JP2001284294A - Laser beam stimulated etching processing device, wherein near field optical probe is used, and processing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser beam stimulation etching processing device using near field light, whose processing efficiency and feasibility are raised, and to provide its processing method. SOLUTION: An optical stimulation etching processing device 10A, which performs etching for a work piece 240 by performing optical stimulation for reaction gas inside a reaction bath 260, is constituted of a plurality of near field optical probes 100A to 100C each of which enables position control independently, a laser oscillator 210 which becomes a light source of near field light which is generated by each of the near filed optical probes 100A to 100C, and converging lenses 30A to 30C which converge the laser beam of the laser oscillator 210 through a window 262 provided to the reaction bath 260 and inject it to each of the near field optical probes 100A to 100C. It is good to use a stage device, which controls one to three-dimensional positions of the near field optical probes 100A to 100C as a means for making each of the near field optical probes 100A to 100C position controllable independently.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser-excited etching apparatus and a processing method used for manufacturing various devices such as optical elements, micromachines, optical communication devices, and integrated circuits. The present invention relates to a laser beam excitation etching apparatus using a plurality of near-field probes for generating near-field light and a processing method thereof.

[0002]

2. Description of the Related Art Microfabrication apparatuses such as etching apparatuses for manufacturing devices such as integrated circuits using plasma, ion beams, X-rays, laser beams, and the like have been put to practical use.
In these conventional etching processing apparatuses, in the processing step including a step of condensing the laser beam with a condenser lens, there is a problem of a diffraction limit of about half a wavelength of the laser beam, and the processing accuracy is a fundamental limit. Therefore, it is extremely difficult to dramatically improve the processing accuracy.

For example, when an excimer laser oscillator is used as a light source, the wavelength of an ultraviolet laser oscillated by the excimer laser oscillator is about 150 to 300 nm.
The processing accuracy of about half a wavelength is the limit.

[0004] On the other hand, the use of X-rays improves the processing accuracy, but at present it is unclear to mass-produce the light source. Further, in the fine processing using an ion beam or an electron beam, processing on the order of nanometers has been realized, but there is a problem that a workpiece to be processed is greatly damaged and a residual deteriorated layer remains.

[0005] Accordingly, an etching apparatus using a near-field optical probe has been proposed in which the processing accuracy is remarkably improved by a laser beam excitation reaction that cannot form a damaged layer. An etching apparatus using the conventional near-field optical probe will be described with reference to FIGS. 5 and 6. In order to facilitate understanding of the conventional etching apparatus,
Prior to the description of this conventional etching apparatus, the characteristics of near-field light and a near-field light probe for generating near-field light will be supplementarily described with reference to FIGS.

First, the principle of generation of near-field light and characteristics of near-field light will be described with reference to FIG. As described above, if it is limited to photoexcitation etching using laser light, as long as visible light, ultraviolet light or extreme ultraviolet light is condensed by a condensing lens and used as a reactive radical generating means,
The processing accuracy of about several hundred nm is the limit due to the diffraction limit.

However, since near-field light is light that does not propagate in space, it does not exhibit diffraction properties and does not have the problem of the diffraction limit. In addition, the processing accuracy of the etching depends on the size of the opening of the near-field optical probe that generates the near-field light, which will be described later. Therefore, by making this opening as small as possible, the processing is theoretically infinite. Accuracy can be improved.

[0008] If the laser light is compared to a water stream that vigorously flows out of the thin tube, the near-field light is compared to a water droplet remaining at the opening of the thin tube. The principle of generation of this near-field light will be described with reference to FIG.

As shown in FIG. 3, it is assumed that incident light is incident on a virtual sphere A having a diameter sufficiently smaller than the wavelength of the incident light. At this time, most of the incident light is transmitted, reflected, and scattered through the sphere A and propagates through the space. However, at the same time as the propagating light, the electrons in the atoms and molecules are excited by the light incident on the inside of the sphere A, and countless small oscillating electric dipoles are formed.

[0010] These electric dipoles are confined within the sphere A,
Due to the constraint of having a generally spherical surface, each of them is appropriately redirected by the electrical interaction between these electric dipoles so that the entire sphere A responds to incident light with a large Arrange them to be electric dipoles.

Light is an electromagnetic field oscillating at a very high frequency, and some of the lines of electric force near the surface of the sphere A and representing the interaction between the oscillating electric dipoles fly out of the surface of the sphere A. The near-field light is obtained by adding all the lines of electric force that have jumped out in this manner. However, the end of each line of electric force is connected to an internal electric dipole and is near the surface of the sphere A, and the energy of the near-field light decreases rapidly as the distance from the surface of the sphere A increases. For example, a position where the energy value on the surface becomes e ⁻² (e = 2.771828...) Is a position separated by a distance equal to the diameter of the sphere A. Therefore, it can be said that the near-field light is a thin film of light oozing on the surface of the sphere A.

That is, the energy of the near-field light propagates only along the surface of the sphere A, and does not propagate in a direction away from the surface of the sphere A. That is, it is called “near-field light” because it is light in which energy is concentrated near the surface of the sphere A.

By the way, the near-field light is light that propagates only on the surface of the sphere A, does not interact even if a sample is placed far from the sphere A, and cannot be measured even if a photodetector is placed.
Therefore, in order to measure the near-field light, a second sphere (having the same diameter as the sphere A) is omitted from the surface of the sphere A within a distance of about the diameter at which the energy of the near-field light is concentrated, although not shown. The near-field light is scattered by the second sphere, and the scattered light is detected to measure the near-field light.

On the other hand, if the near-field light is strongly disturbed so that the distribution of the electric dipoles of the second sphere changes, a part of the second sphere can be dented or its structure or composition can be changed. It is. That is, a near-field light is generated in an opening formed at the tip of a near-field light probe described later, and the near-field light is brought close to a workpiece, which is a workpiece, so that the surface thereof is depressed to change the structure or change the near-field light. Utilizing this to excite a reactive gas to generate reactive radicals, indicating that etching is possible.

Next, a near-field light probe for generating near-field light will be described with reference to FIG. FIG. 4 is a vertical sectional side view showing the structure of the near-field optical probe 100. FIG.
As shown in FIG. 2, the near-field optical probe 100 includes an optical fiber 110 for transmitting light for generating near-field light,
Opening 120 for generating near-field light, optical fiber 1
The optical waveguide section 130 achieves high coupling efficiency between the optical waveguide 10 and the opening 120. As shown in FIG.
The opening 120 is formed at the tip of the near-field optical probe 100, while the periphery 130a of the optical waveguide 130 is covered with a metal film having a high light reflectance such as aluminum.

In the above configuration, the near-field light is a light such as a laser light from a laser oscillator (not shown).
The light is generated in the opening 120 via the optical fiber 110 and the optical waveguide unit 130. As described above, the near-field light has no diffraction limit because it is light that does not propagate through space, and interacts with the near-field light generated in the opening 120 directly with surface molecules and atoms of the workpiece. The processing accuracy is almost the same as the diameter of the opening 120. Therefore, in principle, by reducing the diameter of the opening 120, the processing accuracy can be improved without limit. In recent years, the near-field optical probe 100 in which the opening 120 has a diameter of about 2 to 3 nm to several μm order has been manufactured.

Based on the above preliminary description, FIG. 5 shows a conventional laser-excited etching apparatus using a near-field optical probe (hereinafter, may be simply referred to as an "etching apparatus"). This will be described with reference to FIG. FIG. 5 is a side view showing a basic configuration of a conventional etching apparatus 200. FIG. 6 is an enlarged perspective view of a partially cut-away view for explaining the etching process by the near-field light generated in the opening 120 of the near-field light probe 100.

As shown in FIG. 5, a conventional etching apparatus 200 mainly includes a laser oscillator 210,
A near-field optical probe 100 and a condenser lens 230 for condensing laser light L from a laser oscillator 210 and making the laser light L incident on the near-field optical probe 100 are provided.

In FIG. 5, reference numeral 240 denotes a workpiece which is a workpiece, 250 denotes a stage device for moving the workpiece 240 three-dimensionally, 260 denotes a reaction tank, 270 denotes an exhaust tube, and 272 collects a laser beam L. This is a reflection mirror that reflects light to the optical lens 230. In the reaction tank 260, a process window 262 made of quartz glass through which the laser light L condensed by the condenser lens 230 is transmitted, a supply port 264 for supplying a reaction gas, and atoms and molecules of the work 240 and the reaction gas are formed. Exhaust port 26 for exhausting volatile substances generated by the reaction
6 are provided.

The near-field optical probe 100 and the work 240
The stage device 250 is accommodated in a reaction tank 260, and the reaction gas is supplied to the reaction gas supply port 26 in the reaction tank 260.
The reaction gas is supplied from 4 as needed and filled with a reaction gas at a substantially constant pressure.

An on-line detector 280 detects the distance between the work 240 and the opening 120 of the near-field light probe 100. This online detector 280
A condenser lens for detector 28 is provided with a condenser lens for detector 284, a photodetector 286, a laser oscillator for measurement 287, a beam splitter 290, and a dichroic mirror 292.
4, the photodetector 286 and the measuring laser oscillator 287 are installed outside the reaction tank 260.

The measuring laser beam L 'oscillated from the measuring laser oscillator 287 is split by the beam splitter 290 in the direction of the dichroic mirror 292 and the photodetector 286, and the dichroic mirror 292 and the light pumping laser beam L
And the opening 12 of the near-field optical probe 100
Zero generates near-field light. By detecting the intensity of scattered light generated by the interaction between the near-field light formed by the measurement laser light L ′ and the work 240, the work 240
And the distance between the opening 120 and the near-field optical probe 100 are detected.

The basic operation of the conventional laser-light-excited etching apparatus 200 using the near-field optical probe will be described with reference to FIGS. 5 and 6. FIG. Laser oscillator 21
The laser light L oscillated from 0 enters the near-field optical probe 100 via the reflection mirror 272 and the condenser lens 230.

As described above, the laser light L incident on the near-field optical probe 100 is transmitted to the optical fiber 11 shown in FIG.
0, near-field light is generated in the opening 120 via the optical waveguide unit 130.

On the other hand, an opening 120 of the near-field light probe 100 in which near-field light is generated
When the stage device 250 is controlled to approach the vicinity, as shown in FIG. 6, the near-field light K optically excites the reaction gas G near the opening 120 to generate a reaction radical G ′, and the reaction radical G ′ 'Reacts with the atoms / molecules 240a of the work 240 to generate a volatile substance B.

The volatile substance B is supplied to the exhaust tube 270
Tank 26 by a vacuum pump (not shown) connected to
It is discharged outside zero. Thus, the atoms of the work 240
The processing proceeds by the removal of the molecules 240a as volatile substances B, and the surface of the work 240 can be etched into a desired shape.

At this time, as described above, the near-field light is light that does not propagate in space, and the reaction gas is directly excited by the near-field light without using a condenser lens when a reaction radical is generated. Does not exist. In other words, the processing accuracy of the etching process depends on the opening 1 of the near-field optical probe 100.
It is about the same as the diameter of 20. Therefore, the near-field optical probe 1
By making the diameter of the opening 120 of the 00 small,
The processing accuracy of the etching processing apparatus 200 can be dramatically improved. Also, the opening 120 of the near-field optical probe 100 and the work 2
Since the etching process is performed while detecting the distance to the surface 40 online, the processing accuracy can be further improved.

[0028]

The above-described conventional laser-light-excited etching processing apparatus using a near-field optical probe has a configuration using a single near-field optical probe for processing. This is suitable for finely processing a workpiece in a relatively small area.

However, in the etching of the workpiece,
When performing many processes of the same shape in a large area, or
In a large area, there are cases where a large number of processings of different shapes are performed, and if these processings are performed with a single near-field optical probe,
There is a problem that the processing efficiency is poor and it is not suitable for mass production.

The present invention solves the above problems (problems),
It is an object of the present invention to provide a laser beam excitation etching apparatus using near-field light and a processing method thereof, which improve processing efficiency and enhance practicality.

[0031]

According to the first aspect of the present invention, there is provided a laser beam excitation etching apparatus using near-field light, wherein a reaction gas in a reaction tank is optically excited to etch a workpiece. In the photoexcitation processing apparatus for performing the processing, a plurality of controllable near-field optical probes are used as the photoexcitation means.

With this configuration, it is possible to provide an etching apparatus suitable for etching a wide area of a workpiece and improving the processing efficiency.

According to a second aspect of the present invention, there is provided a laser-excited etching apparatus using near-field light, wherein the reaction gas in the reaction tank is optically excited to etch the workpiece. A plurality of near-field light probes whose position can be controlled, a laser oscillator serving as a light source of near-field light generated by each of the near-field light probes, and a laser of the laser oscillator are collected through a window provided in the reaction tank. And a condenser lens that emits light and enters each of the near-field optical probes.

With this configuration, it is possible to perform etching independently with a plurality of near-field optical probes.
Suitable for etching of a wide area of the workpiece and improving the processing efficiency, and when performing a large number of processings of the same shape in a wide area, or even in a case where a large number of processings of different shapes are performed. It is possible to provide an etching apparatus capable of handling and improving practicality.

According to a third aspect of the present invention, in the laser beam excitation etching apparatus using near-field light, one-dimensional to three-dimensional of the near-field optical probe is used as means for controlling the positions of the near-field optical probes independently. The configuration uses a stage device that controls the dynamic position.

With this configuration, it is possible to provide an etching apparatus provided with suitable means for enabling the position control of each near-field optical probe independently.

In the laser beam excitation etching apparatus using near-field light according to a fourth aspect, a fiber probe is used as the near-field light probe.

With this configuration, it is possible to provide a suitable etching apparatus equipped with a near-field light probe having excellent near-field light generation efficiency.

In the laser beam excitation etching apparatus using the near-field optical probe according to the fifth aspect, the metal coating of the optical waveguide portion of the near-field optical probe is made of a high-reflection material such as aluminum, and the vicinity of the opening is formed. Was coated with a corrosion-resistant metal such as gold.

With this configuration, it is possible to prevent light seeping out of the portion other than the opening and to prevent corrosion and deterioration of the opening of the near-field optical probe due to reaction with the reaction gas.

In a laser beam excitation etching apparatus using a near-field optical probe according to a sixth aspect, a light source in the ultraviolet region is used as the light source for light excitation.

With this configuration, when Cl ₂ or a fluorine compound is used as a reaction gas, a laser beam excited etching apparatus equipped with a light source suitable for generating reaction radicals by electronic excitation can be provided.

In a laser beam excitation etching apparatus using a near-field optical probe according to a seventh aspect, a light source in a wavelength region of an infrared region is used as the light source for light excitation.

With this configuration, it is possible to provide a laser beam excited etching apparatus equipped with a light source suitable for generating reaction radicals by resonance excitation of molecules.

In the laser beam excitation etching apparatus using the near-field optical probe according to the present invention, the light source for light excitation is configured to use a light source in a wavelength region excellent in the thermal decomposition and absorption characteristics of the reaction gas. .

With this configuration, it is possible to provide a laser beam excited etching apparatus equipped with a light source suitable for generating reaction radicals when a reaction gas which does not absorb ultraviolet rays, such as SF ₆ , is used.

According to a ninth aspect of the present invention, in the laser beam excited etching apparatus using a near-field optical probe, an on-line detector for detecting a distance between the near-field optical probe and the workpiece is provided.

With this configuration, since the etching can be performed while detecting the distance between the near-field optical probe and the workpiece, the processing accuracy can be further improved.

[0049] In the laser beam excitation etching apparatus using a near-field optical probe according to the present invention, the on-line detector includes a measuring laser oscillator for generating a measuring laser beam for irradiating a workpiece, and a measuring laser oscillator. A near-field light formed by a laser for use, a scattered light generated by interaction with the workpiece, and a photodetector that detects a distance between the opening of the near-field optical probe and the workpiece. And an on-line detector equipped with.

With this configuration, when the laser light from the laser oscillator that optically excites the reaction gas cannot be used for distance measurement, or when it is difficult to use the laser light, an etching apparatus equipped with an effective online distance detector for distance measurement. It can be.

In the laser beam excitation etching apparatus using a near-field light probe according to the eleventh aspect, the on-line detector detects near-field light by detecting scattered light caused by the action of the near-field light and the workpiece. An on-line detector provided with a photodetector for detecting the distance between the probe and the workpiece was used.

With this configuration, the distance can be detected by the scattered light, and a measuring laser oscillator for generating a measuring laser for irradiating the workpiece is not required, so that the configuration of the online detector can be simplified. Thus, it is possible to provide an etching apparatus in which manufacturing costs and maintenance costs are reduced.

In a laser beam excitation etching apparatus using a near-field optical probe according to a twelfth aspect, the measurement laser oscillator is provided in a reaction tank.

With this configuration, the laser oscillator for measurement can be attached near the workpiece and the amount of light reaching the opening of the near-field optical probe can be increased. The accuracy of detecting the distance to the object is improved, and the processing accuracy of the etching process is further improved.

In a laser beam excitation etching apparatus using a near-field optical probe according to a thirteenth aspect, the measurement laser oscillator is provided outside the reaction tank.

With such a configuration, the operation and maintenance of the measuring laser oscillator can be performed outside the reaction tank filled with the reaction gas, and these labors can be reduced.

According to a fourteenth aspect of the present invention, in the laser beam excited etching apparatus using a near-field optical probe, the photodetector is provided in a reaction tank.

With this configuration, since the photodetector can be mounted near the workpiece, the light collection efficiency of the detection light is increased, and the accuracy of detecting the distance between the near-field optical probe and the workpiece is improved. The processing accuracy of the etching processing is further improved.

According to a fifteenth aspect of the present invention, in the laser beam excitation etching apparatus using the near-field optical probe, the photodetector is provided outside the reaction tank.

With this configuration, the operation and maintenance of the photodetector can be performed outside the reaction vessel filled with the reaction gas, and the labor required for the operation can be reduced.

According to the laser beam excitation etching processing method using the near-field optical probe according to claim 16, the laser light excitation etching processing apparatus using the near-field optical probe according to any one of claims 1 to 8 is used. By operating a plurality of near-field optical probes, desired fine processing is performed on the surface of the workpiece.

This makes it possible to provide an etching method suitable for etching a wide area of a workpiece and improving the processing efficiency.

According to a seventeenth aspect of the present invention, there is provided a laser light excited etching processing method using a near-field optical probe, wherein the near-field optical probe is provided with a laser light excited etching apparatus using the near-field optical probe. While detecting the distance between the opening of the field light probe and the workpiece online, a plurality of near-field optical probes were operated to perform desired fine processing on the surface of the workpiece.

This makes it possible to improve the processing efficiency, which is suitable for the etching of a wide area of the workpiece, and to perform online processing while detecting the distance between the opening of the near-field optical probe and the workpiece. Therefore, the processing accuracy can be further improved.

[0065]

BEST MODE FOR CARRYING OUT THE INVENTION A laser-light-excited etching apparatus using a near-field optical probe of the present invention (hereinafter sometimes simply referred to as an "etching apparatus") and a laser-light-excited etching processing using a near-field optical probe. First and second embodiments of the method (hereinafter may be simply referred to as “etching method”) will be described with reference to FIGS. 1 and 2 and FIGS. 5 and 6. In addition,
1 and 2, the same components as those of FIG. 5 are denoted by the same reference numerals, and description thereof will be omitted.

First Embodiment First, a first embodiment of an etching apparatus 10 according to the present invention will be described with reference to FIG. FIG. 1 is a side view showing a basic configuration of an etching apparatus 10A according to the present embodiment.

[0067] Etching apparatus 10A of the present embodiment
As a main configuration, as shown in FIG. 1, a laser oscillator 210, a plurality (three in FIG. 3) of near-field optical probes 100A to 100C, and a laser beam L from the laser oscillator 210 are condensed to form Field light probe 100-100C
Are provided. Note that an array lens such as a fly-eye may be used instead of the condenser lens groups 30A to 30C.

The on-line detector 80 of the present embodiment
Detector condenser lenses 84A-84C, photodetectors 86A-
86C and a measurement laser oscillator 87. Also,
The function of the online detector 80 will be described later. The on-line detector 80 includes a total of five beam splitters 90A to 90E, a dichroic mirror 92, and filters 88A to 88C for blocking light other than the measurement laser light L '.
0 and the opening 12 of the near-field optical probes 100A to 100C
As shown in FIG. 1, a detector condenser lens 84 </ b> A of the online detector 80 detects a distance from the on-line detector 80 </ b> A to 120 </ b> C.
84C, the photodetectors 86A to 86C, and the measurement laser oscillator 87 are installed outside the reaction tank 260.

The two beam splitters 90D, 9
0E is a laser beam L from the processing laser oscillator 210.
Functions as a beam splitter for the light in the wavelength range of
Function of transmitting light in the wavelength range of Also,
The three beam splitters 90A to 90C function as beam splitters for light in the wavelength region of the laser light L 'of the measurement laser oscillator 87. The dichroic mirror 92 has a function of reflecting the light in the wavelength region of the laser light L from the processing laser oscillator 210 and transmits the light in the wavelength region of the laser light L ′ of the measurement laser oscillator 87. Perform the function of

The measuring laser beam L 'oscillated from the measuring laser oscillator 87 is applied to the beam splitters 90A to 90C.
, The beam splitters 90D and 90E, the dichroic mirror 92, and the photodetectors 86A to 86C. Thereafter, the beams are superimposed on the laser beam L for optical excitation by the beam splitters 90D and 90E and the dichroic mirror 92, and are incident on the near-field optical probes 100A to 100C.
The openings 120A-1A are similar to those described in the prior art.
At 20C, near-field light is generated, and interaction with the work 240 generates scattered light.

The scattered light of the measuring laser light L ′ generated by the interaction with the work 240 is transmitted to the openings 120A to 120A.
C reenters the near-field optical probes 100A to 100C, sends the near-field optical probes 100A to 100C backward, transmits through the beam splitters 90D and 90E, and the dichroic mirror 92, and enters the photodetectors 86A to 86C. By detecting the intensity with the photodetectors 86A to 86C, the work 240 and the near-field optical probes 100A to 100A are detected.
The distance from the openings 120A to 120C at 0C is detected.
In addition, if the measurement laser oscillator 87 is, for example, a HeNe laser oscillator, the quantum energy of 633 nm is small, and a suitable measurement laser beam L ′ having no influence on processing is used.
Can occur.

In FIG. 1, similarly to the conventional etching apparatus 200 shown in FIG. 5, reference numeral 250 denotes a stage device for moving a work 240 three-dimensionally, reference numeral 260 denotes a reaction tank,
270 is an exhaust tube. In the reaction tank 260, a process window 262 made of quartz glass through which the laser light L condensed by the condenser lenses 30A to 30C is transmitted, a supply port 264 for supplying a reaction gas,
An exhaust port 266 for exhausting a volatile substance generated by the reaction between the molecule and the reaction gas is provided. Each of the plurality of near-field optical probes 100A to 100C, the work 240, and the stage device 250 are housed in the reaction tank 260,
The reaction gas is supplied from the reaction gas supply port 264 at any time into the inside 60, and is filled with the reaction gas at a substantially constant pressure.

With the above structure, the basic operation and the etching method of the etching apparatus 10A of the present embodiment will be described with reference to FIG. 1 and with reference to FIGS. The laser light L oscillated from the laser oscillator 210 passes through the beam splitters 90D and 90E, the dichroic mirror 92, and the condenser lenses 30A to 30C, and enters the plurality of near-field optical probes 100A to 100C, respectively.

The laser beam L incident on the near-field optical probes 100A to 100C passes through the optical fiber 110 and the optical waveguide 130 shown in FIG.
Near-field light is generated at 20A to 120C.

On the other hand, although overlapping with the description of the conventional etching apparatus 200, the processing surface of the work 240 is connected to the openings 120A to 120C of the near-field light probes 100A to 100C where the near-field light is generated by the stage device. When the near-field light 250 is controlled to approach, as shown in FIG. 6, the near-field light K generated near the opening 120 interacts with the surface atoms / molecules 240a of the work 240, and this near-field light K is generated by the opening 120A. A reaction gas G in the vicinity of ~ 120C is photoexcited to generate a reaction radical G ', and the reaction radical G' reacts with the atom / molecule 240a of the work 240 to generate a volatile substance B.

The volatile substance B is supplied to the exhaust tube 270
Tank 26 by a vacuum pump (not shown) connected to
It is discharged outside zero. Thus, the atoms of the work 240
The processing proceeds by the removal of the molecules 240a as volatile substances B, and the surface of the work 240 can be etched into a desired shape. At this time, as described above,
Since the etching can be performed in parallel by the plurality of near-field optical probes 100A to 100C, the processing efficiency when etching a relatively large area is improved. In addition, each of the plurality of near-field optical probes 10 is
Openings 120A to 120C of 0A to 100C and work 2
Since the etching process is performed while detecting the distance to the surface 40 online, the processing accuracy can be further improved.

The supplementary explanation of the near-field optical probes 100A to 100C of the etching apparatus 10 of the present embodiment will be given. In FIG. 4, the metal film around the light guide path 130 of each of the near-field optical probes 100A to 100C used in the present embodiment is made of aluminum or the like from which light does not seep. Thereby, the opening 120A
The exudation of light from other than ~ 120C can be prevented.

The near-field optical probes 100A to 100A
Since the vicinity of the openings 120A to 120C of C is exposed to the reaction radicals of the reaction gas generated by the near-field light and the scattered light thereof, in order to prevent corrosion and deterioration of the openings 120A to 120C, a corrosion-resistant metal is used. Metal coating with gold. Furthermore, each of the near-field optical probes 100A to 100A
C is an optical fiber type near-field optical probe.

Since the near-field light does not propagate in space, the wavelength cannot be defined. However, the scattered light that has reacted with the surface atoms and molecules of the work 240 is light that propagates in space, and the wavelength of the scattered light is near-field optical probes 100A to 100C.
Has the property of being the same as the wavelength of the laser light L incident on the laser beam L. Therefore, the wavelength of the laser beam L is appropriately selected in accordance with the type of the reaction gas, for example, a region suitable for generating reaction radicals, for example, an ultraviolet region, an infrared region, or a wavelength region having excellent thermal decomposition absorption characteristics. Thereby, a reaction radical of a desired reaction gas can be easily generated, and the etching efficiency can be improved.

Further, in the etching apparatus 10A of this embodiment, the measuring laser oscillator 87 and the photodetector 86 of the online detector 80 are arranged outside the reaction tank 260. With this configuration, the measurement laser oscillator 8 is provided outside the reaction tank 260 filled with the reaction gas.
The operation and maintenance of the photodetector 7 and the photodetector 86 become possible, and the labor for these operations is reduced.

Second Embodiment: Next, a laser beam excitation etching apparatus 1 using the near-field optical probe of the present invention.
The second embodiment will be briefly described with reference to FIG.
FIG. 2 is a perspective view showing a main configuration of the etching apparatus 10B of the present embodiment.

The etching apparatus 10 B of the present embodiment
Has substantially the same basic configuration as that shown in the first embodiment, but as shown in FIG. 2, each of a plurality (five in the drawing) of near-field optical probes 100A to 100E has: PZT stage devices 50A to 50E are attached as means for controlling the near-field optical probes 100A to 100E independently and one-dimensionally to three-dimensionally. In addition, the illustrated PZT stage devices 50A-
In 50E, it is assumed that the position control in the vertical direction (Z direction) is performed.

With this configuration, it is suitable for etching of a wide area of the work 240 and the processing efficiency can be improved. In addition, when a large number of processings of the same shape are performed in a wide area in accordance with the progress, or In addition, it is possible to cope with a case where a large number of processings of different shapes are performed in a wide area, and it is possible to provide the etching processing apparatus 10B having improved practicability.

Next, a specific sample example in which a workpiece is etched using the etching apparatuses 10A and 10B described in the above embodiments will be described. Sample 1 Workpiece: Si substrate Reactive gas: Cl ₂ Light source: Excimer laser oscillator (XeCl: wavelength λ = 30)
8 nm)

In sample 1, the reaction tank was filled with Cl ₂ as a reaction gas, and the etching was performed using the etching apparatus 10A or 10B described in each of the above embodiments.
The substrate is etched. The quantum energy of the near-field light is uniquely determined by the wavelength λ = 308 nm, and is 92 kcal / mol. On the other hand, the dissociation energy of Cl ₂ is 58 kcal / mol and the dissociation absorption edge of the molecule is 330 nm, which is sufficient to generate the reaction radical Cl.

Cl_TwoGas pressure of 20 mbar, irradiation energy
Lugie density is 440mJ / cm^TwoThe workpiece
Recon substrate etching rate is 1 pulse of laser irradiation
Approximately 0.3 mm. Energy of near-field optical probe
-Efficiency is based on an aperture diameter of 100 nm
Laser light wavelength, but it varies from infrared light to ultraviolet light.
And 10^-3-10 ^-7The shorter the wavelength, the lower the transmittance
Down. Therefore, 10 mJ / cm per pulse^Twodegree
Use a laser oscillator capable of supplying the above energy density
If three near-field optical probes are used,
3mJ / cm^TwoIf more than 10
1mJ / cm^TwoEnergy density higher than
Can withstand. Using more near-field optical probes,
If the energy density is insufficient, a higher power light source
May be used.

When etching is performed on the Si substrate with the near-field optical probe under the above conditions, a reactive radical Cl is generated only near the opening of the near-field optical probe, and is bonded to the surface atom Si of the Si substrate. The SiCl ₄ is released into the gas phase in the reaction tank. Further, SiCl ₄ is sucked by the exhaust tube and exhausted out of the reaction tank by the vacuum pump, and thus the etching process proceeds.

Sample 2 Workpiece: SiO ₂ glass Reactive gas: Cl _{2 (} gas pressure: 133 mbar) Light source: Ar ⁺ laser oscillator (wavelength λ = 457.9 n)
m): Continuous operation

In the sample 2, the reaction tank was filled with Cl ₂ as a reaction gas, and the etching was performed using the etching apparatuses 10A and 10B described in the above embodiments.
It is assumed that O ₂ glass is etched. The etching rate at this time is about 3 ° / s.

Sample 3 Workpiece: Pyrex glass (insulator) Reactive gas: Cl ₂ (gas pressure: 266 mbar) Light source: excimer laser oscillator (ArF: wavelength λ = 193)
nm)

In sample 3, the reaction vessel was filled with Cl ₂ as a reaction gas, and Py was used as a workpiece by using the etching apparatuses 10A and 10B described in the above embodiments.
It is assumed that the rex glass is etched. The etching rate at this time is about 0.15 μm / pulse at 0.5 J / cm ² , the energy density of the laser oscillator.

Sample 4 Workpiece: Al (metal) Reactive gas: Cl ₂ (gas pressure: 1.3 mbar) Light source: Excimer laser oscillator (XeCl: wavelength λ = 30)
8 nm)

In sample 4, the reaction vessel was filled with Cl ₂ as a reaction gas, and the etching was performed using the etching apparatus 10A or 10B described in each of the above embodiments.
(Metal) is etched. The etching rate at this time is the energy density of the laser oscillator,
It is about 30 ° / s at 0.3 J / cm ² .

The laser beam-excited etching processing apparatus and processing method using the near-field optical probe of the present invention are not limited to the above embodiments and samples, and various modifications can be made. For example, the light source of near-field light, the light transmission means, or the online detector is not limited to the configuration examples shown in the above embodiments. In the above embodiment, the configuration in which the measuring laser oscillator and the photodetector of the on-line detector are installed outside the reaction tank has been described.

In the above-mentioned on-line detector, a laser oscillator for measurement is separately provided, and the reflected laser light is detected by the light detector. However, the laser light is generated by the interaction between the near-field light and the surface atoms and molecules of the work. It may be configured to detect the scattered light. It goes without saying that the etching apparatus and the etching method of the present invention are not limited to the types of the reaction gas and the workpiece shown in each of the above samples.

[0096]

The laser beam excitation etching apparatus and method using the near-field optical probe of the present invention have the following excellent effects because they are configured as described above. (1) As described in claim 1, the etching apparatus according to the present invention is a photo-excited etching apparatus that optically excites a reaction gas in a reaction tank and performs an etching process on a workpiece. With the configuration using the near-field optical probe which can be controlled in each of the above, an etching apparatus suitable for etching a wide area of the workpiece and having improved processing efficiency can be obtained.

(2) In a photo-excited etching apparatus for etching a workpiece by photo-exciting a reaction gas in a reaction tank as described in claim 2, a plurality of proximity-controllable devices each of which can be independently position-controlled. A field light probe, a laser oscillator serving as a light source of the near field light generated by each near field light probe, and a laser of the laser oscillator are condensed and incident on each near field light probe through a window provided in the reaction tank. When a configuration including a condensing lens is provided, etching can be performed independently by a plurality of near-field optical probes, so that it is suitable for etching of a wide area of a workpiece and processing efficiency can be improved. Also, it is possible to cope with a case where a large number of processings of the same shape are performed in a wide area, or a case where a large number of processings of different shapes are performed in a wide area,
An etching apparatus with improved practicability can be provided.

(3) As described in claim 3, a stage device for controlling the one-dimensional to three-dimensional position of the near-field optical probe as means for enabling the position control of the near-field optical probe independently. With such a configuration, it is possible to provide an etching apparatus provided with suitable means capable of controlling the position of each near-field optical probe independently.

(4) As described in claim 4, when a fiber probe is used as the near-field light probe, a suitable etching process provided with a near-field light probe excellent in near-field light generation efficiency is provided. It can be a device.

(5) As described in claim 5, the metal coating of the optical waveguide portion of the near-field optical probe is made of a highly reflective material such as aluminum, and the vicinity of the opening is made of a corrosion-resistant metal such as gold. With the coated configuration, it is possible to prevent seepage of light from portions other than the opening and to prevent corrosion and deterioration of the opening of the near-field optical probe due to reaction with the reaction gas.

(6) As described in claim 6, when the light source for photoexcitation is configured to use a light source in a wavelength region of an ultraviolet region, when Cl ₂ or a fluorine compound is used as a reaction gas, electronic excitation is performed. And a laser light excitation etching apparatus equipped with a light source suitable for generating reaction radicals.

(7) As described in claim 7, when the light source for photoexcitation is configured to use a light source in the wavelength region of the infrared region, a light source suitable for generating reaction radicals by resonance excitation of molecules. And a laser beam excitation etching apparatus provided with:

(8) As described in claim 8, when the light source for photoexcitation is configured to use a light source in a wavelength region excellent in the thermal decomposition and absorption characteristics of the reaction gas, it absorbs ultraviolet rays such as SF _6. In the case of using a reaction gas that is not used, it is possible to provide a laser beam excited etching apparatus provided with a light source suitable for generating a reaction radical.

(9) According to a ninth aspect of the present invention, when an on-line detector for detecting the distance between the near-field optical probe and the workpiece is provided, the distance between the near-field optical probe and the workpiece can be reduced. Since the etching can be performed while detecting the distance, the processing accuracy can be further improved.

(10) As described in claim 10, the on-line detector includes a measuring laser oscillator for generating a measuring laser beam for irradiating a workpiece, and a near-field light formed by the measuring laser. However, it is configured as an online detector having a photodetector that detects a distance between the opening of the near-field optical probe and the workpiece by detecting scattered light generated by an interaction with the workpiece. Then, when the laser light from the laser oscillator that optically excites the reaction gas cannot be used for distance measurement or is difficult to use, it is possible to provide an etching apparatus equipped with an online detector effective for distance measurement.

(11) As described in the eleventh aspect, the on-line detector detects the scattered light due to the action of the near-field light and the workpiece to determine the distance between the near-field light probe and the workpiece. If it is configured as an online detector equipped with a photodetector to detect, the above distance can be detected by scattered light, and there is no need to use a separate measurement laser oscillator to generate a measurement laser to irradiate the workpiece. The structure of the online detector is simplified, and an etching apparatus with reduced manufacturing costs and maintenance costs can be provided.

(12) As described in the twelfth aspect, when the measuring laser oscillator is provided in the reaction tank,
A laser oscillator for measurement is attached near the workpiece to increase the amount of light reaching the opening of the near-field optical probe, so the accuracy of detecting the distance between the near-field optical probe and the workpiece is improved. And the processing accuracy of the etching processing is further improved.

(13) As described in claim 13, when the laser oscillator for measurement is arranged outside the reaction tank,
The operation and maintenance of the measurement laser oscillator can be performed outside the reaction tank filled with the reaction gas, and these efforts are reduced.

(14) When the photodetector is installed in the reaction tank as described in claim 14, the photodetector can be mounted near the workpiece, so that the light collection efficiency of the detection light increases. In addition, the accuracy of detecting the distance between the near-field optical probe and the workpiece is improved, and the processing accuracy of the etching process is further improved.

(15) When the photodetector is installed outside the reaction tank, the operation and maintenance of the photodetector can be performed outside the reaction tank filled with the reaction gas. , These efforts are reduced.

(16) In the etching method according to the present invention, as described in claim 16, a laser beam-excited etching apparatus using the near-field optical probe according to any one of claims 1 to 8 is used. By operating a plurality of near-field optical probes to perform desired fine processing on the surface of the workpiece, an etching method suitable for etching a wide area of the workpiece and improving the processing efficiency is provided. Can be.

(17) As described in claim 17, the laser light excitation etching apparatus using the near-field optical probe according to any one of claims 9 to 15 is used to form an opening of the near-field optical probe and cover the same. By operating a plurality of near-field optical probes and performing desired micro-processing on the surface of the workpiece while online detecting the distance to the workpiece, it is suitable for etching of a wide area of the workpiece. Efficiency can be improved, and processing can be performed while online detecting the distance between the opening of the near-field optical probe and the workpiece, so that processing accuracy can be further improved.

[Brief description of the drawings]

FIG. 1 is a side view showing a basic configuration of a first embodiment of a laser beam excitation etching apparatus using a near-field optical probe of the present invention.

FIG. 2 is a perspective view showing a main configuration of a second embodiment of a laser beam excited etching apparatus using a near-field optical probe according to the present invention.

FIG. 3 is a conceptual diagram illustrating the principle of generation of near-field light and characteristics of near-field light.

FIG. 4 is a vertical sectional side view showing a structure of a near-field optical probe.

FIG. 5 is a side view showing a basic configuration of a conventional laser beam excited etching apparatus using a near-field optical probe.

FIG. 6 is a partially cutaway perspective view for explaining an etching process using near-field light generated in an opening of the near-field light probe.

[Explanation of symbols]

 10, 10A, 10B: Etching processing apparatus 30A to 30C: Condensing lens 50A to 50E: PZT stage apparatus 80: Online detector 86A to 86C: Photodetector 87: Laser oscillator for measurement 100A to 100C: Near-field optical probe 210 : Laser oscillator 240: work (workpiece) 260: reaction tank 262: process window (window) L: laser beam L ': laser beam for measurement

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F065 AA06 BB01 CC19 DD06 FF00 GG04 GG05 HH13 JJ01 JJ09 LL04 LL20 LL46 NN20 PP12 4K057 DA11 DB05 DB06 DB20 DD06 DE01 DE06 DM40 DN01 DN03 DN10 5F004 AA16 DA04 DB03 DB01

Claims (17)

[Claims] 1. A photo-excited etching apparatus for photo-exciting a reaction gas in a reaction tank to perform etching on a workpiece, wherein a plurality of controllable near-field optical probes are used as the photo-excitation means. Laser beam excitation etching apparatus using near-field optical probe. 2. A photo-excited etching apparatus for photo-exciting a reaction gas in a reaction tank to perform etching on an object to be processed, comprising: a plurality of near-field light probes each capable of independently controlling the position; A laser oscillator serving as a light source of a near-field light generated by a probe, and a condensing lens for condensing a laser of the laser oscillator and entering each of the near-field light probes through a window provided in the reaction tank. A laser light-excited etching apparatus using a near-field optical probe, comprising: 3. A stage device for controlling one-dimensional to three-dimensional positions of the near-field optical probe as means for independently controlling the position of the near-field optical probe. Item 3. A laser beam excitation etching apparatus using the near-field optical probe according to Item 2. 4. The laser beam excitation etching apparatus using a near-field optical probe according to claim 1, wherein a fiber probe is used as the near-field optical probe. 5. A metal film of an optical waveguide portion of the near-field optical probe is formed of a high-reflection material such as aluminum, and the vicinity of the opening is coated with a corrosion-resistant metal such as gold. A laser beam excitation etching apparatus using the near-field optical probe according to any one of 1 to 4. 6. The laser light excitation etching using a near-field light probe according to claim 1, wherein a light source in a wavelength region of an ultraviolet region is used as the light source for light excitation. Processing equipment. 7. The laser light excitation etching using a near-field light probe according to claim 1, wherein a light source in a wavelength region of an infrared region is used as the light excitation light source. Processing equipment. 8. The near-field light according to claim 1, wherein the light source for light excitation is a light source in a wavelength region excellent in thermal decomposition absorption characteristics of a reaction gas. Laser beam excitation etching equipment using a probe. 9. The near-field according to claim 1, further comprising an on-line detector for detecting a distance between an opening of each of the near-field optical probes and the workpiece. Laser light excitation etching equipment using optical probe. 10. An on-line detector, comprising: a measuring laser oscillator for generating a measuring laser beam for irradiating a workpiece; 10. An on-line detector comprising a light detector for detecting a distance between an opening of a near-field light probe and a workpiece by detecting scattered light generated by the action. Laser-excited etching equipment using near-field optical probes. 11. The on-line detector includes a photodetector that detects a distance between an opening of a near-field optical probe and a workpiece by detecting scattered light caused by the action of the near-field light and the workpiece. The laser beam excitation etching apparatus using the near-field optical probe according to claim 9, wherein the apparatus is an on-line detector provided. 12. The laser beam excitation etching apparatus using a near-field optical probe according to claim 10, wherein said measurement laser oscillator is provided in a reaction tank. 13. The laser beam-excited etching apparatus using a near-field optical probe according to claim 10, wherein the measurement laser oscillator is provided outside the reaction tank. 14. The laser beam excitation etching apparatus using a near-field optical probe according to claim 10, wherein the photodetector is provided in a reaction tank. 15. The laser beam excitation etching apparatus using a near-field optical probe according to claim 10, wherein the photodetector is provided outside the reaction tank. 16. A plurality of near-field optical probes are operated using the laser-light-excited etching processing apparatus using the near-field optical probe according to claim 1, so that a desired surface is formed on the surface of the workpiece. A laser beam-excited etching method using a near-field optical probe, characterized in that micromachining is performed. 17. A method for laser-excited etching using the near-field optical probe according to claim 9, wherein the distance between the opening of the near-field optical probe and the workpiece is detected online. A laser light-excited etching method using a near-field optical probe, wherein a plurality of near-field optical probes are operated to perform desired fine processing on the surface of the workpiece.