coincide with each other, and the laser beam passing through each element is overlapped in the width direction on the irradiation surface. Done. This makes it possible to generate uniform slit light having a trapezoidal energy distribution P4 in the width direction. This cylindrical integrator 8 can also be arranged in front of the cylindrical integrator 2.

In the embodiment shown in FIG. 6, the cylindrical lens 7 shown in FIG. 4 is added to the optical system shown in FIG.
Similar to FIG. 4, the generatrix 7b of the cylindrical lens 7 is arranged parallel to the generatrix 2b of the cylindrical integrator. In this embodiment, an efficient slit light irradiation optical system having a trapezoidal power distribution P5, P6 with a sharp edge in the focal line F direction and the width direction is realized.

[0020]

As is apparent from the above description, according to the present invention, the laser light divided into the strip shape by the cylindrical integrator and condensed is a cylindrical optical element having a generatrix orthogonal to the generatrix direction of the cylindrical integrator. Due to this, in the generatrix direction of the cylindrical integrator, the light is condensed so as to be constricted to one point, and in the generatrix direction of the cylindrical optical element, the lights are superimposed and condensed on the same plane, so that it is uniform in the longitudinal direction and the width direction. Slit light having a power distribution is formed, and a slit light irradiation optical system capable of speeding up is realized.

[Brief description of drawings]

FIG. 1 is an optical layout diagram showing an optical layout of a slit light irradiation optical system of the present invention.

2A is a top view showing the principle configuration of the slit light irradiation optical system in FIG. 1, and FIG. 2B is a side view thereof.

FIG. 3 is an explanatory diagram showing power distributions of laser light in directions orthogonal to each other.

FIG. 4A is a top view showing a principle configuration of another embodiment of the slit light irradiation optical system of the present invention, and FIG. 4B is a side view thereof.

5A is a top view showing the principle configuration of still another embodiment of the slit light irradiation optical system of the present invention, and FIG. 5B is a side view thereof.

6A is a top view showing the principle configuration of still another embodiment of the slit light irradiation optical system of the present invention, and FIG. 6B is a side view thereof.

[Explanation of symbols]

 1 Laser light 2 Cylindrical integrator 5 Cylindrical lens 6 Material surface 7 Cylindrical lens 8 Cylindrical integrator

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kazunori Ando 1-8 Nakase, Nakase, Mihama-ku, Chiba, Chiba Seiko Electronics Co., Ltd.

Claims (5)

[Claims] 1. A cylindrical integrator having a strip-shaped cylindrical lens surface, which splits and condenses incident laser light at each cylindrical lens surface and then superimposes the laser light, and a generatrix orthogonal to a generatrix direction of the cylindrical integrator. A slit light irradiation optical system comprising: a cylindrical optical element that collects laser light from the cylindrical integrator and generates slit light in a direction orthogonal to the generatrix direction of the cylindrical integrator. 2. The slit light irradiation optical system according to claim 1, wherein a cylindrical lens having a generatrix parallel to a generatrix direction of the cylindrical integrator is arranged in the vicinity of the front or the rear of the cylindrical integrator. 3. Another cylindrical integrator having a busbar in the direction orthogonal to the busbar direction of the cylindrical integrator is arranged near the front or rear of the cylindrical integrator.
The slit light irradiation optical system described in. 4. The slit light irradiation optics according to claim 3, wherein a cylindrical lens having a generatrix in a direction orthogonal to a generatrix direction of the other cylindrical integrator is arranged in the vicinity of the rear of the other cylindrical integrator. system. 5. An optical axis of the cylindrical integrator is bent by a plurality of mirrors, and a cylindrical optical element is arranged on the optical axis such that the optical axis intersects the optical axis. Item 1. The slit light irradiation optical system according to Item 1.