JPS60116771A - Vapor source device for cluster ion beam - Google Patents

Abstract

PURPOSE:To prevent spitting and to improve film quality by covering the top surface and side face of a hermetic type crucible having a nozzle atop the same with a cylindrical heater and providing an aperture part of a large diameter at the point where the aperture faces the nozzle. CONSTITUTION:A heater which heats a crucible 1 of a hermetic type having a nozzle 4 atop the same in a vacuum chamber 2 is formed of a heater 6 of an approximately cylindrical shape covering the top surface 1b and side surface 1a of the crucible 1. An aperture 10 slightly larger than the nozzle 4 is formed at the point where the aperture faces the nozzle 4. A slit 11 is formed at the point where the slit faces the side face 1a so that heating near the nozzle 4 and the uniform heating over the entire side face 1a are accomplished. When an inside material 7 is melted by heating the crucible 1 with the heater 6, the vapor thereof is ejected from the nozzle 4 and is controlled by an ionizing means 8 and an accelerating means 9 so as to be stuck on a substrate 3 in the form of a thin film. Since the temp. near the nozzle 4 does not fall, the film quality is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an evaporation source device for use in cluster ion beam deposition.

Conventionally, a closed type crucible having a nozzle in a vacuum chamber and a substrate are provided facing each other, and an ionization means made of an ionization filament and an acceleration means made of an extraction electrode are provided between them, and the heating process of the heater is carried out from the crucible. There are known types in which the evaporated material is ejected through a nozzle.

In this type of system, when the evaporated material is ejected from a nozzle, it is supercooled and becomes a beam of a mass of atoms, that is, a cluster beam, and the incident energy of the beam to the substrate is controlled by ionization means and acceleration means. The evaporation speed is fast, the substrate temperature is low, and the film quality remains overnight.As the nozzle is designed to heat the sides, the temperature near the nozzle is low, creating a spitting state in which the evaporated material is spewed out in droplets. This easily results in poor film quality, and if the diameter of the crucible is increased, the temperature near the nozzle further decreases, so there is a drawback that a crucible with a large diameter cannot be used.

An object of the present invention is to provide an evaporation source device for cluster ion beam evaporation that eliminates these drawbacks. The melt is heated with a heater to eject a spontaneous cluster beam from a nozzle, and an ionization means and an acceleration means for the cluster beam are provided between the crucible and the middle part of the substrate. Heater f that heats the body
The upper surface and side surfaces of the crucible are all formed into a substantially cylindrical shape, and a slightly larger opening is provided at a portion facing the nozzle, and the upper surface of the crucible is placed close to the nozzle. It consists of

Embodiments of the present invention will be explained with reference to the drawings. In FIG. 1), which is formed in a sealed shape with a nozzle (4) above it, and placed on a lifting platform (5) and equipped with a heater (6). The structure is such that it can appear freely inside the building.

When the crucible (1) is heated by the heater (6), the substance (7) inside turns into steam and is ejected in the form of a beam onto the substrate (3) through the nozzle (4). When ejected from 4), the evaporated material undergoes adiabatic expansion and becomes supercooled and becomes a beam of lumpy atomic groups, ie, clusters, in which n atoms are loosely bonded to each other. (8) Ionization filament (
8a) and a grid (8b),
(9) shows an accelerating means consisting of an electrode that extracts the beam ionized by the ionizing means (8), that is, cluster ions, toward the substrate (3); both means (8) (9)
) By controlling the kinetic energy of the beam, it is possible to change the deposition rate and form a film at a low substrate temperature, and by controlling the ion acceleration voltage, the film quality can be controlled.

The above configuration is almost the same as that of conventional cluster ion beam evaporation. With this configuration, the temperature near the nozzle (4) is lower than that of the side surface (1a) of (1). There are disadvantages such as a tendency for substances to condense on the nozzle (4) and cause spitting. In the present invention, the heater (6) is made of an electrically resistive material in the shape of an Aa cylinder with the top turned down as shown in the second figure, and the upper surface (1b) of the crucible (1) is
and the side surface (1a), and has an opening slightly larger than the nozzle (4) at the location where the nozzle (4) is sealed.
0f, and a slit Qll was formed at a location opposite to the side surface (]a) to provide uniform heating to the vicinity of the nozzle (4) and to the entire side surface (1a). 5 Heating of the crucible (1) is sometimes done by electron bombardment from electrodes provided on the side of the crucible (1). teeth(
Electrons can be allowed to rush into the side surface (1a) of 1). (6) is a film thickness monitor, θ1 is a temperature controller, a→ is a thermocouple, and αQ is an independent power supply.

To explain its operation, the crucible (1) is its side (1a)
and a heater (6) covering the top surface (1b) heated from K
1 part of substance (7) is dissolved and its vapor is noil (4)
The ionizing means (8) and the accelerating means (9) control the ionizing means (8) and the accelerating means (9) to eject and deposit K in the form of a thin film.
The heater (6) is equipped with a srillet αη or a linear heater on the side, and also covers the upper surface (1b) of the crucible (1), so that a drop in temperature near the nozzle (4) is prevented, and evaporated substances are prevented near the nozzle (4). It is possible to prevent the occurrence of spitting due to condensation.

In this way, according to the present invention, a closed crucible having a nozzle is covered with a cylindrical heater having an opening facing the nozzle and a slit on the side, so that uniform heating of the sides of one crucible can be achieved. The area around the nozzle, which tends to get colder, can be heated.
It is possible to prevent the occurrence of spitting, improve the film quality, and even when using a large-diameter crucible, there is no temperature drop near the nozzle, making it possible to use the furnace as a shed and perform vapor deposition for a long time.

[Brief explanation of drawings]

Fig. 1 is a cut side view of an embodiment of the present invention, and Fig. 2 is a perspective view of an example of the configuration of a heater.・・・
Board (4)...Nozzle (6)j...Heater (8)
...Ionization means (9) ...Acceleration means 00...
Opening (1a)...Side surface (1b)...Top surface

Claims (1)

[Claims] A closed crucible with a nozzle on the upper surface and a substrate are placed in a vacuum chamber facing each other, and the crucible is heated with a heater to eject a cluster beam of evaporated material from the nozzle, and the cluster beam is placed between the crucible and the substrate. In the type provided with an ionization means and an acceleration means, the heater for heating the crucible is formed into a substantially cylindrical shape that covers the top and side surfaces of the crucible, and is also placed at a location opposite to the nozzle. A cluster ion beam evaporation source device that has a somewhat large opening and has its upper surfaces placed nK close to each other.