JPH05247633A - Laser abrasion device - Google Patents

Abstract

PURPOSE:To provide a laser abrasion device used in forming the film of a superconductor, ferroelectric, etc., to be utilized for a thin-film device and capable of taking only the ion out of the local plasma produced when the device is irradiated with a laser beam. CONSTITUTION:A laser oscillator 1, a lens 3 for condensing a laser beam 2, a vacuum vessel 5, a laser beam inlet window 4 set in the vessel 5, a target 7 to be irradiated with a laser beam in the vessel 5 and a substrate holder on the target 7 are provided to the device. Consequently, only the ion generated by the laser beam irradiation is deposited on a substrate 9, and the granular lump occluded in the thin film is removed.

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 the substance to a substrate. A laser generally irradiates a short-wavelength pulsed laser beam with a high energy density.

[0004]

However, in such a structure, since the workpiece is locally heated to a high temperature in a short time, molten agglomerates (generally called droplets) of several μm or less are formed. It pops out, and because this mixes in the thin film,
There is a problem that a smooth surface, which is a basic condition of thin film devices, cannot be obtained.

In view of the above problems, the present invention provides a laser ablation apparatus capable of extracting only ions from a local plasma (generally referred to as plasma plume) generated when a laser beam is irradiated to reach a substrate. The purpose is to

[0006]

To achieve the above object, a laser ablation apparatus of the present invention comprises a laser oscillator, a lens for condensing laser light, a vacuum chamber,
A laser incident window provided in the vacuum chamber, a target in the vacuum chamber to be irradiated with laser, and a substrate holder on the target, and a pair of electrostatic deflection electrodes provided on the target. A means for irradiating a laser beam is provided between them.

[0007]

With this structure, only the ions generated by laser irradiation are attached to the substrate to remove the agglomerates mixed in the thin film.

[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 cylindrical 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 fan-shaped electrostatic electrode 8 having a rotation angle of 60 ° and a rotation radius of 36.5 mm is installed on the target 7, so that the laser beam 2 is irradiated to the center of the electrode through a slit formed in the electrode. Has become.

In such a structure, the cylindrical lens 3 is used, for example, 1.5 mm × on the target 7.
Target 7 by laser light 2 focused on 20 mm
2 is knocked out, and as shown in FIG. 2, ions 10, neutral atoms 11 and agglomerates 12 of the constituent material of the target 7 are generated, and a thin film is formed on the substrate 9. At this time,
When -35V is applied to the outer electrode 8a of the electrostatic electrode 8 from the power source 13 and -70V is applied to the inner electrode 8b from the power source 14,
As shown in FIG. 2, only 10 ion components reach the substrate 9. FIG. 3 shows the results of mass spectrometry of ions plunging into the substrate 9 when SrTiO ³ is used as the target 7.

Next, a second embodiment of the present invention will be described. FIG. 4 shows a second embodiment, and this embodiment is different from the first embodiment in the method of irradiating the target 7 with the laser light 2. Laser light 2 is electrostatic electrode 1
It is irradiated from the side of 5.

[0012]

According to the laser ablation apparatus of the present invention, an electric field is generated in the vicinity of the target so that only ions generated by laser irradiation reach the substrate. Therefore, the agglomerates ejected from the target can be removed, and a film can be formed only with the high-energy ion component, and a high-quality thin film can be formed 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 diagram showing a mass distribution result of the same ion.

FIG. 4 is an operation explanatory diagram of the second embodiment of the present invention.

[Explanation of symbols]

 1 Excimer laser 2 Laser light 3 Cylindrical lens 4 Window 5 Vacuum chamber 7 Target 8 Electrostatic electrode 9 Substrate

Claims (3)

[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 including a substrate holder above and irradiating a laser beam between a pair of electrostatic deflection electrodes provided on a target. 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 laser beam is focused so as to form a strip shape in a direction parallel to the electrostatic deflection electrode.