JP2006161122A - Film deposition system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film deposition system which performs a film deposition by the irradiation of ion beams using ions having specified energy. <P>SOLUTION: A vacuum arc discharge is generated between a cathode 11 and an anode 12, so as to generate plasma composed of carbon ions. Then, the plasma is accelerated toward incidence slit plates 21 by accelerating electrodes 13. Ion beams 25 made incident from slit holes in the incidence slits 21 are deflected by deflection electric fields 26. The ion beams 25 composed of carbon ions having specified energy are converged on the slit holes in the incidence slits 22, and pass through the slit holes in the incidence slits 22, so as to be emitted to a substrate 42 mounted on a substrate stage 41 in a film deposition chamber 4. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a film forming apparatus for forming a film on an object to be formed by irradiating an ion beam.

As a prior art, a film forming apparatus that removes carbon particles that cause film quality degradation from a plasma beam is known (Patent Document 1). In this film forming apparatus, a plasma beam for forming a carbon film on a substrate is passed through a bent toroidal duct wound with a magnetic coil. The electrically neutral carbon particles contained in the plasma beam do not bend along the toroidal duct and travel in a straight line even when a magnetic field is generated by the magnetic coil. For this reason, carbon particles are trapped in the toroidal duct.
Japanese Patent Laid-Open No. 2003-239062

  The film forming apparatus described in Patent Document 1 can remove electrically neutral particles from a plasma beam, and can form a film having a certain degree of film quality. However, it is desired to form a more excellent film.

(1) A film forming apparatus according to the invention of claim 1 includes a plasma generating unit for generating plasma, an accelerating unit for accelerating the plasma by applying a predetermined electric field, and a slit hole for receiving an ion beam from the accelerated plasma. An incident slit plate, an electrostatic prism that bends the trajectory of the ion beam incident from the slit hole of the incident slit plate, and an exit slit plate that includes the slit hole through which the ion beam whose trajectory is bent by the electrostatic prism passes. And a film forming chamber in which an ion beam emitted from the slit hole of the exit slit plate is irradiated onto the film forming object.
(2) The invention of claim 2 is the film forming apparatus according to claim 1, wherein the plasma generator generates plasma using vacuum arc discharge or vaporizes the solid material by resistance heating, The vaporized material is irradiated with an electron beam and charged to generate plasma.
(3) The invention of claim 3 is characterized in that the film forming apparatus according to claim 1 or 2 is configured to form a film of only ions having specific energy.
(4) A fourth aspect of the invention is characterized in that, in the film forming apparatus according to any one of the first to third aspects, carbon ions are generated from a plasma generation unit.

  According to the present invention, a film is formed by irradiating an object to be formed with an ion beam only with ions having a specific energy, that is, ions having a uniform mass and valence. This film can be formed.

  As a result of the inventor's investigation, it has been found that a film having excellent film quality can be formed only with ions having the same energy, that is, mass and valence, in the ion beam. Hereinafter, the film forming apparatus will be described.

  FIG. 1 shows the configuration of a film forming apparatus according to an embodiment of the present invention. The film forming apparatus of FIG. 1 includes a plasma generation unit 1, an ion transfer unit 2, a scanning device 3, and a film forming chamber 4. The film formation chamber 4 is evacuated by a vacuum evacuation device (not shown).

  The plasma generation unit 1 includes a cathode 11, an anode 12, and an acceleration electrode 13. The cathode 11 is made of disk-shaped high purity graphite. A vacuum arc discharge is generated between the cathode 11 and the anode 12 to generate a plasma of carbon ions. The carbon ion plasma is accelerated by an acceleration voltage applied to the acceleration electrode 13 to generate an ion beam.

  The ion transfer unit 2 includes an entrance slit plate 21, an exit slit plate 22, an inner electrode 23, and an outer electrode 21. The entrance slit plate 21 and the exit slit plate 22 are metal plates, and the entrance slit plate 21 and the exit slit plate 22 are formed with elongated rectangular slit holes. The positional relationship between the entrance slit plate 21 and the exit slit plate 22, that is, the deflection angle α is (180 ° / √2), that is, about 127 °. The inner electrode 23 and the outer electrode 24 are formed in a cylindrical surface shape and face each other. The inner electrode 23 and the outer electrode 24 have a coaxial positional relationship, and constitute an electrostatic prism that bends the trajectory of the ion beam 25. A voltage that is negative with respect to the outer electrode 24 is applied to the inner electrode 23, and a deflection electric field 26 that bends the ion beam 25 is generated in the ion transfer unit 2.

  The ion beam 25 incident on the ion transfer unit 2 from the slit hole of the incident slit plate 21 contains carbon ions having various masses and valences. Then, due to the deflection electric field 26, only carbon ions having specific energy, that is, monovalent carbon ions having the same mass converge on the slit holes of the exit slit plate 22. Here, the deflection electric field 26 is adjusted by a voltage applied between the inner electrode 23 and the outer electrode 24 so that only monovalent carbon ions having uniform mass converge on the slit hole of the exit slit 22.

  The scanning device 3 includes, for example, a pair of C-shaped magnetic cores (not shown). The magnetic poles of one magnetic core are arranged up and down in the figure with the exit slit plate 22 in between, and the magnetic poles of the other magnetic core are arranged in a direction perpendicular to the paper surface with the exit slit plate 22 in between. In this case, the ion beam 25 is deflected and scanned in the vertical direction in the figure and in a direction orthogonal to the paper surface.

  A substrate stage 41 is provided in the film formation chamber 4, and a substrate 42 that is a film formation target is mounted on the substrate stage 41. The substrate stage 41 moves in the vertical direction in the figure and in the direction perpendicular to the paper surface so that the film can be formed in a wider area than the area where the ion beam 25 is deflected and scanned by the scanning device 3. be able to. Further, the substrate stage 41 rotates the substrate 42 in the plane so that the film can be uniformly formed.

  Next, the film forming operation will be described. A vacuum arc discharge is generated by applying a voltage of several tens to several hundreds volts between the cathode 11 and the anode 12. When vacuum arc discharge occurs, plasma containing carbon ions having various masses and valences is generated. In addition to carbon ions, clusters composed of many carbon atoms called macroparticles are also emitted. The generated plasma is accelerated toward the entrance slit plate 21 by the acceleration electrode 13. At this time, electrically neutral carbon particles are not accelerated and are removed from the ion beam.

  The ion beam 25 incident from the slit hole of the incident slit plate 21 is deflected by bending the trajectory by the deflection electric field 26. FIG. 2 is a diagram showing trajectories in the ion transfer section 2 of the ion beam 25 composed of carbon ions having various masses and valences. A deflection electric field so that an ion beam 25 composed of carbon ions having a specific energy, that is, monovalent carbon ions having a uniform mass is converged to the slit hole of the exit slit plate 22 as shown in FIG. 26 is adjusted. For this reason, the ion beam 25 composed of carbon ions having specific energy, that is, monovalent carbon ions having a uniform mass, passes almost through the slit holes of the exit slit plate 22. On the other hand, the trajectory of the ion beam 25 composed of carbon ions having no specific energy, such as divalent carbon ions, converges before reaching the exit slit plate 22 as shown in FIG. Diverge again or reach the exit slit plate 22 before converging as shown in FIG. For this reason, the ion beam 25 composed of carbon ions having no specific energy hardly passes through the slit holes of the exit slit plate 22.

  An ion beam 25 composed of ions having specific energy, that is, monovalent carbon ions having a uniform mass, that passed through the slit hole of the exit slit plate 22 was mounted on the substrate stage 41 of the film forming chamber 4. The substrate 42 is irradiated. At this time, the scanning beam 3 is used to deflect and scan the ion beam 25 in the direction orthogonal to the traveling direction, and the substrate stage 41 is moved in the direction orthogonal to the ion beam 25 so that the ion beam is uniformly distributed over a wide region of the substrate 42. 25 can be irradiated.

The film forming apparatus according to the above embodiment has the following effects.
(1) A carbon ion having a specific energy is taken out and a film can be formed mainly using the carbon ion. For this reason, film growth is uniform compared to a conventional film in which carbon ions of various masses and valences are mixed, and film quality control such as hardness and refractive index becomes easy. In addition, a high-quality carbon film that is dense, hard, and excellent in toughness can be produced.
(2) By forming the shapes of the inner electrode 23 and the outer electrode 24 of the ion transfer section 2 with coaxial cylindrical surfaces and adjusting them to a predetermined deflection angle, carbon ions having specific energy can be taken out. The film quality can be easily controlled with the apparatus having such a simple structure.

  In the film forming apparatus described above, plasma is generated by performing a vacuum arc discharge on a disk-shaped high-purity graphite. However, carbon is heated and vaporized, and the vaporized carbon is irradiated with an electron beam to generate plasma. May be. A film forming apparatus in the case where plasma is generated by vaporized carbon will be described with reference to FIG. The configuration of the ion transfer unit 2, the scanning device 3, and the film forming chamber 4 is the same as that of the film forming device of FIG.

  The plasma generation unit 5 includes a crucible 51 around which a coil 55 is wound, a charge supply unit 52, and an acceleration electrode 53. Inside the crucible 51 is stored carbon 54 which is a solid material of the plasma source. An electron beam is emitted from the charge supply unit 52 toward the cathode 56.

  The carbon 54 inside the crucible 51 is heated by resistance by the heating coil 55 and evaporated. The evaporated and vaporized carbon is ionized by the impact of the electron beam irradiated from the charge supply unit 52, that is, is charged and becomes carbon ions. The carbon ions are accelerated toward the incident slit plate 21 by the accelerating electrode 53 and are incident on the ion transfer unit 2 from the slit holes of the incident slit plate 21.

  In the above embodiment, the electrode shape of the inner electrode 23 and the outer electrode 24 of the ion transfer unit 2 is a coaxial cylindrical surface, but may be a concentric spherical surface. In this case, the deflection angle is 180 °, and the shape of the slit hole of the entrance slit plate 21 and the shape of the slit hole of the exit slit plate 22 are both circular.

  In the above embodiment, the film was formed by the ion beam composed of monovalent carbon ions having the same mass. However, the present invention is not limited to the embodiment as long as the carbon ion has specific energy. For example, an ion beam composed of divalent carbon having a uniform mass is configured to converge in the slit hole of the exit slit plate 22 and formed by an ion beam composed of divalent carbon ions having a uniform mass. A membrane may be performed.

  In the above embodiment, the carbon film forming apparatus has been described. However, the present invention is not limited to the carbon film forming apparatus. For example, the present invention can be applied to a silicon film forming apparatus.

The correspondence between the elements of the claims and the embodiments will be described.
The acceleration unit of the present invention corresponds to the acceleration electrode 13, and the electrostatic prism corresponds to the inner electrode 23 and the outer electrode 24. The film formation target corresponds to the substrate 42, and the solid material corresponds to the carbon 54. In addition, the above description is an example to the last, and when interpreting invention, it is not limited to the correspondence of the component of said embodiment and the component of this invention at all.

It is a figure which shows the structure of the film-forming apparatus of this invention. (A) is a figure which shows the trajectory of the ion beam comprised from the carbon ion with specific energy, (b) and (c) are the ion beam comprised from the carbon ion which does not have specific energy FIG. It is a figure which shows the structure of the film-forming apparatus of other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,5 Plasma generation part 11,56 Cathode 12 Anode 13,53 Acceleration electrode 2 Ion transfer part 21 Incidence slit board 22 Outgoing slit board 23 Inner electrode 24 Outer electrode 25 Ion beam 26 Deflection electric field 3 Scanning apparatus 4 Deposition chamber 41 Substrate stage 42 Substrate 51 Crucible 52 Charge supply unit 54 Carbon 55 Heating coil α Deflection angle

Claims (4)

A plasma generator for generating plasma;
An acceleration unit for accelerating the plasma by applying a predetermined electric field;
An incident slit plate provided with a slit hole into which an ion beam by the accelerated plasma is incident;
An electrostatic prism that bends the orbit of the ion beam incident from the slit hole of the incident slit plate;
An exit slit plate having a slit hole through which an ion beam whose orbit is bent by the electrostatic prism passes;
A film forming apparatus comprising: a film forming chamber in which an ion beam emitted from a slit hole of the exit slit plate is irradiated to a film forming object. The film forming apparatus according to claim 1,
The plasma generator generates plasma by generating a plasma using vacuum arc discharge, or vaporizing a solid material by resistance heating, irradiating the vaporized material with an electron beam and charging the material. A characteristic film forming apparatus. In the film-forming apparatus of Claim 1 or 2,
A film forming apparatus configured to form a film only of ions having specific energy. In the film-forming apparatus described in any one of Claims 1 thru | or 3,
A film forming apparatus for generating carbon ions from the plasma generating section.

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