JP2009006378A - Microfabrication method and microfabrication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform highly accurate correction with a comparatively easy manipulation, to perform a continuously long time operation, and also to prevent machining accuracy from lowering by heat drift. <P>SOLUTION: A microfabrication apparatus includes: a cantilever 11 in which a probe 1 is formed in the free end of an atomic force microscope; an XYZ scanner 12 which is a driving means for driving the cantilever 11 as well as the probe 1; and a femtosecond laser irradiation means composed of a femtosecond laser light source 4 for emitting a femtosecond laser 3 to the probe 1 and of an objective lens 5. The probe 1 is opposed to a sample 6 with a pattern formed on one primary face, is brought into contact with an extra portion of the pattern formed on the sample 6 and is driven. As a result, the extra portion is removed, with the femtosecond laser 3 emitted from the femtosecond laser irradiation means to machining waste 2 which is stuck to the probe 1 after the removal of the extra portion, and with the machining waste 2 removed by laser ablation. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a micromachining method and a micromachining apparatus for removing excess portions of a micropattern such as a semiconductor integrated circuit.

  In response to the demand for miniaturization of semiconductor integrated circuits, lithography has responded with super-resolution technology and modified illumination technology, such as shortening the wavelength of the light source of the reduction projection exposure apparatus, increasing the NA, and a phase shift mask. Further, defect correction of a photomask, which is required to be defect-free in a transfer original of a reduction projection exposure apparatus, has been conventionally performed using a laser or a focused ion beam.

  However, the resolution was insufficient with a laser, and the defects of the most advanced fine patterns could not be corrected. On the other hand, in a focused ion beam (hereinafter referred to as FIB), imaging damage (decrease in transmittance) of a glass portion due to implantation of gallium used as a primary beam due to a shortened wavelength of a light source of a reduction projection exposure apparatus. Has become a problem. For this reason, there is a need for a defect correction technique that can correct defects in fine patterns and that does not cause imaging damage. In FIB, gas-assisted etching is introduced to improve the transmittance of the glass part. However, in the case of a chromium mask that does not have a supporting gas that can be processed at a high etch rate, the transmittance is improved by gas-assisted etching. However, the black defect correction portion (hereinafter referred to as the surplus portion) cannot be completely removed, and there is a problem that the transmittance is lowered.

  In response to the above-mentioned demands, an atomic force microscope with high resolution and high position control has recently been used in the low-load contact mode and intermittent contact mode with no imaging damage to the surplus portion of the photomask. Atomic force microscope scratching, in which the surplus portion is physically removed with a probe made of a material harder than the surplus portion that is a material to be processed using (AFM), has come to be applied (Non-Patent Literature). 1).

  Of course, this method does not cause gallium to be injected into the glass portion unlike FIB, so that there is no inconvenience that the transmittance is poor even if the shape after correction is good. In addition, the photomask can be corrected by a relatively easy operation. However, in this processing method, there is a problem in that processing scraps made of surplus material are deposited around the processing portion and at the same time processing scraps adhere to the tip of the probe during processing.

  As described above, when the processing dust adheres to the tip of the probe, when there are two projections on the tip of the probe, both projections detect an atomic force and form a superimposed (convolved) image. Since it becomes a chip image and high-precision positioning of the processing region cannot be performed, it is necessary to remove the processing waste adhering to the tip of the probe.

  In addition, if machining debris accumulates and adheres to the tip of the probe, the probe may not function as a machining needle, and the excess portion may not be cut away. In this case, too, the tip adheres to the tip of the probe to restore machining capability. There was a need to remove the scrap removal.

  Therefore, in order to remove the processing dust adhering to the tip of the probe, the probe is scanned against a soft material that is a cleaning pattern, or a steep pattern that is a cleaning pattern is scanned with a high load. It was.

  However, these cleaning patterns are placed outside the mask and the stage needs to be moved every time it is cleaned, making it difficult to work continuously for a long time. It was also. Thermal drift is the time displacement of material expansion and contraction due to heat, and even if the same position is intended to be observed due to this time displacement, the field of view is shifted. For example, if the stage on which the photomask is placed is moved for a long distance using a screw called a ball screw, heat is generated due to friction and a thermal drift occurs that causes the ball screw to expand (turns to contraction over time). Even if the stage is stopped when the desired position is reached, the field of view of the photomask on the stage shifts from moment to moment due to this thermal drift, and shifts from the position to be processed, so that the processing accuracy decreases.

In addition, by using a femtosecond laser with a short pulse, the thermal effect during processing is reduced, and laser ablation processing of a chromium film and a MOSiON phase shift film with little damage to the underlying glass substrate can be performed. (Refer nonpatent literature 2). The above thermal effect means that if the pulse width is long, the absorbed laser energy will be converted into lattice vibration energy as well as breaking the chemical bond and the temperature will rise, and this heat should not absorb the laser. It shows that the surrounding materials are also denatured. When the chrome mask is used as a photomask, the underlying glass of the chrome film irradiated with the laser may be damaged by heat, and the optical characteristics at the correction location may be deteriorated due to the sag. On the other hand, when a femtosecond laser is used, since the pulse width is short and it is hardly converted into lattice vibration, the material that should not absorb the surrounding laser is not modified.
Y. Morikawa, H .; Kokubo, M .; Nishiguchi, N .; Hayashi, R .; White, R.A. Bozak, and L.L. Terrill, Proc. of SPIE 5130 520-527 (2003) R. White, J. et al. LeClaire, T .; Robinson, A.M. Dinsdale, R.D. Bozak, and D.D. A. Lee, Proc. of SPIE 6349 6349F-1-6349F-11 (2006)

  The object of the present invention is to enable fine correction of a fine pattern such as a photomask with a relatively easy operation, enable continuous work for a long time, and prevent a reduction in processing accuracy due to thermal drift. It is to provide a method and a microfabrication apparatus.

  According to a first aspect of the present invention, a probe formed at a free end of a cantilever of an atomic force microscope is brought into contact with a surplus portion of a pattern formed on a sample arranged opposite to the probe. In the micromachining method that removes the surplus part by driving, a femtosecond laser is irradiated to the machining waste adhering to the probe after removal of the surplus part, and the machining waste is removed by laser ablation. It is characterized by.

  In the first invention according to the present invention, since a pattern is processed using a probe of an atomic force microscope, it becomes possible to correct a fine pattern such as a photomask with high accuracy by a relatively easy operation. .

  As described above, when a femtosecond laser is used, the pulse width is short and it is hardly converted to lattice vibration. Therefore, only the machining waste is efficiently removed without denature the probe to which the excess portion of the machining waste is attached. It is possible. In addition, since the machining waste can be removed without removing the probe from the pattern, it is possible to continuously work for a long time and to prevent a reduction in machining accuracy due to thermal drift.

  According to a second aspect of the present invention, when a femtosecond laser is applied to the processing waste, a protective plate is disposed between the probe and the sample, and the processing waste removed by the laser ablation is applied to the sample. It is characterized by preventing adhesion.

  If the processing waste adhering to the probe is removed as described above, the processing waste may fall on the sample. However, if the protective plate is provided as described above, the sample is covered with the protective plate, and the processing dust is prevented from adhering to the sample.

  According to a third aspect of the present invention, there is provided a micromachining apparatus comprising a cantilever having a probe formed at a free end of an atomic force microscope and a driving means for driving the probe by driving the cantilever. And a femtosecond laser irradiation means for irradiating a femtosecond laser, the probe is opposed to a sample having a pattern formed on one main surface, and is in contact with an excess portion of the pattern formed on the sample. By driving it, the surplus portion is removed, and the processing waste adhering to the probe after removal of the surplus portion is irradiated with femtosecond laser from the femtosecond laser irradiation means, and the processing waste is removed by laser ablation. It is characterized by doing.

According to a fourth aspect of the present invention, in the microfabrication apparatus as described above, the femtosecond laser irradiation unit irradiates a femtosecond laser from a direction substantially orthogonal to a direction opposite to the sample of the probe. After removing the excess part, the side surface of the probe in a direction substantially perpendicular to the direction opposite to the sample is irradiated with femtosecond laser to remove the processing dust adhering to the probe. It is characterized by doing.
In the microfabrication apparatus having such a configuration, it is possible to efficiently remove the machining waste on the side surface of the probe where the machining waste is relatively easily attached.

According to a fifth aspect of the present invention, in the microfabrication apparatus as described above, a protective plate is disposed on the contact end side to the probe pattern.
According to a sixth aspect of the present invention, in the microfabrication apparatus as described above, the probe has a rotation mechanism that rotates the probe about a direction opposite to the sample of the probe as a rotation axis, and removes an excess portion. A femtosecond laser is irradiated while rotating the probe later, and the processing waste adhering to the probe is removed.
In the micromachining apparatus having such a configuration, since the femtosecond laser is irradiated while rotating the probe, the machining debris on the entire side surface of the probe to which the machining debris is relatively attached is efficiently removed. It becomes possible.

In the present invention, since a pattern is processed using a probe of an atomic force microscope, a fine pattern such as a photomask can be corrected with high accuracy by a relatively easy operation.
As described above, when the femtosecond laser is used, it is possible to efficiently remove only the machining waste without modifying the probe to which the excess portion of the machining waste is attached. In addition, since the processing debris can be removed without removing the probe from the pattern, it is possible to work continuously for a long time, prevent deterioration of processing accuracy due to thermal drift, and improve throughput. In addition, high-precision processing is possible.

Further, in the present invention, when irradiating the femtosecond laser to the processing waste, a protective plate is arranged between the probe and the sample, so that the sample is covered with the protective plate, and the processing waste adheres to the sample. It is prevented and processing with higher accuracy becomes possible.
Furthermore, in the present invention, since the femtosecond laser is irradiated while rotating the probe, it becomes possible to efficiently remove the machining waste on the entire side surface of the probe, on which the machining waste is relatively easily attached. Throughput improvement and high-precision machining are possible.

  Hereinafter, a first embodiment of a microfabrication apparatus according to the present invention will be described in detail with reference to FIG.

  As shown in FIG. 1, the microfabrication apparatus according to the present embodiment includes a cantilever 11 in which a probe 1 is formed at a free end of an atomic force microscope, and driving means that drives the probe 1 by driving the cantilever 11. , An XYZ scanner 12, a femtosecond laser light source 4 for irradiating the probe 1 with a femtosecond laser 3, and an objective lens 5. The probe 1 is placed on one main surface. The probe 6 is made to face the sample 6 having a pattern formed thereon, and is driven in contact with the surplus portion of the pattern formed on the sample 6 to remove the surplus portion, and the probe 1 after the surplus portion is removed. The femtosecond laser 3 is irradiated from the femtosecond laser irradiation means to the processing waste 2 adhering to the surface, and the processing waste 2 is removed by laser ablation.

  In the microfabrication apparatus of the present embodiment, the femtosecond laser irradiation means is provided so as to irradiate the femtosecond laser 3 from a direction substantially orthogonal to the direction of the probe 1 facing the sample 6. The processing chip 2 attached to the probe 1 is irradiated with the femtosecond laser 3 on the side surface in the direction substantially orthogonal to the direction opposite to the sample 6 of the probe 1 after the excess portion is removed. It is designed to be removed.

  In the atomic force microscope, the sharp tip 1 attached to the tip of a cantilever (cantilever cantilever) 11 is brought close to the surface of the sample 6, and the atomic force acting between the probe 1 and the surface of the sample 6 is applied to the cantilever 11. An apparatus that obtains the surface shape of a fine region by raster scanning in the XY direction while controlling the height of the cantilever 11 with an XYZ scanner (piezo element or voice coil motor) 12 so that the atomic force is detected by displacement. It is. The displacement of the cantilever 11 is controlled by irradiating the laser beam 13 from the laser light source 14 to the back surface of the cantilever 11 and detecting the reflected laser beam 13 by the four-divided photodetector 15, or at the root of the cantilever 11. This is done by detecting the strain caused by the displacement of the cantilever 11 as a change in resistance using an effective material and controlling the result as a change in resistance.

  At this time, in the microfabrication apparatus of the present embodiment, as described above, the surplus portion of the pattern (not shown) formed on the sample 6 is removed by the probe 1, but the atomic force microscope is used. From the determination of the surplus part (so-called black defect) that is the processing region using the high-resolution surface shape observation and positioning capability of the atomic force microscope, and applying a high load using the high positioning capability only in the determined processing region or The black defect is corrected by performing mechanical removal processing locally with the Z feedback turned off and the height in the Z direction kept constant.

  The difference between the normal atomic force microscope and the atomic force microscope used in the microfabrication apparatus of the present embodiment is that the high load acting on the machining resistance or the Z feedback is turned off and the height in the Z direction is made constant. In order to prevent the machining position from shifting when the mechanical removal process is locally performed, a cantilever 11 having a high spring constant is used so that the cantilever 11 is not twisted and cannot be cut. And the use of a probe 1 (working probe) made of a material harder than the work material constituting the black defect so that the black defect can be reliably cut.

  Even if a harder cantilever and a harder probe than usual are used to achieve high-precision machining, the micromachining device simultaneously processes during observation to recognize the machining area. If an area that does not need to be damaged is damaged, a defect is created. Therefore, it is necessary to avoid damaging at the time of observation. In order to make this possible, the detection sensitivity of the atomic force is higher than that in the contact mode (it is possible to observe even less interaction between the probe and the sample (sample), so there is less damage) to recognize the processing area in the dynamic mode Is being observed. In the dynamic mode (amplitude modulation type dynamic mode), the distance information between the probe 1 and the sample 6 is controlled so that the vibration amplitude of the cantilever 11 is constant in a state where the cantilever 11 is resonated, and the height information corresponding to the XY scanning point. Observation is performed by imaging.

  In the microfabrication apparatus according to the present embodiment, when the black chip is repaired, for example, when the processing dust 2 adheres to the probe 1 made of diamond and a double chip image is generated or cannot be cut, the processing is interrupted. As described above, the processing waste 2 attached to the probe 1 is irradiated with the femtosecond laser 3 from the femtosecond laser irradiation means, and the processing waste 2 is removed by laser ablation.

  Specifically, as shown in FIG. 1a, the femtosecond laser 3 (for example, a wavelength of 248 nm, a period of 150 fs, and an output of 3 to 7 mJ) is obtained from the femtosecond laser light source 4 while the probe 1 is pulled up from the sample 6. As shown in FIG. 1B, the processing waste 2 that is condensed and irradiated by the lens 5 and attached to the side surface of the probe 1 in the direction substantially orthogonal to the direction opposite to the sample 6 is indicated by a broken line in FIG. Remove by laser ablation.

The wavelength of the femtosecond laser used at this time is such that the processing waste such as chromium (chromium oxide) and MoSiON absorbs light, but the material constituting the probe 1 (for example, diamond or BN) does not absorb light. . However, the output of the femtosecond laser does not exceed several tens of mJ so that, for example, diamond constituting the probe 1 is not cut. The femtosecond laser irradiation position is confirmed and adjusted by irradiating a UV lamp of the same wavelength with the same objective lens with the same optical axis and imaging the transmitted light or reflected light with a CCD camera sensitive to UV light.
In the microfabrication apparatus of the present embodiment, since the pattern is processed using the probe of the atomic force microscope, the micropattern such as a photomask can be corrected with high accuracy by a relatively easy operation.

  As described above, when the femtosecond laser is used, since the pulse width is short and it is hardly converted into lattice vibration, only the machining waste 2 is efficiently used without modifying the probe 1 to which the machining waste 2 of the surplus portion is attached. Can be removed. Further, since the machining waste 2 can be removed without removing the probe 1 from the pattern, it is possible to continuously work for a long time, and to prevent a reduction in machining accuracy due to thermal drift.

Further, in the microfabrication apparatus of the present embodiment, the femtosecond laser 3 is irradiated on the side surface of the probe 1 in the direction substantially orthogonal to the direction opposite to the sample 6 and adhered to the probe 1. Since the scrap 2 is removed, the scrap 2 on the side surface of the probe 1 to which the scrap 2 is relatively easily attached can be efficiently removed.
Therefore, in the microfabrication apparatus of the present embodiment, since the pattern is processed using the probe of the atomic force microscope, it is possible to correct the micropattern such as a photomask with high accuracy by a relatively easy operation. Become.

  In addition, since the femtosecond laser is used in the microfabrication apparatus of the present embodiment, only the machining waste 2 is efficiently removed without modifying the probe 1 to which the excess portion of the machining waste 2 is attached. It is possible to remove. In addition, since the machining waste 2 can be removed without removing the probe 1 from the pattern, it is possible to work continuously for a long time, and it is possible to prevent a decrease in machining accuracy due to thermal drift, thereby improving throughput. In addition, high-precision processing is possible.

  Hereinafter, a second embodiment of the microfabrication apparatus according to the present invention will be described in detail with reference to FIG.

  Similar to the first embodiment, the microfabrication apparatus of the present embodiment is a cantilever in which the probe 1 is formed at the free end of the atomic force microscope, and the probe 1 is driven by driving the cantilever (not shown). A driving unit; and a femtosecond laser irradiation unit configured by a femtosecond laser light source 4 for irradiating the probe 1 with a femtosecond laser 3 and an objective lens 5. The probe 1 has a pattern on one main surface. The sample 6 formed is opposed to the sample 6 and is driven to contact the surplus portion of the pattern formed on the sample 6 to remove the surplus portion and adhere to the probe 1 after the surplus portion is removed. The processed scrap 2 is irradiated with femtosecond laser 3 from the femtosecond laser irradiation means, and the processed scrap 2 is removed by laser ablation.

  In the microfabrication apparatus of the present embodiment, the femtosecond laser irradiation means is provided so as to irradiate the femtosecond laser 3 from a direction substantially orthogonal to the direction of the probe 1 facing the sample 6. The processing chip 2 attached to the probe 1 is irradiated with the femtosecond laser 3 on the side surface in the direction substantially orthogonal to the direction opposite to the sample 6 of the probe 1 after the excess portion is removed. It is designed to be removed.

  In the present embodiment, parts having the same configuration as in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  Also in the present embodiment, the atomic force microscope uses a sharp tip 1 attached to the tip of a cantilever (cantilever cantilever) close to the surface of the sample 6 and an interatomic force acting between the probe 1 and the sample 6 surface. The surface of a fine region is detected by raster scanning in the XY direction while controlling the height of the cantilever with an XYZ scanner (piezo element or voice coil motor) (not shown) so that the force is detected by the displacement of the cantilever and the atomic force is constant. It is a device that obtains the shape. The displacement of the cantilever is controlled in the same manner as in the first embodiment.

  Also in the microfabrication apparatus of the present embodiment, as in the microfabrication apparatus of the first embodiment, the probe 1 removes an excess portion of a pattern (not shown) formed on the sample 6, but uses an atomic force microscope. Therefore, using the high-resolution surface shape observation and positioning capability of the atomic force microscope, it is possible to determine the surplus part (so-called black defect) that is the processing region and high load using high positioning capability only in the determined processing region The black defect is corrected by applying mechanical removal processing while applying Z or turning off the Z feedback and keeping the height in the Z direction constant.

  The difference between the normal atomic force microscope and the atomic force microscope diverted to the microfabrication apparatus of the present embodiment is the same as in the first embodiment. When performing mechanical removal processing locally at a constant height, the spring constant as a cantilever is used so that the cantilever is not twisted against cutting resistance and cannot be cut so that the processing position does not shift. In other words, a probe 1 (working probe) made of a material harder than the work material constituting the black defect is used so that the black defect can be reliably cut.

  In the atomic force microscope used in the present embodiment using a harder cantilever and a hard probe than usual, it is necessary to perform processing during observation for recognizing a processing region in the same manner as in the fine processing apparatus of the first embodiment. In order to avoid damaging the region where there is no damage, the observation is performed by controlling the distance between the probe 1 and the sample 6 so that the vibration amplitude of the cantilever is constant while the cantilever is resonated, Observation is performed in a so-called dynamic mode with little damage.

  And also in the microfabrication apparatus of the present embodiment, as in the microfabrication apparatus of the first embodiment, during the black defect correction, the processing dust 2 adheres to the probe 1 made of diamond, for example, and a double chip image is generated. When it becomes impossible to cut, the processing is interrupted, and the processing waste 2 attached to the probe 1 is irradiated with the femtosecond laser 3 from the femtosecond laser irradiation means as described above, and the processing waste 2 is removed by laser ablation. To do.

  Specifically, as shown in FIG. 2a, the femtosecond laser 3 (for example, wavelength 248 nm, period 150 fs, output 3 to 7 mJ) from the femtosecond laser light source 4 with the probe 1 pulled up from the sample 6 is an objective. As shown in FIG. 2 (b), the processing waste 2 that is condensed and irradiated by the lens 5 and adhered to the side surface of the probe 1 in the direction substantially orthogonal to the direction opposite to the sample 6 is indicated by a broken line in FIG. Remove by laser ablation.

The wavelength of the femtosecond laser used at this time is such that the processing waste such as chromium (chromium oxide) and MoSiON absorbs light, but the material constituting the probe 1 (for example, diamond or BN) does not absorb light. . However, the output of the femtosecond laser does not exceed several tens of mJ so that, for example, diamond constituting the probe 1 is not cut. The femtosecond laser irradiation position is confirmed and adjusted by irradiating a UV lamp of the same wavelength with the same objective lens with the same optical axis and imaging the transmitted light or reflected light with a CCD camera sensitive to UV light.
In the microfabrication apparatus according to this embodiment, as shown in FIG. 2, a protective plate 7 is disposed on the contact end side of the probe 1 with respect to the pattern.

  Specifically, as shown in FIG. 2a, the femtosecond laser 3 (for example, wavelength 248 nm, period 150 fs, output 3 to 7 mJ) from the femtosecond laser light source 4 with the probe 1 pulled up from the sample 6 is an objective. When the processing dust 2 attached to the side surface in the direction substantially orthogonal to the direction opposite to the sample 6 of the probe 1 is removed by laser ablation as described above, the probe is irradiated. A protective plate 7 is disposed between 1 and the sample 6.

  When the processing waste 2 attached to the probe 1 is removed as described above, the processing waste 2 may fall on the sample 6. However, if the protective plate 7 is provided as in the present embodiment, the sample 6 is covered with the protective plate 7, so that the processing dust 2 is prevented from adhering to the sample and processing with higher accuracy is possible.

Further, in the microfabrication apparatus of the present embodiment, as shown in FIG. 2B, after the machining waste 2 attached to the probe 1 is removed as shown by the broken line, the protection to which the dropped machining waste 8 is attached. It is sufficient to remove the plate 7 from the sample 6 and continue the processing operation, and the throughput can be further improved.
Needless to say, the microfabrication apparatus of the present embodiment also has the same effect as the microfabrication apparatus of the first embodiment.

  That is, in the microfabrication apparatus of the present embodiment, similarly to the microfabrication apparatus of the first embodiment, since the pattern is processed using the probe of the atomic force microscope, a photomask or the like can be performed with relatively easy operation. The fine pattern can be corrected with high accuracy.

  As described above, when the femtosecond laser is used, since the pulse width is short and it is hardly converted into lattice vibration, only the machining waste 2 is efficiently used without modifying the probe 1 to which the machining waste 2 of the surplus portion is attached. Can be removed. Further, since the machining waste 2 can be removed without removing the probe 1 from the pattern, it is possible to continuously work for a long time, and to prevent a reduction in machining accuracy due to thermal drift.

  In the micromachining apparatus of the present embodiment, similarly to the micromachining apparatus of the first embodiment, the femtosecond laser 3 is irradiated on the side surface of the probe 1 in a direction substantially orthogonal to the direction facing the sample 6. Thus, the processing waste 2 adhering to the probe 1 is removed, so that the processing waste 2 on the side surface of the probe 1 to which the processing waste 2 is relatively easily attached can be efficiently removed. It becomes possible.

  Therefore, in the microfabrication apparatus of the present embodiment, as with the microfabrication apparatus of the first embodiment, since the pattern is processed using the probe of the atomic force microscope, a photomask or the like can be performed with relatively easy operations. The fine pattern can be corrected with high accuracy.

  Further, in the micromachining apparatus of the present embodiment, similarly to the micromachining apparatus of the first embodiment, since the femtosecond laser is used, the probe 1 to which the excess portion of the processing waste 2 is attached is denatured. Therefore, it is possible to efficiently remove only the processing waste 2. In addition, since the machining waste 2 can be removed without removing the probe 1 from the pattern, it is possible to work continuously for a long time, and it is possible to prevent a decrease in machining accuracy due to thermal drift, thereby improving throughput. In addition, high-precision processing is possible.

  Hereinafter, a third embodiment of the microfabrication apparatus according to the present invention will be described in detail with reference to FIG.

  Similar to the first embodiment, the microfabrication apparatus of the present embodiment is a cantilever in which the probe 1 is formed at the free end of the atomic force microscope, and the probe 1 is driven by driving the cantilever (not shown). A driving unit; and a femtosecond laser irradiation unit configured by a femtosecond laser light source 4 for irradiating the probe 1 with a femtosecond laser 3 and an objective lens 5. The probe 1 has a pattern on one main surface. The sample 6 formed is opposed to the sample 6 and is driven to contact the surplus portion of the pattern formed on the sample 6 to remove the surplus portion and adhere to the probe 1 after the surplus portion is removed. The processed scrap 2 is irradiated with femtosecond laser 3 from the femtosecond laser irradiation means, and the processed scrap 2 is removed by laser ablation.

  In the microfabrication apparatus of the present embodiment, the femtosecond laser irradiation means is provided so as to irradiate the femtosecond laser 3 from a direction substantially orthogonal to the direction of the probe 1 facing the sample 6. The processing chip 2 attached to the probe 1 is irradiated with the femtosecond laser 3 on the side surface in the direction substantially orthogonal to the direction opposite to the sample 6 of the probe 1 after the excess portion is removed. It is designed to be removed.

  In the present embodiment, parts having the same configuration as in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  Also in the present embodiment, the atomic force microscope uses a sharp tip 1 attached to the tip of a cantilever (cantilever cantilever) close to the surface of the sample 6 and an interatomic force acting between the probe 1 and the sample 6 surface. The surface of a fine region is detected by raster scanning in the XY direction while controlling the height of the cantilever with an XYZ scanner (piezo element or voice coil motor) (not shown) so that the force is detected by the displacement of the cantilever and the atomic force is constant. It is a device that obtains the shape. The displacement of the cantilever is controlled in the same manner as in the first embodiment.

  Also in the microfabrication apparatus of the present embodiment, as in the microfabrication apparatus of the first embodiment, the probe 1 removes an excess portion of a pattern (not shown) formed on the sample 6, but uses an atomic force microscope. Therefore, using the high-resolution surface shape observation and positioning capability of the atomic force microscope, it is possible to determine the surplus part (so-called black defect) that is the processing region and high load using high positioning capability only in the determined processing region The black defect is corrected by applying mechanical removal processing while applying Z or turning off the Z feedback and keeping the height in the Z direction constant.

  The difference between the normal atomic force microscope and the atomic force microscope diverted to the microfabrication apparatus of the present embodiment is the same as in the first embodiment. When performing mechanical removal processing locally at a constant height, the spring constant as a cantilever is used so that the cantilever is not twisted against cutting resistance and cannot be cut so that the processing position does not shift. In other words, a probe 1 (working probe) made of a material harder than the work material constituting the black defect is used so that the black defect can be reliably cut.

  In the atomic force microscope used in the present embodiment using a harder cantilever and a hard probe than usual, it is necessary to perform processing during observation for recognizing a processing region in the same manner as in the fine processing apparatus of the first embodiment. In order to avoid damaging the region where there is no damage, the observation is performed by controlling the distance between the probe 1 and the sample 6 so that the vibration amplitude of the cantilever is constant while the cantilever is resonated, Observation is performed in a so-called dynamic mode with little damage.

  And also in the microfabrication apparatus of the present embodiment, as in the microfabrication apparatus of the first embodiment, during the black defect correction, the processing dust 2 adheres to the probe 1 made of diamond, for example, and a double chip image is generated. When it becomes impossible to cut, the processing is interrupted, and the processing waste 2 attached to the probe 1 is irradiated with the femtosecond laser 3 from the femtosecond laser irradiation means as described above, and the processing waste 2 is removed by laser ablation. To do.

  Specifically, as shown in FIG. 2a, the femtosecond laser 3 (for example, wavelength 248 nm, period 150 fs, output 3 to 7 mJ) from the femtosecond laser light source 4 with the probe 1 pulled up from the sample 6 is an objective. The processing waste 2 that is collected by the lens 5 and irradiated, reflected by the galvanometer mirror 10, etc. and adhered to the side surface of the probe 1 in a direction substantially orthogonal to the direction opposite to the sample 6 as described above is shown in FIG. Removed by laser ablation as shown by the broken line in b).

  The wavelength of the femtosecond laser used at this time is such that the processing waste such as chromium (chromium oxide) and MoSiON absorbs light, but the material constituting the probe 1 (for example, diamond or BN) does not absorb light. . However, the output of the femtosecond laser does not exceed several tens of mJ so that, for example, diamond constituting the probe 1 is not cut. The femtosecond laser irradiation position is confirmed and adjusted by irradiating a UV lamp of the same wavelength with the same objective lens with the same optical axis and imaging the transmitted light or reflected light with a CCD camera sensitive to UV light.

  In particular, the microfabrication apparatus of the present embodiment has a rotating mechanism that rotates the probe 1 around a direction opposite to the sample 6 of the probe 1 as a rotation axis, and the probe 1 after the excess portion is removed. The femtosecond laser 3 is irradiated while rotating the workpiece 2 so as to remove the processing waste 2 adhering to the probe 1.

  Specifically, as shown in FIG. 3, a probe that rotates the probe 1 by rotating the cantilever to the opposite side of the tip of the cantilever having the probe 1 at the tip. A rotating mechanism 9 is provided, and after removing the processing waste 2 adhering to one side of the probe 1 as shown in FIG. 3 (a), the cantilever is rotated as shown in FIG. 3 (b). The probe 1 is rotated to remove the processing waste 2 on the side surface opposite to the probe 1.

Then, the rotation of the probe 1 and the removal of the machining waste 2 by the laser ablation of the femtosecond laser 3 are repeated until the machining waste 2 attached to the tip of the probe 1 can be completely removed.
In the fine processing apparatus of this embodiment, since the femtosecond laser is irradiated while rotating the probe 1, the processing waste 2 on the entire side surface of the probe 1 to which the processing waste 2 is relatively attached is efficiently removed. As a result, further throughput improvement and high-precision processing are possible.
Needless to say, the microfabrication apparatus of the present embodiment also has the same effect as the microfabrication apparatus of the first embodiment.

That is, in the microfabrication apparatus of the present embodiment, similarly to the microfabrication apparatus of the first embodiment, since the pattern is processed using the probe of the atomic force microscope, a photomask or the like can be performed with relatively easy operation. The fine pattern can be corrected with high accuracy.
As described above, when the femtosecond laser is used, since the pulse width is short and it is hardly converted into lattice vibration, only the machining waste 2 is efficiently used without modifying the probe 1 to which the machining waste 2 of the surplus portion is attached. Can be removed. Further, since the machining waste 2 can be removed without removing the probe 1 from the pattern, it is possible to continuously work for a long time, and to prevent a reduction in machining accuracy due to thermal drift.

  In the micromachining apparatus of the present embodiment, similarly to the micromachining apparatus of the first embodiment, the femtosecond laser 3 is irradiated on the side surface of the probe 1 in a direction substantially orthogonal to the direction facing the sample 6. Thus, the processing waste 2 adhering to the probe 1 is removed, so that the processing waste 2 on the side surface of the probe 1 to which the processing waste 2 is relatively easily attached can be efficiently removed. It becomes possible.

  Therefore, in the microfabrication apparatus of the present embodiment, as with the microfabrication apparatus of the first embodiment, since the pattern is processed using the probe of the atomic force microscope, a photomask or the like can be performed with relatively easy operations. The fine pattern can be corrected with high accuracy.

  Further, in the micromachining apparatus of the present embodiment, similarly to the micromachining apparatus of the first embodiment, since the femtosecond laser is used, the probe 1 to which the excess portion of the processing waste 2 is attached is denatured. Therefore, it is possible to efficiently remove only the processing waste 2. In addition, since the machining waste 2 can be removed without removing the probe 1 from the pattern, it is possible to work continuously for a long time, and it is possible to prevent a decrease in machining accuracy due to thermal drift, thereby improving throughput. In addition, high-precision processing is possible.

It is the schematic which shows the 1st Example of the microfabrication apparatus to which this invention is applied. It is the schematic which shows the 2nd Example of the microfabrication apparatus to which this invention is applied. It is the schematic which shows the 3rd Example of the microfabrication apparatus to which this invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Probe 2 Processing waste 3 Femtosecond laser 4 Femtosecond laser light source 5 Objective lens 6 Sample 7 Protective plate 8 Processing waste 9 Probe rotation mechanism 10 Galvano mirror 11 Cantilever 12 XYZ scanner 13 Laser light 14 Laser light source 15 Quadrant photo detector

Claims (6)

By driving the probe formed at the free end of the cantilever of the atomic force microscope in contact with the excess part of the pattern formed on the sample arranged opposite to the probe, the excess part is obtained. In the fine processing method to remove
A fine processing method comprising irradiating a femtosecond laser to processing waste adhering to a probe after removing an excessive portion, and removing the processing waste by laser ablation.   When irradiating femtosecond laser to the processing waste, a protective plate is arranged between the probe and the sample, and the processing waste removed by the laser ablation is prevented from adhering to the sample. The fine processing method according to claim 1. In a microfabrication apparatus comprising a cantilever in which a probe is formed at the free end of an atomic force microscope, and a driving means for driving the probe by driving the cantilever,
Having femtosecond laser irradiation means for irradiating the probe with a femtosecond laser;
The probe is opposed to a sample having a pattern formed on one main surface, and is driven by being brought into contact with an excess part of the pattern formed on the sample, thereby removing the excess part. A fine processing apparatus characterized by irradiating a femtosecond laser from a femtosecond laser irradiating means to a processing scrap adhering to a probe after removal, and removing the processing scrap by laser ablation.   The femtosecond laser irradiation means is provided so as to irradiate a femtosecond laser from a direction substantially orthogonal to a direction opposite to the sample of the probe, and the sample of the probe after removing a surplus portion 4. The microfabrication apparatus according to claim 3, wherein a processing waste adhering to the probe is removed by irradiating a side surface in a direction substantially orthogonal to the opposite direction with a femtosecond laser.   5. The microfabrication apparatus according to claim 3, wherein a protective plate is disposed on a contact end side to the probe pattern.   The probe has a rotation mechanism that rotates the probe about a direction opposite to the sample as a rotation axis, and irradiates the femtosecond laser while rotating the probe after removing the excess portion, and the probe The fine processing apparatus according to any one of claims 3 to 5, wherein processing waste adhering to the substrate is removed.

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