JPH05279844A - Laser abrasion device - Google Patents

Abstract

PURPOSE:To remove granular lumps mixed in the process of film forming and to form a thin film of high gravity by irradiating the space between electrodes with positive electric potential provided at the side face of the space between a target and a substrate holder with a laser beam and removing granular lumps whose electric potential has been charged up into negative one. CONSTITUTION:A target 7 set in a vacuum tank 5 is irradiated with a laser beam 2. A pair of plate electrodes 9b are set between the target 7 and a substrate holder 8. Its space is irradiated with a laser beam 2. By the laser beam 2, the substances in the target 7 are beaten out, and the ions, neutral atoms, granular lumps or the like of the constituting substances of the target 7 are formed to form a thin film on the surface of a substrate 13. At this time, in the case, e.g. 1KV is impressed on an electrode 9a by a power source 14, the granular lumps whose electric potential has been charge up into a negative on by plasma generated on the target 7 by the laser irradiation are absorbed into the electrode 9a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser ablation apparatus used for forming films such as superconductors and ferroelectrics used in thin film devices.

[0002]

2. Description of the Related Art A conventional laser ablation device will be described below.

In the conventional laser ablation apparatus, when a work piece placed in a vacuum chamber is irradiated with a laser beam having an energy density higher than a threshold value, a substance jumps out and adheres this substance to a substrate. A laser generally irradiates a short-wavelength pulsed laser beam with a high energy density.

[0004]

However, in such a method, since the workpiece is locally heated to a high temperature in a short time, molten agglomerates (generally called droplets) of several μm or less pop out. However, since this is mixed in the thin film, there is a problem that a smooth surface which is a basic condition of the thin film device cannot be obtained.

In view of the above problems, the present invention is directed to a laser ablation apparatus which does not reach the substrate by electrically adsorbing or repelling the agglomerates generated during laser light irradiation. For the purpose of providing.

[0006]

In order to solve the above-mentioned problems, the present invention provides a laser oscillator, a lens for condensing a laser beam, a vacuum chamber, and a laser entrance window provided in the vacuum chamber. It is equipped with a target in the vacuum chamber to be irradiated with laser and a substrate holder on the target, and vaporizes by laser light irradiation between positive potential electrodes provided on the side surface between the target and the substrate holder. It is a laser ablation device that allows the target material to pass through.

[0007]

With this configuration, the agglomerates having a negative potential due to the plasma generated by the laser irradiation can be removed and the agglomerates mixed in the thin film can be removed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, for example, a laser beam 2 oscillated from an excimer laser 1 is condensed by a lens 3, passes through a vacuum sealing window 4, and enters a vacuum chamber 5. A vacuum exhaust pump 6 is attached to the vacuum chamber 5. The laser light 2 is applied to the target 7 installed in the vacuum chamber 5. A pair of flat plate electrodes 9a and 9b of, for example, 20 mm × 80 mm are installed between the target 7 and the substrate holder 8, and pass through between the electrodes 9a and 9b, for example, 20 mm, and are placed at the center of the electrodes 9a and 9b. The laser light 2 is irradiated.

In such a structure, for example, 1.5 mm × 2 on the target 7 by the cylindrical lens 3.
The substance of the target 7 is knocked out by the laser beam 2 focused to 0 mm, and as shown in FIG. 2, ions 10, neutral atoms 11, agglomerates 12, etc. of the substance constituting the target 7 are generated, and the substrate 13 A thin film is formed on. At this time, when, for example, +1 KV is applied to the electrode 9 from the power source 14, the agglomerates 12 charged to a negative potential by the plasma 15 generated on the target by laser irradiation are adsorbed to the electrode 9.

Although the electrodes 9 are a pair of flat plates, the same effect can be obtained if they are cylindrical. Next, a second embodiment of the present invention will be described.

FIG. 3 shows a second embodiment, for example, a laser beam 2 oscillated from an excimer laser 21.
The light 2 is condensed by the lens 23, passes through the vacuum sealing window 24, and enters the vacuum chamber 25. A vacuum exhaust pump 26 is attached to the vacuum chamber 25. The laser light 22 is applied to a target 27 installed in the vacuum chamber 25. The substrate holder 28 is electrically insulated from the vacuum chamber 25.

In such a structure, the substance of the target 27 is knocked out on the target 27 by the lens 23, for example, by the laser beam 22 focused to 1.5 mm × 2 mm. From the power supply 29 to the substrate holder 28
When 100 V is applied, the agglomerates 31 charged to a negative potential by the plasma 30 generated on the target by laser irradiation are repelled in the vicinity of the substrate holder 28.

Next, a third embodiment of the present invention will be described. FIG. 4 shows a third embodiment. For example, a laser beam 42 oscillated from an excimer laser 41 is condensed by a lens 43, passes through a vacuum sealing window 44, and enters a vacuum chamber 45. .. The vacuum tank 45 is provided with a gas inlet 46 and a vacuum exhaust pump 47. Laser light 42
Is irradiated on the target 48 installed in the vacuum chamber 45. The substrate holder 49 is electrically insulated from the vacuum chamber 45.

In such a structure, the substance of the target 48 is knocked out on the target 48 by the lens 43 and by the laser beam 42 condensed to, for example, 1.5 mm × 2 mm. When, for example, 13.56 MHz is applied to the substrate holder 49 from the high frequency power supply 50 and oxygen gas is supplied from the gas inlet 46, oxygen plasma 51 is generated around the substrate holder 49. Further, the agglomerates 53 charged to a negative potential by the plasma 52 generated on the target by the laser irradiation are repelled by the plasma sheath 54 of the substrate holder 49.

Next, a fourth embodiment of the present invention will be described. FIG. 5 shows a fourth embodiment, which is
The plasma generating means around the substrate holder 49 is largely different from that of the third embodiment. A microwave radiating means 55 is provided near the substrate holder 49.

Next, a fifth embodiment of the present invention will be described. FIG. 6 shows a fifth embodiment. For example, laser light 62 oscillated from an excimer laser 61 is condensed by a lens 63, passes through a vacuum sealing window 64, and enters a vacuum chamber 65. .. A vacuum exhaust pump 66 is attached to the vacuum chamber 65. The laser light 62 is applied to the target 67 installed in the vacuum chamber 65. An insulating substrate 69 is attached to the substrate holder 68. The electron beam generation source 70 can irradiate the substrate 69 with the electron beam 71.

In such a structure, the substance of the target 67 is knocked out on the target 67 by the lens 63 by the laser beam 62 condensed to, for example, 1.5 mm × 2 mm. At this time, for example, when the electron beam 71 is applied to the entire substrate 69 with a pulse of 10 Hz, the substrate 69 is charged up to a negative potential. The agglomerates 73 charged up to a negative potential by the plasma 72 generated on the target by the laser irradiation are repelled in the vicinity of the substrate 69.

[0019]

According to the laser ablation apparatus of the present invention, by generating an electric field between the target and the substrate, the agglomerates having a negative potential due to the plasma generated by the laser irradiation are removed, and It was possible to remove the agglomerates mixed in the powder, and to form a high quality thin film on the substrate.

[Brief description of drawings]

FIG. 1 is a sectional view of a laser ablation device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of the same operation.

FIG. 3 is a sectional view of the laser ablation device according to the second embodiment.

FIG. 4 is a sectional view of a laser ablation device according to the third embodiment.

FIG. 5 is a sectional view of a laser ablation device according to the fourth embodiment.

FIG. 6 is a sectional view of a laser ablation device according to a fifth embodiment.

[Explanation of symbols]

 1 Excimer laser 2 Laser light 3 Lens 4 Window 5 Vacuum chamber 7 Target 8 Substrate holder 9 Electrode

Claims (11)

[Claims] 1. A laser oscillator, a lens for condensing laser light, a vacuum chamber, a laser entrance window provided in the vacuum chamber, a target in the vacuum chamber and irradiated with laser, and the target. A laser ablation device comprising: a substrate holder above; and a target substance evaporated by laser light irradiation passes between positive potential electrodes provided on a side surface between the target and the substrate holder. 2. The laser ablation device according to claim 1, wherein the laser oscillator is an excimer laser. 3. The laser ablation device according to claim 1, wherein the positive potential electrode has a cylindrical shape. 4. The laser ablation apparatus according to claim 1, wherein the positive potential electrode is a pair of flat plates arranged on the side surface of the target. 5. The laser ablation device according to claim 4, wherein the laser beam is focused so as to form a strip shape in a direction parallel to the pair of plate electrodes. 6. A laser oscillator, a lens for condensing a laser beam, a vacuum chamber, a laser entrance window provided in the vacuum chamber, a target in the vacuum chamber and irradiated with laser, and the target. A laser ablation device equipped with a substrate holder above and means for applying a negative potential to the substrate holder. 7. A laser oscillator, a lens for condensing a laser beam, a vacuum chamber, a laser entrance window provided in the vacuum chamber, a gas inlet, a gas exhaust port, and inside the vacuum chamber. A laser ablation device capable of generating plasma in the vicinity of a substrate holder, comprising a target irradiated with a laser, a substrate holder on the target, and means for applying high frequency to the substrate holder. 8. The high frequency is 13.56 MHz.
The laser ablation device described. 9. A laser oscillator, a lens for converging laser light, a vacuum chamber, a laser entrance window provided in the vacuum chamber, a gas inlet, a gas exhaust port, and inside the vacuum chamber. A laser ablation device that includes a target irradiated with a laser, a substrate holder on the target, and microwave generation means, and is capable of generating plasma in the vicinity of the substrate holder. 10. The laser ablation device according to claim 9, wherein the microwave is 2.45 GHz. 11. A laser oscillator, a lens for condensing laser light, a vacuum chamber, a laser entrance window provided in the vacuum chamber, a target in the vacuum chamber and irradiated with laser, and the target. An upper substrate holder, and an insulating substrate attached to the substrate holder,
A laser ablation device comprising an electron beam generation source and means for irradiating the substrate with the electron beam, and capable of negatively charging up the substrate.