JPH06151392A - Fine processing method and object processed by the method - Google Patents

Abstract

PURPOSE:To provide a simple fine processing method which enables with a size of substantially a probe needle without a backscattering or charge-up phenomenon for electron beams, and without being limited by electron beam wavelengths or the like. CONSTITUTION:The fine processing method comprises a process in which a probe needle 2 having a fine tip 6 and the surface of an object to be processed 1 are contacted with each other by applying a force exceeding a predetermined magnitude between the atomic surface of the tip 6 and the atomic surface of the object to be processed when the distance between the tip 6 and the object surface is substantially zero, and a process for relatively displacing the probe needle 2 and the object to be processed 1 in a direction substantially perpendicular to the direction of application of the force while the force is being applied.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fine processing method,
In particular, molecular manipulation and processing in molecular devices,
The present invention relates to a microfabrication method in ordinary processing of semiconductor devices or micromachines, or pit processing of recording materials.

[0002]

2. Description of the Related Art As a typical conventional fine processing technique, a lithographic technique which is generally used for manufacturing semiconductor devices is known. The processing method using this lithographic technique is to cure or decompose a photosensitive polymer called a resist by irradiating the substrate to be processed with ionizing radiation, to form a pattern on the substrate, and to process the substrate to be processed through development and etching steps. Is the way to do it.

In recent years, a scanning probe microscope has been developed. For example, in 1986, G. F. Quate
And Gh. Atomic Force Micro (AFM), which was named and developed by Gerber
(Phys. Rev. Let)
t 56. (1986) 930), the force acting between the sample and the probe is detected, and the probe is scanned along the surface to form an image of the surface. By scanning the observation surface with the probe of these microscopes, it is possible to observe the unevenness of the atomic plane of the uppermost layer of the observation object.

Further, it has been reported that the adsorptive atoms on the substrate can be rearranged by using a probe tip of a scanning tunneling microscope (STM) which is one of scanning probe microscopes (for example, Japanese Patent Laid-Open No. H03-03242). 238744).

[0005]

In the fine processing method using the lithographic technique, the minimum processing line width depends on the wavelength of the ionizing radiation to be irradiated, and the processing line width is made smaller as the wavelength of the ionizing radiation is shorter. You can Currently about 2
It is possible to process up to a line width of about 200 nm using ultraviolet rays having a wavelength of 00 nm. However, fine line widths smaller than this, for example, line widths at the molecular level are not possible because they are limited by the wavelength.

Further, the conventional fine processing method using the lithography technique has a problem that it has complicated steps such as exposure, development and etching.

It is also known that fine lithography processing with a considerably narrow line width is possible by using an electron beam. However, in lithography processing using an electron beam, even if a narrow line width can be used to process an isolated line, in the case where the line-to-space is 1: 1 the electron beam backscatters about 100 nm. Line width (depending on the substrate material etc.) is the limit. Further, since the electron beam has an electric charge, it causes a phenomenon of resist charge-up, which causes a positional deviation of a drawing pattern. In order to prevent this charge-up phenomenon, there is a problem that it is necessary to apply a conductive film to the substrate to be processed.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art and to limit the wavelength of the electron beam without backscattering and charge-up phenomenon as in the case of using an electron beam. It is an object of the present invention to provide a simple microfabrication method that enables microfabrication with substantially the size of a probe needle without being processed.

[0009]

Generally, when observing a sample with an atomic force microscope (AFM) or the like, a weak force of about 10 ⁻⁹ N to 10 ⁻⁸ N is applied between the sample and the probe. While scanning the sample surface, the repulsive force or the like acting between the atomic surface of the sample and the atomic surface of the probe is detected.

On the other hand, the present invention, on the other hand, is different from the case of operating a conventional atomic force microscope (AFM) or the like, in which a strong force of, for example, 10 ⁻⁸ N to 10 ⁻⁶ N is exerted between the sample and the probe. This is based on the finding discovered by the applicant that the sample can be finely processed by applying a force.

In order to achieve the above-mentioned object, when the distance between the tip and the surface of the workpiece is substantially zero, the tip of the tip having a fine tip and the surface of the workpiece is set to be substantially zero. A step of applying a force exceeding a predetermined magnitude between the atomic plane and the atomic plane of the surface of the workpiece to bring them into contact with each other, and the probe and the workpiece with the force applied. And a step of relatively displacing in a direction substantially perpendicular to the direction of applying the force.

Further, when the processed product is processed, it is preferable that it is removed in units of atoms or molecules, or in units of a small number of aggregates of atoms or molecules. Further, it is preferable that the tip portion has a size of 10 μm or less. The size of the tip portion is preferably 100 nm or less. The size of the tip is 1 nm.
The following is preferable. Further, it is preferable that the processed product has a surface having a regular atomic arrangement.
Further, the processed product is preferably an LB film. Further, it is preferable that the LB film is a polyion complex type LB film. Further, it is preferable that the LB film is made of an amphipathic compound having a polymerizable site. Further, it is preferable that the processed product is composed of an organic thin film.
Further, it is preferable that the method for forming the organic thin film is any one of spin coating, vapor deposition, sputtering, dipping, CVD, and molecular beam epitaxy. Further, it is preferable that the relative displacement between the probe and the workpiece be performed by driving a piezo element. Also,
The processed product is preferably a processed product which is finely processed by this fine processing method. Further, the processed product is preferably a substrate itself or a thin film laminated on a semiconductor substrate or a glass substrate.

[0013]

[Function] When the tip of the probe and the surface of the workpiece are brought close to each other so that the distance between them is substantially zero, there is an interatomic repulsive force between the atomic plane of the tip and the atomic plane of the workpiece surface. Although acting, a force exceeding a predetermined magnitude is applied between the tip of the probe and the surface of the workpiece to bring the tip into contact with the surface of the workpiece. Here, the force having a magnitude exceeding a predetermined magnitude is a force at which molecules or atoms on the surface of the workpiece start to move, and the force at which the surface of the workpiece begins to deform. Next, with this force applied, the probe and the workpiece are relatively displaced in a direction substantially perpendicular to the direction in which the force is applied. As a result, the work piece is cut to a size substantially equal to the size of the tip portion.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a fine processing method according to the present invention will be described with reference to the drawings. As shown in FIG. 3, the probe 2 is held above the workpiece 1 by a holder (not shown) so as to be movable in the Z direction. The workpiece 1 is placed and fixed on a table 3, and the table 3 is movable in X and Y directions. Further, a force of a predetermined magnitude can be applied to the probe 2 from below the table 3 in the Z direction.

FIG. 4 shows an example of the probe 2. The probe 2 has a cantilever 4, a pyramid-shaped base 5 is fixed to the tip of the cantilever 4, and a probe tip 6 is fixed to the tip of the pyramid-shaped base 5. The shape of the probe tip 6 is enlarged and shown in FIG. The probe chip 6 has an aspect ratio of about 10: 1 and a tip radius of curvature of about 200 Å. Note that the probe 2
For example, those manufactured by TopoMetrix or Nanoprobe can be used. Further, as the table 3, the probe 2, and the control device and the detection device thereof, for example, TMX-200SPM (Scanning P) manufactured by the California Institute of Technology is used.
robe Microscope (sold by Nissay Sangyo Co., Ltd.), SPI3700 (manufactured by Seiko Denshi Kogyo), or the like can be used.

As the material of the probe tip 6,
It is possible to use carbon, diamond, silicon, silicon nitride, silicon oxide, or those materials coated with metal or metal oxide.

The work piece 1 is the substrate itself, or a semiconductor substrate such as a silicon substrate or a thin film laminated on a glass substrate. The film forming method of the workpiece 1 includes spin coating (spin coating), vapor deposition, sputtering, dipping, CVD (chemical vapor deposition), or MBE.
Each method of (molecular beam epitaxy) and the LB method can be used. Further, it is preferable that the processed object 1 has a surface composed of a regular atomic or molecular arrangement such as an LB film.

The work piece 1 such as a work film to which the present embodiment can be applied is not limited to the LB film and the like, but also inorganic semiconductors such as silicon, silicon nitride, compound semiconductors such as gallium arsenide, and a coating type silicon oxide film. The organic material may be a high molecular compound such as carbon, novolac cresol, polyvinyl phenol, polymethylmethacrylate (PMMA), polymethylisopropylketone (PMIPK) or a low molecular weight organic compound. In particular, as the LB film, a polyion complex type LB film, an LB film made of an amphipathic compound having a polymerizable site, and the like can be used in addition to the normal LB film made of a fatty acid.

Next, the process of this embodiment will be described. First, the probe 2 is brought close to the workpiece 1 so that the distance between the probe 2 and the surface of the workpiece 1 becomes substantially zero. At this time, between the atomic plane of the probe tip 6 of the probe 2 and the atomic plane of the surface of the workpiece 1, the Lenard-Jones type potential U (r) = 4ε ((σ / r) ¹² − (σ / R)
^As is approximated by ⁶ ), the attractive force due to the dispersive force acts at a long distance, whereas when the distance between the atomic plane of the probe tip 6 and the atomic plane of the surface of the workpiece 1 is substantially zero, P
The interatomic repulsive force by the exclusion rule of auli acts.

Next, the table 3 is pushed up in the Z direction with respect to the probe tip 6 by a force exceeding a predetermined size. Here, the force of a magnitude exceeding a predetermined magnitude is
It is the force that molecules or atoms on the surface of the workpiece 1 start to move,
The force at which the surface of a workpiece begins to deform. The magnitude of this force is usually a higher needle pressure than when observing a sample with an atomic force microscope (AFM) or the like, and is 10 ⁻⁸ N, for example.
To 10 ⁻⁶ N. The magnitude of this force is experimentally set depending on the hardness of the workpiece 1 and the like.

Next, with this force applied, the table 3 is displaced relative to the probe 2 in the desired machining direction in the X and Y planes. This relative displacement is performed, for example, by driving a piezo element. As a result, the surface of the workpiece 1 is ground and finely processed.

According to the configuration of this embodiment, a force exceeding a predetermined magnitude is applied between the atomic plane of the probe tip 6 and the atomic plane of the surface of the workpiece 1 to bring them into contact with each other, and 6 and the workpiece 1 are displaced relative to each other, so that there is no back scattering or charge-up phenomenon as in the case of using an electron beam, and the wavelength of the electron beam is not limited, and the size of the probe needle is substantially the same. It is possible to provide a simple microfabrication method that enables microfabrication according to the size. Therefore, when the probe tip 6 having a tip radius of curvature of about 200 Å is used, fine processing can be performed with a line width of about 200 Å by appropriately setting the applied force. In addition, the probe tip 6
If the diameter of is reduced, microfabrication of a size corresponding to the diameter becomes possible.

The size of the probe tip 6 is about 10.
It may be μm or less, 100 nm or less, and further 1 nm or less.

Next, an example in which the present embodiment is actually applied will be described below. Example 1 Eleven layers of arachidic acid were accumulated on a silicon substrate by the LB method to obtain a uniform film having a film thickness of 27.5 nm. The film surface was then scanned using a commercial atomic force microscope (AFM) to scrape away the film material. Needle pressure 10 ⁻⁷ N, probe tip 6
Has a diameter of about 30 nm. FIG. 2 shows a photograph of an AFM image showing the grain structure before processing. FIG. 1 shows a photograph of an AFM image showing a particle structure after scanning and processing the probe. In FIG. 1, a black square portion is a hole that has been cut and processed. This processed hole is the probe tip 6
Is processed by scanning left and right about 256 times. It can be seen that a hole having a line width of 300 nm is processed. Although not shown here, processing with a smaller line width is also possible.

Example 2 PMMA was spin-coated on a silicon substrate to a film thickness of 50.
A uniform film having a thickness of nm was formed. The film surface was then scanned using a commercial atomic force microscope (AFM) to scrape away the film material.
The needle pressure is 10 ⁻⁶ N, and the diameter of the probe tip 6 is about 30.
nm. A line having a line width of 300 nm could be drawn.

[0026]

As described above, according to the present invention,
Simple and easy to perform fine processing according to the size of the probe needle without backscattering and charge-up phenomenon as in the case of using an electron beam, and without being restricted by the wavelength of the electron beam, etc. It is possible to provide a fine processing method.

[Brief description of drawings]

FIG. 1 is a photograph by an atomic force microscope (AFM) showing a grain structure obtained by finely processing a film in which arachidic acid is formed on a silicon substrate by the LB method by applying the fine processing method according to the present invention. The hole size is about 300 nm.

2 is an atomic force microscope (AFM) photograph corresponding to FIG. 1, showing a particle structure before applying the microfabrication method of the present invention to a film in which arachidic acid is formed on a silicon substrate by the LB method.

FIG. 3 is a diagram schematically showing an apparatus for carrying out the present invention.

FIG. 4 is a diagram showing an example of a probe.

[Explanation of symbols]

 1 Workpiece 2 Probe 3 Table 4 Cantilever 5 Pyramid base 6 Probe tip

Claims (14)

[Claims] 1. An atomic plane of the tip and the workpiece between the probe having a fine tip and the surface of the workpiece when the distance between the tip and the surface of the workpiece is substantially zero. A step of applying a force of a magnitude exceeding a predetermined magnitude to contact with the atomic surface of the surface, and in the state of applying this force, the probe and the workpiece are substantially in the direction of applying the force. And a step of relatively displacing in a perpendicular direction. 2. The microfabrication method according to claim 1, wherein when the workpiece is processed, it is removed in units of atoms or molecules or in units of a small number of aggregates of atoms or molecules. 3. The microfabrication method according to claim 1, wherein the size of the tip portion is 10 μm or less. 4. The microfabrication method according to claim 3, wherein the tip portion has a size of 100 nm or less. 5. The microfabrication method according to claim 4, wherein the size of the tip portion is 1 nm or less. 6. The microfabrication method according to claim 1, wherein the workpiece has a surface having a regular atomic arrangement. 7. The fine processing method according to claim 6, wherein the processed product is an LB film. 8. The LB film is a polyion complex type L
The microfabrication method according to claim 7, which is a B film. 9. The microfabrication method according to claim 7, wherein the LB film is made of an amphipathic compound having a polymerizable site. 10. The microfabrication method according to claim 1, wherein the workpiece is an organic thin film. 11. The organic thin film forming method includes spin coating, vapor deposition, sputtering, dipping, and chemical vapor deposition CV.
The microfabrication method according to claim 10, wherein the method is either D or molecular beam epitaxy. 12. The relative displacement between the probe and the workpiece is
The fine processing method according to claim 1, wherein the fine processing is performed by driving a piezo element. 13. A processed product finely processed by the fine processing method according to claim 1. 14. The fine product according to claim 13, wherein the processed product is a substrate itself or a thin film laminated on a semiconductor substrate or a glass substrate.