JP2006291328A - Electron beam auxiliary irradiation laser ablation film deposition apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser ablation film deposition apparatus capable of forming a thin film with a good film quality, by suppressing evaporation of a liquefied material when using an arbitrary solid material and suppressing production of particulates in solid target ablation. <P>SOLUTION: The electron beam auxiliary irradiation laser ablation film deposition apparatus is equipped with a target holder 10 which holds the target 11, a substrate holder 20 which holds a substrate 21 for film deposition, an electron beam generator 30 which generates an electron beam, an electron beam-converging device 40 and a laser irradiation device 50. The electron beam-converging device 40 forms an electron lens to converge the electron beam generated by the electron beam generator 30 on a part of the surface of the target 11 and locally liquefies the part of the surface. The laser irradiation device 50 irradiates a laser beam onto the part of the surface of the target 11 liquefied by the electron beam-converging device 40 to perform ablation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a laser ablation film forming apparatus, and more particularly to a laser ablation film forming apparatus that irradiates a laser beam with a target in a liquid state.

  Conventionally, a laser ablation film forming method is known as a method for forming a thin film on a substrate. The laser ablation film forming method has many merits such as high film uniformity and high adhesion strength. However, the laser ablation film forming method using a solid target is difficult to put into practical use because there is a problem that fine particles are generated and taken into the thin film.

  As a method for avoiding such a problem, a method is known in which ablation is performed by irradiating a laser beam in a state where the target is heated and liquefied by a method such as resistance heating (for example, see Patent Document 1). When laser light is irradiated in a liquefied state, fine particles are not generated, so that the fine particles are hardly taken into the thin film. This method is effective for materials having a low melting point and a low vapor pressure such as gallium.

Similarly, an apparatus for performing laser ablation by irradiating a laser beam to a heat-melted target is also known (see, for example, Patent Document 2).
JP-A-4-311561 JP 2002-241930 A

  However, in the case of a material such as silicon (Si) having a relatively high melting point and a high vapor pressure in the molten state, the amount of vapor evaporated from the target in the liquid state increases. The amount of the vapor that adheres to the substrate reaches a level that cannot be ignored as compared to the amount of the laser ablation. Since the film quality of the thin film formed by the adhesion of the vapor is inferior to the film quality of the thin film formed by laser ablation, the film quality of the formed thin film is deteriorated as a result.

  Therefore, the present invention provides a laser ablation film forming method that suppresses components caused by evaporation of a liquefied material with respect to an arbitrary solid material, and does not generate fine particles in the solid target ablation, and thus can form a thin film with good film quality. An object is to provide an apparatus.

  To achieve the above object, the present invention provides a target holder that holds a target made of a solid material, a substrate holder that is provided at a predetermined position with respect to the target holder, and that holds a film-forming substrate, and an electron beam. An electron beam generating device that generates the electron beam and an electron lens to converge the electron beam generated from the electron beam generating device onto a part of the surface of the target, thereby locally irradiating a part of the surface of the target There is provided an electron beam auxiliary irradiation laser ablation film forming apparatus provided with an electron beam converging apparatus that liquefies and a laser light irradiation apparatus that irradiates a part of the surface of the liquefied target with laser light.

  Here, the electron beam auxiliary irradiation laser ablation film forming apparatus further includes a vacuum container having a vacuum chamber, and the electron beam generator applies an electron beam emission source and a voltage to the electron beam emission source to apply electrons. It is preferable that the target power source, the substrate holder, and the electron beam emission source are provided in the vacuum chamber.

  The target holder includes a bottom portion and a peripheral wall standing from the bottom portion so as to surround the target. The bottom portion and the peripheral wall form a concave portion that accommodates the target. A first wall portion positioned on the laser beam irradiation device side; and a second wall portion positioned on the opposite side of the laser beam irradiation device, the first wall portion and the second wall portion. Each preferably has an open end inclined toward the bottom side toward the inside of the recess.

  The drive power supply preferably includes an electron beam moving means for moving the convergence position of the electron beam on the surface of the target. Furthermore, it is preferable that the laser beam irradiation apparatus includes a laser beam moving unit that moves the irradiation position of the laser beam on the surface of the target. The target holder preferably includes a cooling means for cooling and holding the target.

  Further, a closed state is provided between the target holder and the substrate holder and prevents the target evaporant from reaching the substrate, and an open state that allows the target evaporant to reach the substrate. It is preferable to provide a shutter that can be switched between. The vacuum vessel is preferably provided with an observation window for observing the electron beam convergence position and the laser beam irradiation position on the surface of the target.

  According to the electron beam auxiliary irradiation laser ablation film forming apparatus of claim 1, the electron beam converging device locally liquefies a part of the surface of the target, and the laser beam irradiation device of the target liquefied surface of the target. Since a part is irradiated with laser light, there is no problem that fine particles are generated unlike the laser ablation film forming method using a solid target. Moreover, since the entire target is not liquefied, but a part of the target surface is locally liquefied, even if the target is made of a material such as silicon (Si) having a high vapor pressure in the liquid state, the liquid is liquefied. The amount of vapor that evaporates from the deposited part is very small. That is, the amount of such vapor deposited on the substrate is negligible compared to the amount deposited by laser ablation. Therefore, the thin film formed by this apparatus has many merits characteristic of the laser ablation method, such as good uniformity and high adhesion strength. In addition, according to the present apparatus, even when the target is a low-melting-pressure material having a low melting point such as aluminum or a sublimable material having a high melting point, a thin film having good film quality can be formed. That is, it is possible to form a thin film having a good film quality by a laser ablation method with respect to an arbitrary solid material.

  According to the electron beam auxiliary irradiation laser ablation film forming apparatus according to claim 2, since the target holder, the substrate holder, and the electron beam emission source are provided in the vacuum chamber, laser ablation can be effectively performed. .

  According to the electron beam auxiliary irradiation laser ablation film forming apparatus according to claim 3, the first wall portion located on the laser beam irradiation apparatus side has an opening end portion inclined toward the bottom side toward the inside of the recess. The laser beam can be incident from an oblique direction. Therefore, it is possible to prevent the problem that it is difficult for the laser beam to be incident on the target because the substrate holder becomes an obstacle. In addition, the second wall portion located on the opposite side of the laser beam irradiation device also has an opening end portion inclined toward the bottom side toward the inside of the concave portion, so that it is reflected by the surface of the liquefied target. The laser beam passes without being irradiated to the second wall portion. Since the liquefied target may be evaporated and attached to the second wall, the problem of ablating the adhering substance to which the reflected laser light is applied to prevent unnecessary fine particles from attaching to the deposition substrate is prevented. can do.

  According to the electron beam auxiliary irradiation laser ablation film-forming apparatus according to claim 4, since the electron beam moving means for moving the electron beam convergence position on the surface of the target is provided, the electron beam convergence position is adjusted on the surface of the target. It can be moved to an appropriate position.

  According to the electron beam auxiliary irradiation laser ablation film forming apparatus according to claim 5, the laser light irradiation apparatus is provided with the laser light moving means for moving the irradiation position of the laser light on the surface of the target. Laser light can be irradiated to an appropriate position on the surface of the target.

  According to the electron beam auxiliary irradiation laser ablation film forming apparatus according to claim 6, since the target holder includes a cooling means for cooling and holding the target, only a part of the surface of the target is liquefied locally, Other portions can be prevented from becoming liquid as much as possible. Therefore, the amount of vapor evaporated from the liquefied portion can be further suppressed.

  An electron beam auxiliary irradiation laser ablation film forming apparatus according to an embodiment of the present invention will be described with reference to FIGS.

  First, the configuration of an electron beam auxiliary irradiation laser ablation film forming apparatus 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. As shown in FIG. 1, an electron beam auxiliary irradiation laser ablation film forming apparatus 1 includes a vacuum vessel 6, a target holder 10, a substrate holder 20, an electron beam generator 30, an electron beam converging device 40, and a laser. And a light irradiation device 50.

  A vacuum chamber 61 is defined inside the vacuum vessel 6. The vacuum vessel 6 is provided with a vacuum device (vacuum pump) 65, and the vacuum chamber 61 can be evacuated to be in a vacuum state. As shown in FIG. 1, the target holder 10, the substrate holder 20, the filament 31 described later among the electron beam generator 30, the electron beam converging device 40, and the like are provided in the vacuum chamber 61.

  The target holder 10 is for holding the target 11 made of a solid material. As shown in FIGS. 1 and 2, the target holder 10 includes a bottom portion 12 (FIG. 2) and a peripheral wall 13 erected from the bottom portion 12 so as to surround the target 11. The peripheral wall 13 has an upper surface 13A. The bottom portion 12 and the peripheral wall 13 form a concave portion 16 having a substantially circular shape in a plan view that accommodates the crucible 17 holding the target 11.

  As shown in FIG. 2, the peripheral wall 13 has a first wall portion 14 located on the laser light irradiation device 50 side and a second wall portion 15 located on the opposite side of the laser light irradiation device 50. is doing. That is, the first wall portion 14 and the second wall portion 15 constitute a part of the peripheral wall 13. The first wall portion 14 has an open end portion 14 </ b> A that is inclined toward the bottom portion 12 toward the inside of the recess 16. Similarly, the second wall portion 15 has an opening end portion 15 </ b> A that is inclined toward the bottom portion 12 toward the inside of the recess 16. Open end portions 14A and 15A constitute a part of upper surface 13A. Therefore, as shown in FIG. 2, the upper surface 13A is inclined from the outer peripheral side toward the concave portion 16, and has a shape like a part of a conical surface.

  As shown in FIG. 1, the target holder 10 is provided with a water cooling device 18, and the crucible 17 and the target 11 can be cooled and held. As shown in FIG. 1, since the target holder 10 is connected to ground, the target holder 10, the crucible 17, and the target 11 are all at ground potential. The vacuum vessel 6 is also at ground potential.

  The substrate holder 20 is for holding the film-forming substrate 21 for forming a thin film. In the present embodiment, the substrate holder 20 is provided above (+ Z direction) about 10 cm away from the target 11. The substrate holder 20 has an opening 20 a, and the film formation surface 21 </ b> A of the film formation substrate 21 is exposed toward the target 11. Therefore, the substance evaporated from the target 11 is deposited on the film formation surface 21A through the opening 20a. In FIG. 1, the substrate holder 20 and the film formation substrate 21 are shown in a cross section along a direction perpendicular to the film formation surface 21A.

  A shutter 71 is installed between the substrate holder 20 and the target holder 10. The shutter 71 is configured to be openable and closable. In the opened state, the substance evaporated from the target 11 is allowed to reach the film-forming substrate 21. In the closed state, the substance evaporated from the target 11 is applied to the film-forming substrate 21. Stop reaching.

  The electron beam generator 30 includes a filament 31 and an electron beam generating drive power supply 32. The filament 31 is made of, for example, a tungsten filament, and emits free electrons when a current flows. The electron beam generating drive power supply 32 is for applying a negative potential to the filament 31 and for supplying a current for heating the filament 31. The electron beam generating drive power supply 32 includes an AC power supply 33, a DC power supply 34, coils L1 to L3, capacitors C1 and C2, and a remote control device 35.

  The voltage V of the AC power supply 33 is variable by the remote operation device 35 as will be described later. The AC power source 33 is connected to the coil L1. The coils L1 to L3 constitute one insulating transformer as a whole. As indicated by the points attached to the coils L1 to L3 in FIG. 1, the polarities of the coils L2 and L3 are equal to each other, and the polarities of the coils L2, L3 and the coil L1 are opposite to each other. The inductances of the coils L2 and L3 are equal to each other. Capacitors C1 and C2 have the same capacity.

  One of the DC power supplies 34 is connected to the ground, and the other is connected between the capacitors C1 and C2 and between the coils L2 and L3. The voltage E of the DC power supply 34 is variable in the range of 0 to −8 kV (kilovolts) by the remote control device 35. The electron beam generator 30 is connected to an ammeter (not shown) for measuring the current flowing through the filament 31.

  The remote operation device 35 includes a power switch 35P, a control knob 35A, and a control knob 35B. The power switch 35 </ b> P is a switch for turning on / off the power source of the electron beam generator 30. The control knob 35A is a knob for adjusting the voltage E of the DC power supply 34. The control knob 35B is a knob for adjusting the voltage V of the AC power supply 33. In the electron beam generator 30, the filament 31 is provided in the vacuum chamber 61, but the electron beam generating drive power supply 32 is provided outside the vacuum vessel 6.

  The electron beam converging device 40 includes a permanent magnet 41, yokes 42 and 43, and an anode 44. The yokes 42 and 43 are made of steel and are provided on both sides of the permanent magnet 41, respectively. The permanent magnet 41 and the yokes 42 and 43 have a substantially “U” shape as a whole, and thus form a magnetic field H (FIG. 4) similar to a horseshoe magnet.

  The anode 44 has a substantially flat plate shape, and a through hole 44a penetrating in the vertical direction (Z-axis direction) is formed in the middle thereof. As shown in FIG. 2, the anode 44 is provided so that the through hole 44 a is located above the filament 31 (+ Z direction). As shown in FIG. 1, the anode 44 is connected to the ground.

  The laser light irradiation device 50 includes a laser device 51, a lens 52, and a moving device 53. The laser device 51 is a commercially available pulse laser device capable of generating pulsed laser light having a desired wavelength, intensity, and frequency. The lens 52 is a lens for condensing the laser beam emitted from the laser device 51 and irradiating the target 11. In this embodiment, a quartz lens having a focal length of 500 mm is used. The moving device 53 is connected to the lens 52 and can translate the lens 52 in the XYZ axial directions. By performing such movement, the irradiation position of the laser beam on the surface of the target 11 can be moved. The laser device 51, the lens 52, and the moving device 53 are provided outside the vacuum vessel 6.

  A laser window 63 is provided on the wall of the vacuum vessel 6, and the laser beam emitted from the laser device 51 and condensed by the lens 52 can be transmitted. A shutter 72 configured to be openable and closable is provided in the vacuum chamber 61 and between the laser window 63 and the target 11. The shutter 72 is closed except during the laser beam irradiation, and suppresses the gaseous component evaporating from the heated target 11 from adhering to the laser window 63.

  Further, a target observation window 62 is provided on the wall of the vacuum vessel 6 so that the state of the target 11 can be observed from the outside. A shutter 73 configured to be openable and closable is provided in the vacuum chamber 61 and between the target observation window 62 and the target 11. Since the shutter 73 is closed except during the target observation, it is possible to suppress the gas component evaporating from the heated target 11 from adhering to the target observation window 62.

  Next, a film forming method using the above-described electron beam auxiliary irradiation laser ablation film forming apparatus 1 will be specifically described with reference to FIGS. FIG. 3 is a flowchart showing steps (hereinafter referred to as “S”) S10 to S50 in the film forming method. 4 and 5 show a state in which film formation is performed by the electron beam auxiliary irradiation laser ablation film formation apparatus 1.

  As shown in FIG. 3, in S <b> 10, as a preparation, the target 11 is horizontally installed in the target holder 10, and the cleaned film formation substrate 21 is fixed to the substrate holder 20. In this embodiment, a disk-shaped silicon having a diameter of 20 mm, a thickness of 5 mm, and a purity of 99.999% is used as the target 11. Further, a square quartz glass plate having a thickness of 0.5 mm and a side of 1 cm is used as the film formation substrate 21.

In S20, the vacuum vessel 6 is evacuated by the vacuum device 65 to be in a vacuum state higher than about 3 × 10 ⁻⁶ torr. At this time, the shutters 71 to 73 are kept closed. The target holder 10 is cooled by the water cooling device 18.

  In S30, the target 11 is irradiated with an electron beam. The power switch 35P of the remote control device 35 shown in FIG. 4 is turned on. The control knob 35B is turned to adjust the voltage V of the AC power supply 33, and the intensity of the electron beam D emitted from the filament 31 is adjusted to about 20 mA (milliamperes). Since the amount of electrons emitted increases as the current flowing through the filament 31 increases, the electron beam emitted from the filament 31 is adjusted by adjusting the voltage V of the AC power supply 33 to adjust the value of the current flowing through the filament 31. The intensity of D can be adjusted.

  Here, the shutter 73 is opened and the target 11 is observed from the target observation window 62 to confirm that a partial region of the surface of the target 11 is in a liquid state. This region is called a liquid region 11A. The liquid region 11A has, for example, a substantially elliptical shape with a size of about 3 mm × 5 mm. As will be described later, since the convergence position of the electron beam D can be adjusted by adjusting the voltage E of the DC power supply 34, the voltage E of the DC power supply 34 is adjusted by turning the control knob 35A while observing the target 11. Then, the convergence position of the electron beam D is moved near the center of the liquid region 11A.

  Here, a mechanism in which the electron beam generating drive power supply 32 applies a negative potential to the filament 31 and a current for heating the filament 31 is supplied will be described. When current from the AC power supply 33 flows through the coil L1, induced electromotive force is generated in the coils L2 and L3. As described above, since the polarities and inductances of the coils L2 and L3 are the same, induced electromotive forces having the same direction and size are generated in the coils L2 and L3, respectively, and AC voltages obtained by adding these electromotive forces to both ends of the filament 31. Is applied. The filament 31 is given a low potential with respect to the ground by the voltage E of the DC power supply 34. From the above, an AC voltage centered on the potential −E (minus E) and having an amplitude corresponding to the voltage of the AC power supply 33 is applied to the filament 31. Since the capacitors C1 and C2 have a function of smoothing the AC voltage applied to the filament 31, the potential of the filament 31 can be made more stable.

  Next, a mechanism for adjusting the convergence position of the electron beam D by changing the voltage E of the DC power supply 34 will be described. As described above, a potential of about −E is applied to the filament 31 and a ground potential is applied to the anode 44. Therefore, an electric field is applied between the filament 31 and the anode 44 due to the difference between the potential −E and the ground potential. The potential of the anode 44 is the ground potential as with the target holder 10 and the vacuum vessel 6. As described above, the electrons emitted from the filament 31 are accelerated upward (in the + Z direction) by this electric field. Since the through hole 44a of the anode 44 is located above the filament 31 (FIG. 2), most of the electrons pass through the through hole 44a and reach the upper side of the anode 44. Here, when the velocity of the electrons when reaching the position above the anode 44 is v, the velocity v increases as the value of the voltage E increases.

  On the other hand, a magnetic field H is generated by the permanent magnet 41 and the yokes 42 and 43. An electron having a velocity v receives a force F expressed by F = −e · v × B in a magnetic field having a magnetic flux density B. Here, e is the charge amount of electrons, v and B are both vectors, • is a scalar product, and x is a vector product. That is, the electrons receive a force F directed in a direction perpendicular to both the direction of the velocity v and the direction of the magnetic field of the magnetic flux density B. Therefore, the electrons are bent by a distance corresponding to the magnitude of the force F. As described above, the speed v increases as the value of the voltage E of the DC power supply 34 increases. Therefore, by adjusting the voltage E, the convergence position of the electron beam D can be adjusted. As described above, the electron beam converging device 40 converges and emits the electrons emitted from the filament 31 onto the liquid region 11A by the electron lens effect of an electric field and a magnetic field.

  In S40, the laser device 51 is driven to generate pulsed laser light having a wavelength of about 193 nm, an intensity of about 190 mJ / pulse, and a pulse frequency of 50 Hz. The shutter 72 is opened, and the laser light R condensed by the condenser lens 52 is incident on the liquid region 11A and irradiated. The irradiation pattern of the focused laser beam on the surface of the target 11 has a size of about 2 mm × 0.4 mm. Since the liquid is thinner at the end of the liquid region 11A, the laser light R is irradiated near the center where the liquid has a depth of about 100 μm or more. Otherwise, a part of the laser beam R may reach the solid portion of the target 11 to generate fine particles.

  Further, irradiation is performed while moving the lens 52 by the moving device 53 and changing the irradiation position. This is because, if the laser beam R is irradiated only at the same position, a hole is dug due to the viscosity of the liquid, the liquid layer becomes thin, and the laser beam R reaches the solid portion, resulting in generation of fine particles. Specifically, the irradiation position of the laser beam R is periodically moved on the liquid region 11A along the longitudinal direction (Y direction) of the liquid region 11A at a constant speed of amplitude ± 2 mm and 0.25 mm / second. Go back and forth. As described above, in order to prevent the generation of fine particles, the depth of the liquid region 11A is preferably about 100 μm or more. However, this depth varies depending on the intensity of the laser beam R, the wavelength of the laser beam R, the material of the target 11, and the like.

  In S50, the shutter 71 is opened to start film formation on the film formation substrate 21, and after about 10 minutes, the shutter 71 is closed and the film formation ends.

  The effect of the shape of the target holder 10 according to the present embodiment will be described with reference to FIG. As shown in FIG. 5, the laser beam R is irradiated at an angle of about 60 degrees with respect to the direction perpendicular to the surface of the target 11 (Z-axis direction). At this time, since the opening end portion 14A is inclined toward the bottom portion 12 toward the inside of the concave portion 16, the laser light R is irradiated to the liquid region 11A of the target 11 without being blocked by the first wall portion 14. The Further, since the opening end 15 </ b> A on the opposite side is also inclined toward the bottom 12 toward the inside of the recess 16, the laser light R ′ reflected by the liquid region 11 </ b> A is also blocked by the second wall 15. Without being emitted to the outside of the recess 16. Accordingly, the reflected laser beam R ′ is applied to the inner wall of the second wall portion 15, and the substance evaporated and adhered to the inner wall is ablated, so that unnecessary fine particles adhere to the deposition substrate 21. Does not occur.

  When a film formation experiment was actually performed by the above method, a high-quality silicon film having a thickness of 50 nm and no fine particles having a size of 10 nm or more, which was observable by a scanning electron microscope (SEM), was obtained. I was able to. Further, an experiment was conducted in which the cellophane tape was peeled off after the cellophane tape was adhered to the silicon film, but the silicon film was not peeled off. For further comparison, an experiment was conducted to determine how much film thickness can be formed only by electron beam irradiation without performing laser beam irradiation. It was found that it was negligible at 1/100 or less compared with the thickness.

  As described above, according to the electron beam auxiliary irradiation laser ablation film forming apparatus 1 according to the present embodiment, the electron beam converging device 40 locally liquefies a part of the surface of the target 11 and the laser light irradiation device 50 Since the liquid region 11A of the target 11 is irradiated with the laser beam R, there is no problem that fine particles are generated unlike the laser ablation film forming method using a solid target. Moreover, in order to locally liquefy part of the target surface instead of liquefying the entire target 11, even when the target 11 is a material such as silicon (Si) having a high vapor pressure in the liquid state, The amount of vapor evaporating from the liquid region 11A is very small. That is, the amount of such vapor deposited on the substrate is negligible compared to the amount deposited by laser ablation. Therefore, the thin film formed by the electron beam auxiliary irradiation laser ablation film forming apparatus 1 according to the present embodiment has many merits characteristic of the laser ablation method, such as good uniformity and high adhesion strength. Yes. In addition, according to the present apparatus, even when the target is a low-melting-pressure material having a low melting point such as aluminum or a sublimable material having a high melting point, a thin film having good film quality can be formed. That is, it is possible to form a thin film having a good film quality by a laser ablation method with respect to an arbitrary solid material.

  Further, since the target holder 10 includes a water cooling device 18 for cooling and holding the target 11, only a part of the surface of the target 11 is liquefied locally by irradiation with an electron beam (liquid region 11A), It is possible to prevent liquefaction by suppressing the temperature rise in other parts as much as possible. Therefore, the amount of vapor evaporated from the liquefied portion can be further suppressed.

  Next, as a comparative example, a case where target holders 110 and 210 having a shape different from that of the target holder 10 are used will be described with reference to FIGS. 6 (a) and 6 (b). In general, it is known that the evaporated substance generated from the target is released in proportion to cos θ (θ is an angle formed by the direction in which the substance is released with respect to the direction perpendicular to the liquid surface). Therefore, the evaporated substance is released with a spread centering on the direction (+ Z direction) from the target 11 toward the film formation substrate 21. For this reason, in order to prevent the evaporating substance traveling in a direction other than the direction of the film formation substrate 21 from adhering to the inner wall of the vacuum vessel 6, as shown in FIG. It is desirable to install in a deep position.

  On the other hand, since there is the substrate holder 20 above the target 11, it is necessary to make the laser beam incident while avoiding the substrate holder 20. For this reason, the target holder 110 and the substrate holder 20 become an obstacle, and there arises a problem that it is difficult to put the laser light into the crucible 17. In the example shown in FIG. 6A, a part of the laser beam R is blocked by the substrate holder 20.

  In order to solve this problem, as shown in FIG. 6B, the opening end 214A of the target holder 210 may be formed obliquely, and the laser light R may be incident more obliquely. However, since the liquid region 11A has a mirror surface with no irregularities, most of the incident laser light R is reflected by the mirror surface. The reflected laser beam R ′ irradiates the inner wall of the target holder 210 with almost no spread, ablating the substance evaporated and adhered from the target 11, and deposits unnecessary fine particles on the deposition substrate 21. This is because the laser beam that has hardly spread is large in energy and has a large ablation force.

  Therefore, as described based on FIG. 5, in the above-described embodiment, the reflection-side opening end portion 15A is formed in addition to the incident-side opening end portion 14A. Therefore, the reflected laser beam R ′ is irradiated to the inner wall of the vacuum vessel 6 in a state of being spread to some extent without being blocked by the second wall portion 15. The energy of the spread reflected laser beam R ′ is relatively small, and the amount of the evaporated substance adhering to the inner wall of the vacuum vessel 6 is smaller than the amount of the evaporated substance adhering to the inner wall of the target holder 10. Can be prevented.

  The electron beam auxiliary irradiation laser ablation film-forming apparatus according to the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made within the scope described in the claims. For example, although silicon is used as the target 11 in the above-described embodiment, any solid material such as a low melting point low vapor pressure material such as aluminum or a high melting point sublimation material can be used.

  In the embodiment described above, the crucible 17 and the recess 16 of the target holder 10 are formed in a substantially circular shape in plan view in accordance with the shape of the target 11. However, the shape of the target 11, the crucible 17, and the recess 16 may be other shapes such as a rectangular shape.

  As described above, the electron beam assisted irradiation laser ablation film forming apparatus according to the present invention is useful as a film forming apparatus capable of forming a thin film having a good film quality by laser ablation with respect to an arbitrary solid material. Is particularly useful when it is a material such as silicon having a high vapor pressure in the liquid state.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which shows the whole structure of the electron beam auxiliary irradiation laser ablation film-forming apparatus by embodiment of this invention. Sectional drawing along the II-II line of FIG. The flowchart which shows each process in the film-forming method using the electron beam auxiliary irradiation laser ablation film-forming apparatus by embodiment of this invention. Explanatory drawing which shows a mode that it forms into a film with the electron beam auxiliary irradiation laser ablation film-forming apparatus by embodiment of this invention. The schematic sectional drawing which shows the effect by the shape of the target holder used for the electron beam auxiliary irradiation laser ablation film-forming apparatus by embodiment of this invention. The schematic sectional drawing which shows the shape of the target holder by a comparative example. The schematic sectional drawing which shows the shape of the target holder by another comparative example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Target holder, 11 ... Target, 11A ... Liquid area | region, 12 ... Bottom part, 13 ... Perimeter wall, 14 ... 1st wall part, 15 ... 2nd Wall part, 14A, 15A ... Open end part, 16 ... Recess, 17 ... Crucible, 18 ... Water cooling device, 20 ... Substrate holder, 21 ... Substrate for film formation, 30 ..Electron beam generator, 31 ... filament, 32 ... drive power source for generating electron beam, 33 ... AC power source, 34 ... DC power source, 35 ... remote control device, 35P ... Power switch, 35A, 35B ... control knob, 40 ... electron beam converging device, 41 ... permanent magnet, 42, 43 ... yoke, 44 ... anode, 44a ... through hole, 50 ..Laser beam irradiation device, 51... Laser device, 52... Lens, 53... Moving device, 60... Vacuum container, 61. 63 ... laser window, 65 ... vacuum device, 71-73 ... shutter, 110, 210 ... target holder, C1, C2 ... capacitor, L1-L3 ... coil.

Claims (6)

A target holder for holding a target made of a solid material;
A substrate holder that is provided at a predetermined position with respect to the target holder and holds a film-forming substrate;
An electron beam generator for generating an electron beam;
An electron beam converging device that converges an electron beam generated from the electron beam generating device onto a part of the surface of the target by forming an electron lens, and thereby partially liquefies the surface of the target; ,
A laser beam irradiation apparatus for irradiating a part of the surface of the liquefied target with a laser beam;
An electron beam auxiliary irradiation laser ablation film forming apparatus comprising: A vacuum vessel provided with a vacuum chamber;
The electron beam generator includes an electron beam emission source, and a driving power source that applies a voltage to the electron beam emission source to emit an electron beam,
The electron beam auxiliary irradiation laser ablation film-forming apparatus according to claim 1, wherein the target holder, the substrate holder, and the electron beam emission source are provided in the vacuum chamber. The target holder includes a bottom portion and a peripheral wall erected from the bottom portion so as to surround the target,
The bottom and the peripheral wall form a recess for accommodating the target,
The peripheral wall has a first wall portion located on the laser light irradiation device side and a second wall portion located on the opposite side of the laser light irradiation device,
3. The electron beam assist according to claim 1, wherein each of the first wall portion and the second wall portion has an opening end portion inclined toward the bottom side toward the inside of the concave portion. Irradiation laser ablation deposition system.   The electron beam auxiliary irradiation laser ablation film forming apparatus according to any one of claims 1 to 3, further comprising an electron beam moving means for moving a convergence position of the electron beam on the surface of the target.   5. The electron beam auxiliary irradiation laser ablation according to claim 1, wherein the laser light irradiation apparatus includes laser light moving means for moving a laser light irradiation position on the surface of the target. Deposition device.   6. The electron beam auxiliary irradiation laser ablation film forming apparatus according to claim 1, wherein the target holder includes a cooling unit for cooling and holding the target.

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