JPH07299576A - Optical machining equipment - Google Patents

Abstract

PURPOSE:To suppress adhesion of sputtered particle and reaction product by providing the protective material of specific material in the cylindrical body arranged with a combined lens of beam forming optical system and the cylindrical body arranged with a combined lens of image forming optical system. CONSTITUTION:When a scattered beam by a transmitting lens 41 and a reflecting beam on the surface of an object 10 to be machined are made incident an a protective material 43 made of synthetic quartz or optical glass, about 92% is passed the protective material 43, about the remaining 8% is reflected/ absorbed by the incidence surface of protective material 43. Also, a cylindrical body 42 is irradiated with the ultraviolet laser beam permeated through protective material 43 to be sputtered so as to generate a sputtered particle and its reaction product of metal or plastic, it is impeded by the protective material 43 so as not to be stuck or vapor deposited to the combined lens 41. By this method, contamination of the combined lens 41 is greatly suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention irradiates an ultraviolet laser beam onto a mask having a pattern consisting of minute light passage holes and light-shielding portions, and transfers the pattern onto the surface of a workpiece to carry out drilling. The present invention relates to an optical processing device.

[0002]

2. Description of the Related Art FIG.
Laser processing, No. RTM-92-38, 1992 1
It is a block diagram which shows the optical system of the conventional optical processing apparatus published on pages 37-41 in January. In the figure, 1 is an excimer laser oscillator that oscillates an ultraviolet laser beam and outputs the laser beam, and 2 is a beam expander of a beam shaping optical system that expands and shapes the laser beam from the excimer laser oscillator 1 and a concave lens 2a. The convex lens 2b is a combination lens. Reference numeral 3 is a mask formed of a thin film on the surface of a translucent synthetic quartz plate or optical glass plate and having a predetermined light passage hole (diameter of about 30 μm) and a light shielding portion, and 4 is a mask. A transfer lens 10 of an image forming optical system for forming an image of a laser beam is a workpiece for transferring a pattern of the mask 4 and performing a drilling process.

The conventional optical processing apparatus is constructed as described above, and the laser beam output from the excimer laser oscillator 1 is expanded and shaped by the beam expander 2 and applied to the mask 3. The laser beam that has passed through the passage hole of the mask 3 is imaged on the surface of the workpiece 10 by the transfer lens 4, and the patterning of the mask 3 is transferred by the photochemical reaction to perform the drilling process. Fine drilling can be done precisely at once without heat damage.

FIG. 6 is a block diagram showing an optical system of a conventional optical processing apparatus different from the above. In the figure, 1, 4,
Reference numeral 10 is the same as that described in FIG. 5, and reference numeral 6 is a beam contractor of a beam shaping optical system for reducing and shaping the laser beam from the excimer laser oscillator 1 and is composed of a combination lens of a convex lens 6a and a concave lens 6b. Reference numeral 7 is a bend mirror for changing the direction of the laser beam shaped by the beam contractor 6. Reference numeral 8 is a surface of a transparent synthetic quartz plate or an optical glass plate, which has fine light passage holes (diameter of about 20 μm) and high reflectivity. A mask in which a predetermined pattern including a light shielding portion is formed of a thin film, and 9 is a high reflection mirror which repeatedly re-reflects the laser beam reflected by the light shielding portion of the mask 8.

In this conventional optical processing apparatus, the laser beam output from the excimer laser oscillator 1 is reduced by the beam contractor 6 and shaped into a sheet, and the bend mirror 7 changes its direction and irradiates the mask 8. Since the area of the mask 8 occupied by the passage holes is very small compared to the entire area,
The laser beam reflected by the light-shielding portion of the mask 8 is repeatedly reflected again between the high-reflection mirror 9 and the laser beam for effective use. The laser beam passing through the passage hole of the mask 8 is transferred to the transfer lens 4
Then, an image is formed on the surface of the object to be processed 10, and the patterning of the mask 8 is transferred by the photochemical reaction to perform the drilling process.

[0006]

Since the conventional optical processing apparatus is constructed as described above and the beam expander 2, the transfer lens 4 and the beam contractor 6 are all combined lenses, the laser beam is incident thereon. Then, scattered light cannot be avoided, and reflected light is also generated on the masks 3 and 8 and the workpiece 10. When this scattered light or reflected light irradiates and sputters a cylindrical body (not shown) equipped with a combination lens, sputtered particles of metal or plastic forming the cylindrical body and reaction products thereof are generated, which is the combination lens. However, there is a problem to be solved that the compound lens is contaminated and the optical characteristics thereof are deteriorated, and the workpiece 10 cannot be sufficiently drilled.

The present invention has been made in order to solve the above problems, and even if the scattered light or reflected light of the laser beam irradiates the cylindrical bodies of the beam expander, the transfer lens and the beam contractor. It is an object of the present invention to obtain an optical processing apparatus which suppresses the sputtered particles and reaction products from adhering to a combination lens or chemical vapor deposition and does not deteriorate the optical characteristics.

[0008]

An optical processing apparatus according to the present invention enlarges or reduces a laser beam of an ultraviolet laser beam by a beam shaping optical system including a combination lens to shape a minute light passage hole and a light shielding portion. The laser beam that has passed through the passage hole by irradiating the mask with a predetermined pattern consisting of and is imaged on the surface of the workpiece by the imaging optical system consisting of a combination lens, and the pattern is transferred by the photochemical reaction. In which the beam shaping optics combination lens is mounted and the imaging optics combination lens is mounted, the protection is made of synthetic quartz or optical glass in which the optical path of the laser beam is hollow. The member is internally provided.

A light absorbing member that absorbs ultraviolet laser light and has an opening corresponding to the cross section of the laser beam emitted from the beam shaping optical system is attached to the end surface of the cylindrical body facing the mask of the beam shaping optical system, A light absorbing member that absorbs ultraviolet laser light and has an opening corresponding to the cross section of the laser beam emitted from the imaging optical system is attached to the end surface of the cylindrical body facing the workpiece of the imaging optical system.

An antireflection film is applied to the surface on the optical path side of a protective member made of synthetic quartz or an optical lens.

The surface of the light absorbing member is made into a minute uneven surface.

A triangular groove having an obtuse angle is provided on the surface of the light absorbing member.

The light absorbing member is provided with a cavity for attenuating and absorbing the ultraviolet laser light reflected on the surface of the workpiece.

A laser beam of an ultraviolet laser beam is shaped by enlarging or reducing it by a beam shaping optical system including a combination lens, and irradiating a mask having a predetermined pattern of minute light passage holes and a light shielding portion and passing therethrough. A combination lens of beam shaping optical system in an optical processing device that forms a laser beam that has passed through a hole on the surface of a workpiece with an imaging optical system consisting of a combination lens and transfers a pattern by a photochemical reaction The cylindrical body having the lens and the cylindrical body having the combination lens of the imaging optical system are made of synthetic quartz or optical glass, and the outer peripheral surfaces of both cylindrical bodies absorb the ultraviolet laser light. Cover with.

[0015]

The protective member in the present invention produces scattered particles and reaction products even when the scattered light and the reflected light of the laser beam irradiate the cylindrical body of the beam shaping optical system or the cylindrical body of the imaging optical system for sputtering. It suppresses adhesion and chemical vapor deposition to the combination lens of the beam shaping optical system and the combination lens of the imaging optical system.

The light absorbing member provided on the end surface of the cylindrical body of the beam shaping optical system absorbs the ultraviolet laser light reflected by the light shielding portion of the mask, and the light absorbing member provided on the end surface of the cylindrical body of the imaging optical system. Absorbs the ultraviolet laser light reflected on the surface of the workpiece.

The antireflection film allows scattered light and reflected light of the laser beam incident on the protective member to pass through with almost no reflection.

The uneven surface of the light absorbing member enhances the effect of absorbing the ultraviolet laser light reflected on the surface of the workpiece.

The triangular groove on the surface of the light absorbing member enhances the absorption effect of the ultraviolet laser light reflected on the surface of the workpiece.

The cavity of the light absorbing member attenuates and absorbs the ultraviolet laser light reflected on the surface of the workpiece.

The cylindrical body of the beam shaping optical system and the cylindrical body of the imaging optical system are made of synthetic quartz or optical glass, and their outer peripheral surfaces are covered with a light absorbing member. Therefore, scattered light and reflected light of the laser beam are different from each other. Even if the light is incident on the cylindrical body and is sputtered, almost no sputtered particles or reaction products are generated, and the light absorbing member absorbs scattered light and reflected light transmitted through each cylindrical body.

[0022]

【Example】

Example 1. 1 is a sectional view showing an image forming optical system according to Embodiment 1 of the present invention. In the figure, 10 is a conventional technique and FIG.
41 is a combination lens composed of a convex lens and a concave lens, 42 is a cylindrical body in which the combination lens 41 is mounted, 43 is a synthetic quartz or optical lens provided in the cylindrical body 42 It is a member.

Although not shown, the optical system of the first embodiment is similar to that of the conventional optical processing apparatus shown in FIG.
A laser beam output from the excimer laser oscillator 1 is expanded and shaped by a beam shaping optical system and irradiated on a mask. The laser beam that has passed through the passage hole of the mask is imaged on the surface of the workpiece 10 by the imaging optical system, and the hole patterning is performed by transferring the pattern of the mask by the photochemical reaction. By the way, this imaging optical system is configured as described above, and the scattered light from the combination lens 41 and the reflected light on the surface of the workpiece 10 (these examples are shown by the broken line in FIG. 1) are made of synthetic quartz or When entering the protective member 43 made of optical glass, about 92
% Passes through the protective member 43, and the remaining approximately 8% is the protective member 4.
It is reflected and absorbed by the incident surface of 3. Since the protective member 43 absorbs a small amount of the ultraviolet laser light, the synthetic quartz or the optical glass constituting the protective member 43 hardly produces sputtered particles. Further, the ultraviolet laser light transmitted through the protective member 43 irradiates the cylindrical body 42 and is sputtered to generate sputtered particles of metal or plastic constituting the cylindrical body 42 and a reaction product thereof, but these are blocked by the protective member 43. As a result, the compound lens 41 hardly adheres to the compound lens 41 or is chemically vapor-deposited, and the contamination of the compound lens 41 is greatly suppressed. Since the beam shaping optical system also has a protective member made of synthetic quartz or optical glass internally provided in a cylindrical body equipped with a combination lens, the scattered particles by the combination lens and the sputtered particles by the reflected light at the light shielding portion of the mask or its It has the same effect on the reaction product.

Example 2. FIG. 2 is a sectional view showing an image forming optical system according to a second embodiment of the present invention, and reference numerals 10, 41 to 43 have been described in the first embodiment. Reference numeral 45 is a plate-shaped light absorbing member mounted on the end surface of the tubular body 42 facing the workpiece 10, and 45a is an opening of the light absorbing member 45. As described above, the imaging optical system according to the second embodiment absorbs the ultraviolet laser light on the end surface of the cylindrical body 42 facing the workpiece 10, and the opening corresponding to the cross section of the laser beam emitted from the imaging optical system. The light absorbing member 45 having the portion 45a is attached. As a result, the ultraviolet laser light reflected on the surface of the workpiece 10 and incident on the outside of the opening 45a is absorbed, and therefore the contamination of the combination lens 41 due to the ultraviolet laser light is further reduced. Although not shown, the beam shaping optical system also absorbs ultraviolet laser light on the end surface of the cylindrical body facing the mask, and has a light absorption having an opening corresponding to the cross section of the laser beam emitted from this beam shaping optical system. Since the member is mounted and reflected by the light shielding portion of the mask to absorb the ultraviolet laser light incident on the outside of the opening, the same effect can be obtained.

Example 3. When an antireflection film is vapor-deposited on the optical path side surface of the protective member made of synthetic quartz or optical glass provided in each cylindrical body of the beam shaping optical system and the imaging optical system in the first and second embodiments, the combined lens is obtained. Scattered light,
Most of the light reflected by the light-shielding portion of the mask and the surface of the additive passes through the protective member, and only a small amount of light is reflected by the surface of the protective member, making it difficult to cover with a cylindrical protective member. It is possible to prevent the portion from being irradiated with the scattered light and the reflected light and being sputtered.

Example 4. In the second embodiment, the surfaces of the light absorbing members mounted on the end surface of the cylindrical body facing the mask of the beam shaping optical system and the end surface of the cylindrical body facing the workpiece of the imaging optical system are made into minute irregularities. Alternatively, by providing a triangular groove having an obtuse apex angle to increase the surface area, it is possible to enhance the effect of absorbing the ultraviolet laser light reflected by the light-shielding portion of the mask and the surface of the workpiece.

Example 5. FIG. 3 is a sectional view showing an image forming optical system according to a fifth embodiment of the present invention, and 10, 41 to 43 have been described in the first embodiment. Reference numeral 46 is a light absorbing member mounted on the end surface of the tubular body 42 facing the workpiece 10, 46a is an opening of the light absorbing member 46, and 46b is a cavity of the light absorbing member 46. In the image forming optical system of the fifth embodiment, the light absorbing member 46 that absorbs the ultraviolet laser light and has the opening 46a and the cavity 46b is attached to the end surface of the cylindrical body 42 facing the workpiece 10 as described above. As a result, the ultraviolet laser light reflected on the surface of the workpiece 10 and incident on the outside of the opening 46a is absorbed, and the ultraviolet laser light incident on the cavity 46b is attenuated and absorbed. The light absorbing member 46 can further enhance the effect of absorbing the ultraviolet laser light reflected on the surface of the workpiece. Although not shown, the beam shaping optical system also absorbs the ultraviolet laser light on the end surface of the cylindrical body facing the mask, and shields the opening and the mask corresponding to the cross section of the laser beam emitted from the beam shaping optical system. Since the cavity portion that attenuates and absorbs the ultraviolet laser light reflected by the section is provided, the same effect can be obtained.

Example 6. FIG. 4 is a sectional view showing an image forming optical system according to a sixth embodiment of the present invention, and reference numerals 10, 41 have been described in the first embodiment. Reference numeral 142 denotes a cylindrical body to which the combination lens 41 is attached, which is made of synthetic quartz or optical glass. A light absorbing member 143 covers the outer peripheral surface of the cylindrical body 142 and absorbs the ultraviolet laser light. This imaging optical system is configured as described above, and the scattered light by the combination lens 41 and the reflected light on the surface of the workpiece 10 (these examples are shown by the broken line in FIG. 4) are synthetic quartz or optical glass. Tubular body 142 made of
When incident on, about 92% is transmitted, and the remaining about 8% is reflected and absorbed by the incident surface. Since the ultraviolet laser light absorbed by the cylindrical body 142 is very small, almost no sputtered particles of synthetic quartz or optical glass are produced. In addition, the tubular body 142
The ultraviolet laser light that has passed through is irradiated onto the light absorbing member 143 and is absorbed. Therefore, a larger effect than that of the first embodiment can be expected. Although not shown, the beam shaping optical system has the same effect as the imaging optical system because the cylindrical body having the combination lens mounted thereon is made of synthetic quartz or optical glass.

[0029]

As described above, the present invention has the following effects.

A laser beam of an ultraviolet laser beam is shaped by enlarging or reducing it by a beam shaping optical system including a combination lens, irradiating a mask having a predetermined pattern of passing holes for fine light and a light shielding portion, and passing it. A combination lens of beam shaping optical system in an optical processing device that forms a laser beam that has passed through a hole on the surface of a workpiece with an imaging optical system consisting of a combination lens and transfers a pattern by a photochemical reaction Since a protective member made of synthetic quartz or optical glass in which the optical path of the laser beam is hollow is provided inside the cylindrical body equipped with the combination of the cylindrical body equipped with and the imaging optical system, scattered light of the laser beam And reflected light enters the protective member and irradiates each cylindrical body for sputtering, the sputtered particles and reaction products are attached to the combination lens. Is suppressed to or chemical vapor deposition,
Its optical characteristics do not deteriorate.

A light absorbing member that absorbs ultraviolet laser light and has an opening corresponding to the cross section of the laser beam emitted from the beam shaping optical system is attached to the end surface of the cylindrical body facing the mask of the beam shaping optical system, Since the ultraviolet laser beam is absorbed on the end surface of the cylindrical body facing the workpiece of the imaging optical system, and a light absorbing member having an opening corresponding to the cross section of the laser beam emitted from the imaging optical system is attached, The ultraviolet laser light reflected by the light-shielding portion of the mask and the surface of the workpiece is absorbed to suppress the generation of sputtered particles and reaction products from each cylindrical body.

Since an antireflection film is coated on the surface of the protective member made of synthetic quartz or an optical lens on the optical path side, the scattered light and the reflected light of the laser beam irradiate the portion of each cylindrical body which cannot be covered by the protective member. As a result, sputtering is suppressed, and the generation of sputtered particles and reaction products is almost eliminated.

Since the surface of the light absorbing member is made into a minute uneven surface, the absorption effect of the ultraviolet laser light reflected by the light shielding portion of the mask and the surface of the workpiece is enhanced, and the sputtered particles and reaction generated from each cylindrical body are generated. Generation of objects is suppressed.

Since a triangular groove having an obtuse angle is provided on the surface of the light absorbing member, the effect of absorbing the ultraviolet laser light reflected by the light shielding portion of the mask and the surface of the workpiece is enhanced, and sputtering from each cylindrical body is performed. Generation of particles and reaction products is suppressed.

Since the optical processing member is provided with a cavity for attenuating and absorbing the ultraviolet laser light reflected on the surface of the workpiece,
The effect of absorbing the ultraviolet laser light reflected by the light-shielding portion of the mask and the surface of the workpiece is further enhanced, and the generation of sputtered particles and reaction products from each cylindrical body is suppressed.

A laser beam of an ultraviolet laser beam is enlarged or reduced by a beam shaping optical system composed of a combination lens to be shaped, and is irradiated onto a mask having a predetermined pattern of minute light passage holes and a light shielding portion to pass therethrough. A combination lens of beam shaping optical system in an optical processing device that forms a laser beam that has passed through a hole on the surface of a workpiece with an imaging optical system consisting of a combination lens and transfers a pattern by a photochemical reaction The cylindrical body having the lens and the cylindrical body having the combination lens of the imaging optical system are made of synthetic quartz or an optical lens, and the outer peripheral surfaces of both cylindrical bodies absorb the ultraviolet laser light. Since it is covered with, even if scattered light or reflected light of the laser beam enters each cylindrical body and irradiates the light absorbing member, sputtered particles of synthetic quartz or optical glass are generated. Almost no optical characteristics of the lens combination is absorbed by the light absorbing member is not reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an image forming optical system according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing an image forming optical system according to Example 2 of the present invention.

FIG. 3 is a sectional view showing an image forming optical system according to Example 5 of the present invention.

FIG. 4 is a sectional view showing an image forming optical system according to Example 6 of the present invention.

FIG. 5 is a configuration diagram showing an optical system of a conventional optical processing apparatus.

6 is a configuration diagram showing an optical system of a conventional optical processing apparatus different from that in FIG.

[Explanation of symbols]

 10 Workpiece 41 Combined lens 42 Cylindrical body 43 Protective member 45 Light absorption member 45a Opening 46 Light absorption member 46a Opening 46b Cavity 142 Cylindrical body 143 Light absorption member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuyuki Omoto 8-1-1 Tsukaguchihonmachi, Amagasaki City Mitsubishi Electric Corporation

Claims (7)

[Claims] 1. A laser beam of an ultraviolet laser beam is shaped by enlarging or reducing it by a beam shaping optical system including a combination lens, and irradiating a mask having a predetermined pattern including a minute light passage hole and a light shielding portion. The laser beam that has passed through the passage hole is imaged on the surface of the workpiece by an imaging optical system including a combination lens, and the pattern is transferred by a photochemical reaction. A protective member made of synthetic quartz or optical glass having a hollow optical path of the laser beam is provided on each of the cylindrical body having the combination lens of the shaping optical system and the cylindrical body having the combination lens of the imaging optical system. An optical processing device characterized by being installed internally. 2. A light absorbing member that absorbs ultraviolet laser light and has an opening corresponding to a cross section of a laser beam emitted from the beam shaping optical system on an end surface of a cylindrical body facing a mask of the beam shaping optical system. Light absorption having the opening corresponding to the cross section of the laser beam that is mounted and that absorbs the ultraviolet laser light on the end surface of the cylindrical body that faces the workpiece of the imaging optical system and that exits the imaging optical system. The optical processing device according to claim 1, wherein a member is attached. 3. The optical processing device according to claim 1, wherein an antireflection film is coated on the surface on the optical path side of the protective member made of synthetic quartz or optical glass. 4. The optical processing device according to claim 2, wherein the surface of the light absorbing member is formed into a minute uneven surface. 5. The optical processing device according to claim 2, wherein a triangular groove having an obtuse angle is provided on the surface of the light absorbing member. 6. The optical processing apparatus according to claim 2, wherein the light absorbing member is provided with a cavity that attenuates and absorbs the ultraviolet laser light reflected on the surface of the workpiece. 7. A laser beam of ultraviolet laser light is shaped by enlarging or reducing it by a beam shaping optical system including a combination lens, and irradiating a mask having a predetermined pattern including a minute light passage hole and a light shielding portion. The laser beam that has passed through the passage hole is imaged on the surface of the workpiece by an imaging optical system including a combination lens, and the pattern is transferred by a photochemical reaction. The cylindrical body with the combination lens of the shaping optical system and the cylindrical body with the combination lens of the imaging optical system made of synthetic quartz or an optical lens, and the outer peripheral surfaces of the both cylindrical bodies. An optical processing device, characterized in that the above is covered with a light absorbing member that absorbs the ultraviolet laser light.