JPS60125368A - Vapor deposition device for thin film - Google Patents

Abstract

PURPOSE:To improve ionization efficiency of clusters by disposing a doughnut- shaped magnet on the outside of an ionizing filament with a cluster ion beam vapor deposition device and extending the residence time of the thermion generated from the filament in the cluster beam. CONSTITUTION:A metal 5 for evaporation such as Zn or the like in a crucible 4 is melted by the thermion from a filament 6 and is injected to the surface of a base plate 18 as a cluster beam 17 from the outlet 4a of the crucible in the form of the clusters of Zn vapor so that the Zn is deposited by evaporation on said surface. A magnetic field is impressed in an arrow B direction by a doughnut- shaped magnet 30 provided on the outside of the filament 9 to stagnate long the thermion in the cluster beam 17 in the case of ionizing the Zn clusters by the thermion 13 emitted from the filament 9. The probability at which the thermion 13 collides against the clusters increases and the ionizing efficiency of the clusters is improved.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a thin film deposition apparatus, and particularly to an apparatus that improves cluster ionization efficiency when forming a thin film by cluster ion beam deposition. .

[Prior art]

In general, a thin film deposition method using cluster ion beam deposition involves ejecting the vapor of a substance to be deposited onto a substrate in a vacuum chamber to generate clusters (massive atomic groups) in which many atoms in the vapor are loosely bonded. , showering the cluster with electrons to transform the cluster into cluster ions in which one atom is ionized, and accelerating the cluster ions to collide with a substrate, thereby depositing a thin film on the substrate. It's a method.

Conventionally, as an apparatus for carrying out such a thin film deposition method,
There were those shown in Figures 1 and 2. FIG. 1 is a schematic configuration diagram schematically showing a conventional thin film deposition apparatus, and FIG. 2 is a perspective view showing the inside with a part of the main part thereof cut away. In the figure, 1 is a vacuum chamber maintained at a predetermined degree of vacuum, and 2 is an exhaust passage for evacuating the vacuum N41, which is connected to a vacuum evacuation device (not shown). 3 is a vacuum pulp that opens and closes the exhaust passage 2.

Reference numeral 4 denotes a closed crucible equipped with a nozzle 4a having a diameter of 1 mm to 211,111 mm, in which an evaporated substance to be deposited on the substrate, such as zinc (Zn) 5, is accommodated.

6 is a bombarding filament that irradiates the crucible 4 with thermoelectrons to heat it; 7 is a heat shield plate that blocks radiant heat from the filament 6; The bombardment filament 6 and the heat shield plate 7 form a steam generation source 8 that spouts vapor of a substance to be deposited onto the substrate into the vacuum chamber 1 to generate clusters.

Note that 19 is an insulating support member that supports the heat shield plate 7, and 20 is a support stand that supports the crucible 4.

9 is heated to 2000℃ or more to generate thermionic electrons 1 for ionization.
1 is an ionization filament that emits ionization filament 9, 1O is an electron extraction electrode that accelerates thermoelectrons 13 emitted from ionization filament 9, and 11 is a heat shield plate that blocks radiant heat from ionization filament 9. The electron extraction electrode 10 and the heat shield plate 11 form an ionization means 12 for ionizing the clusters from the steam generation source 8. Note that 23 is an insulating support member that supports the heat shield plate 11.

Reference numeral 14 denotes an acceleration electrode that accelerates the ionized cluster ions 16 and causes them to collide with the substrate 18 together with the unionized neutral clusters 15 to deposit a thin film. Max 10k
Potentials up to V can be applied. In addition, 24 is an accelerating electrode 14
22 is a substrate holder that supports the substrate 18; 21 is an insulating support member that supports the substrate holder 22; 17 is the cluster ion 16 and the neutral cluster 15;
It is a cluster beam consisting of.

Next, the operation will be explained.

To explain the case of depositing a zinc i film on the substrate 18, first fill the inside of the roof 4 with zinc 5, Create a vacuum of about 10 Torr inside.

Next, the bombardment filament 6 is energized to generate heat, and the radiant heat from the bombardment filament 6 or thermionic electrons emitted from the filament 6 are caused to collide with the crucible 4, that is, by electron (Ii bombardment).
The zinc 5 in the crucible 4 is heated and evaporated. When the inside of the Lupo 4 is heated to a temperature (500°C) at which the vapor pressure of the zinc 5 is about 0.1 to 10 Torr, the metal vapor ejected from the nozzle 4a is Due to the difference, the atoms expand adiabatically, forming a mass of atoms called a cluster, in which many atoms are loosely bonded.

This cluster-shaped cluster beam 17 collides with thermionic electrons 13 extracted from the ionization filament 9 by the electron extraction electrode 10, so that one atom of some of the clusters is ionized and becomes a cluster ion 16. Become. This cluster ion 16 is
The non-ionized neutral clusters 15 are accelerated by the electric field formed between the crucible 4 and the electron extraction electrode 10, and collide with the substrate 18 with the kinetic energy of the unionized neutral clusters 15 ejected from the crucible 4. 18, which causes a thin zinc film to be deposited on the substrate 18.

However, in this conventional thin film deposition apparatus, the thermionic electrons for ionization quickly cross the cluster beam and stay in the beam for a short time, so the probability of collision between the clusters and thermionic electrons is small, and the ionization of the clusters is reduced. There was a drawback that it was not carried out efficiently.

(Summary of the Invention) This invention was made to eliminate the drawbacks of the conventional ones as described above, and it applies a magnetic field to the thermoelectrons extracted by the electron extraction electrode in a direction substantially perpendicular to the direction of their emission. The object of the present invention is to provide a thin film deposition apparatus that can lengthen the residence time of electrons in a cluster beam and improve ionization efficiency by causing the thermoelectrons to undergo a spiral motion.

(Embodiments of the invention) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows a thin film deposition apparatus according to an embodiment of the present invention,
In the figure, 1. The same reference numerals as in FIG. 2 indicate the same parts. Reference numeral 30 denotes a donut-shaped magnet as a magnetic field generating means added in this embodiment, which surrounds the outside of the arc-shaped filament 9 and is pulled out in the direction of arrow B, that is, from the filament 9 toward the cluster beam bundle 17. 10 W in a direction almost perpendicular to the radiation direction of the thermionic electrons 13
b/n? A magnetic field of I to 10 Wb/nl is applied.

Next, the operation will be explained.

In the device of this embodiment, thermionic electrons 13 are extracted from the ionization filament 9 by the electron extraction electrode lO, the extracted thermionic electrons 13 are applied with a magnetic field by the magnet 30 to perform a spiral motion, and are then irradiated onto the cluster. As a result, one atom of some of the clusters from the steam generation fi8 is ionized to become cluster ions 16. During this ionization process, the thermoelectrons 13 stay in the cluster beam 17 for a long time, increasing the probability of collision between the thermoelectrons and the cluster.
Clusters can be ionized efficiently.

In this way, in this example device, a donut-shaped magnet is arranged outside the arc-shaped filament, and the electron extraction electrode draws out the thermoelectrons from the filament toward the center of the cluster beam, which is almost perpendicular to the radiation direction. Since the magnetic field is applied in the direction, the thermoelectrons can perform spiral motion and stay in the cluster beam for a long time, making it possible to efficiently ionize the clusters.

In the above embodiment, one donut-shaped magnet was placed outside the filament, but a large number of bar magnets may be placed at predetermined positions on the circumference outside the filament, as shown in FIG. In many cases, the same effects as in the above embodiment can be achieved.

Further, in the case of another embodiment of the present invention shown in FIG. 5, in which a pair of filaments and an electron extraction electrode are arranged facing each other so as to sandwich the cluster beam, one of the four sides surrounding the cluster beam is A pair of bar magnets may be arranged facing each other on the two surfaces where the filament and the electron extraction electrode are not arranged, and the same effects as in the above embodiment can be obtained.

In addition, in the above embodiment, a cluster ion beam device was described in which a crucible is heated by electron bombardment to generate clusters, but the present invention injects room temperature gas such as silane (SiH4) into a vacuum chamber from a gas storage chamber having a nozzle. The present invention may also be applied to a Clask ion beam device that generates clusters, and the same effects as those of the above-mentioned embodiments can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, a magnetic field is applied to the thermionic electrons in a direction substantially perpendicular to the direction of their emission, causing the thermionic electrons to move in a spiral manner. This has the effect of improving ionization efficiency.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a conventional thin film deposition apparatus, FIG. 2 is a perspective view showing the inside of the vacuum chamber, and FIG. 3 is a perspective view showing the inside of the vacuum chamber of a thin film deposition apparatus according to an embodiment of the present invention. FIG. 4 is a sectional view showing the inside of a vacuum chamber according to another embodiment of the present invention, and FIG. 5 is a perspective view showing the inside of a vacuum chamber according to still another embodiment of the present invention. l...Vacuum chamber, 5...Substance to be deposited (zinc), 8
...Steam source, 9...Filament, 10...
Electron extraction electrode, 14... Accelerating electrode, 15... Neutral cluster, 16... Cluster ion, 18...
Substrate, 30... magnet (magnetic field generating means). Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Masuo Oiwa 1 M Figure 2 Figure 3 Figure 4 Continued from page 1 ■Inventor Hasayuki Iwatani Tsukaguchi Ichiichi. 8-1-1, 1-cho, Mitsubishi Electric Co., Ltd. Procedural amendment (voluntary) 1. Indication of the case Japanese Patent Application No. 58-235568 3, Part 5 of the person making the amendment, Representative Kata Yuhito, Column 6 of the detailed explanation of the invention in the specification subject to the amendment, Contents of the amendment + 11, Specification page 9, No. 9 Correct "room temperature gas" in the row to "gaseous compound". that's all

Claims (1)

[Claims] (11) A vacuum chamber maintained at a predetermined degree of vacuum, and a cluster in which a large number of atoms in the vapor are loosely bonded by spouting vapor of a substance provided in the vacuum chamber and to be deposited onto a substrate into the vacuum chamber. a filament that emits thermionic electrons to ionize the cluster; an electron extraction electrode that emits the thermionic electrons toward the cluster ejected from the steam generation source; a magnetic field generating means that applies a magnetic field in a direction substantially perpendicular to the radiation direction to cause the thermoelectrons to move in a spiral manner;
A thin film deposition apparatus comprising an acceleration electrode that accelerates ions and causes them to collide with a substrate together with non-ionized neutral clusters to deposit a thin film.