JP2906485B2 - Thin film production equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) In order to form a superconducting thin film, a method of irradiating a target of a superconducting material with a laser beam to evaporate the superconducting material and deposit it on a substrate is used. The present invention relates to an apparatus for producing such a thin film.

(Prior Art) By irradiating a substrate with a laser beam by the above-described method of forming a superconducting thin film, the substrate can be cleaned,
It is known that a good result can be obtained by promoting the migration of a deposited film, and an apparatus for irradiating a substrate with a laser beam has been proposed. An example of such a proposed device is such that a laser beam F is divided into two light beams by a beam splitter S as shown in FIG. 6, and one of the two light beams is irradiated on a target T and the other is irradiated on a substrate B. Things.

(Problems to be Solved by the Invention) In the conventional apparatus shown in FIG. 6, a laser for target irradiation and a laser for substrate irradiation are separated by a beam splitter.
It is necessary to build a large optical system outside the chamber,
In addition, since a number of mirrors are used, the loss due to the mirrors and the absorption of light by the atmosphere are large, the utilization efficiency of the laser is reduced, and the effect of laser irradiation cannot be sufficiently obtained. Therefore, a laser with a large output is required.

The present invention uses a single laser to devise the position and shape of the shutter, which has been used to shield the volatile matter from the target, and to give the shutter a function with partially different light transmission characteristics. It is an object of the present invention to provide a thin film deposition apparatus having good light use efficiency.

(Means for Solving the Problems) A semi-transmissive light reflecting plate is provided so as to be able to enter and exit in an optical path between a target and a laser in a vapor deposition chamber, and a laser reflected when the plate is advanced into the optical path. The beam was incident on the substrate.

(Operation) Since a semi-transparent plate is disposed in the vapor deposition chamber, a mirror that carries light so that one of the light beams is incident on the substrate after the laser beam is split into two is unnecessary, and the loss of laser light is small. ,
Since an optical path for carrying one of the divided light beams is not formed outside the evaporation chamber, the apparatus can be made compact.

(Embodiment) FIG. 1 shows an apparatus according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a vapor deposition chamber, T denotes a target, and B denotes a substrate placed above the target so as to face the target. L denotes a laser, which irradiates a target T with a laser beam through a window 11 of the evaporation chamber. Reference numeral 2 denotes a rotating shaft that is vertically set in the vapor deposition chamber, and has a fan-shaped plate 3 fixed to the upper end thereof, which can be rotated by a motor 4. As shown in FIG. 2, the sector plate 3 has a semi-transparent portion 3h, a total reflection portion 3a, and a transmission window on a circumference centered on the rotation center.
3t are provided, and by rotating the shaft 2, any one of these three portions is transmitted from the laser L to the target T.
Can be located in the optical path of the laser beam emitted toward. The fan-shaped plate 3 has a semi-transparent portion 3h and a total reflection portion 3
The substrate B is irradiated with the reflected laser light when a is placed in the laser beam. The translucent portion 3h may have a mesh structure in which a large number of light transmitting holes are arranged on the total reflection surface, or may be a translucent plate. The semi-transparent portion 3h of the sector plate is notched at the periphery so as not to prevent the evaporating substance from the target T from being sputtered toward the substrate. The interposition between T and the substrate B prevents the deposition material from flying between the target and the substrate.

The operation of actually depositing a thin film with the above-described apparatus is performed in the following order. First, as shown in FIG. 3A, the sector plate 3 is turned so that the total reflection portion 3a is located in the optical path of the laser beam, and the laser L is operated. With this operation, the substrate B is cleaned by being irradiated with the laser beam. Next, as shown in FIG. 3B, the fan-shaped plate is turned so that the transmission window 3t is positioned in the laser beam optical path, and the target T is irradiated with the laser beam to perform pre-sputtering. Thus, the cleaning of the target surface is performed. At this time, the evaporating substance from the target is blocked by the fan-shaped plate 3 and the substrate B is not contaminated. Finally, as shown in FIG. 3C, the semi-transparent portion 3h of the fan-shaped plate is positioned in the laser beam path, and the laser is operated. At this time, a part of the laser beam
Is reflected to promote the migration of the deposition material,
The other part irradiates the target T to evaporate the target material.

FIG. 4 shows a case where a mask M for regulating the divergence range of the evaporating substance from the target is provided above the target in the above embodiment, and the composition of the evaporating substance from the target is at the periphery of the evaporating substance divergence area and at the center. If not, the peripheral portion is prevented from being deposited on the substrate to form a thin film having a non-uniform composition, and at the same time, the target evaporating substance is prevented from adhering to the lower surface of the sector plate 3.

Since cleaning of the substrate B and laser light irradiation for promoting migration need to be performed over the entire deposition range,
The laser beam needs to be expanded, and the target irradiation needs to focus the laser beam to promote evaporation. Therefore, a condenser lens is inserted between the laser and the target, but before that, the laser light irradiating the substrate B is also focused. In the above example, the laser beam reflected toward the substrate B is diverged by making the upper surfaces of the total reflection surface 3a and the semi-transmissive portion 3h convex, but the evaporating substance from the target is centered in a direction perpendicular to the target surface. Since the target evaporates into a certain solid angle, the target surface is tilted as shown in FIG. 5, and the substrate B is placed at a position deviated from the laser beam focusing point with the substrate B facing the tilted target T. You may do so.

(Effect of the Invention) Since the vapor deposition apparatus of the present invention divides the light of one laser beam into the target and the substrate by providing a semi-transmissive reflecting plate in the vapor deposition chamber so as to be able to enter and exit in the optical path of the laser beam. It does not require a mirror or the like for diverting the laser beam, so that the loss of light is small and the device is small because the light beam is not diverted, and there is no need to secure a detour optical path. Not too limited.

In addition, by making the characteristics of the plate that enters and exits the optical path of the laser beam interchangeable between total reflection and semi-transmission, the substrate can be easily cleaned in addition to promoting the migration of the substance deposited on the substrate.

[Brief description of the drawings]

1 is a side view of an apparatus according to an embodiment of the present invention, FIG. 2 is a plan view of a sector plate in the embodiment, FIG. 3 is a view showing each stage of operation of the apparatus in the embodiment, and FIG. FIG. 5 is a side view of a main part of another embodiment of the present invention, FIG.
FIG. 6 is a side view of a conventional example. 1 ... Evaporation chamber, 2 ... Rotation axis, 3 ... Sector plate, 3a ... Total reflection part, 3h ... Semi-transparent part, 3t ... Transmission window, 4 ... Motor, B ... Substrate, T …… Target, L …… Laser, M
……mask.

Claims (2)

(57) [Claims] 1. An apparatus for irradiating a target with a laser beam to deposit a target material on a substrate, wherein a semi-translucent plate is provided in an optical path of a laser beam incident on the target in a deposition chamber. A thin film characterized in that when the plate is advanced into the optical path, a part of the laser beam light of the optical path reflected by the semi-translucent plate is provided so as to be able to enter and exit with a tilt such that it enters the substrate. Creating device. 2. An apparatus for irradiating a target with a laser beam to deposit a target material on a substrate, wherein a semi-transparent plate and a total reflection plate are provided in an optical path of the laser beam incident on the target. When the semi-transparent plate and the total reflection plate are allowed to enter and exit alternately and both the semi-transmission plate and the total reflection plate are advanced into the optical path, the laser beam light of the optical path reflected by these semi-transmission plates or the total reflection plate is reflected. A thin film forming apparatus, wherein the film is provided at an inclination such that the light is incident on the substrate.