JPH06172985A - Thin film forming device - Google Patents

Abstract

PURPOSE:To provide a thin film forming device capable of preventing the spitting of the droplet of a vapor-deposition material and to reduce its cost by simplifying the structure of the device. CONSTITUTION:A substrate 11 and a crucible 2 filled with a vapor-deposition material 3 are arranged in a vacuum vessel 1, the crucibel 2 is heated to inject the vapor from a nozzle 2a, an atomic ion 3d ionized by hitting a thermoelectron against an unionized neutral atom 3b and a cluster 3a of atoms, and a cluster 3c of ions are accelerated by an electric field and collided with the substrate 11 surface along with the neutral atom 3b and cluster 3a to form a thin film. In this film forming device, a filament 14 surrounding the crucible 2 is formed with a heating part for emitting a thermoelectron to be collided with the crucible 2 and an ionized part for emitting a thermoelectron to hit the atom 3b and cluster 3a, and a power is supplied to the filament 14 from one AC power source 41.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film forming apparatus for forming a thin film on a surface of a substrate by a cluster ion beam method.

[0002]

2. Description of the Related Art FIG. 3 is a schematic view showing a conventional thin film forming apparatus known from Japanese Patent Publication No. 54-9592. In the figure, 1 is a vacuum chamber maintained at a predetermined vacuum degree, 2 is a crucible arranged inside the vacuum chamber 1, 2a is a nozzle of the crucible 2, 3 is a vapor deposition substance filled in the crucible 2, 3a is a vapor deposition substance 3. The vapor of the vapor deposition material 3 is the nozzle 2
Atoms ejected from a that did not form a cluster, 3c are cluster ions ionized by applying thermoelectrons to the cluster 3a, 3d are atomic ions ionized by applying thermoelectrons to the atom 3b, and 4 are made to collide with the crucible 21. A bombarded filament that emits thermoelectrons 5 is a bombarded filament 4
A heat shield that shields the heat of the, 3 is the cluster 3a and the atom 3
an ionizing filament that emits thermoelectrons applied to b, 7
Is a grid for extracting and accelerating thermoelectrons from the ionizing filament 6; 8 is a heat shield for shielding the heat of the ionizing filament 6; 9 is an accelerating electrode for accelerating the cluster ions 3c with an electric field to give kinetic energy; 10 is a vacuum chamber 1, a vacuum exhaust system for exhausting 1, a substrate on which a thin film of the vapor deposition material 3 is formed by vapor deposition on a surface, a first AC power source for supplying electric power to the bombard filament 4, a reference numeral 22 for the crucible 2 to the bombard filament 4 The first DC power supply biasing the potential of the ionization filament 23, the second AC power supply 23 for supplying electric power to the ionization filament 6, 24 the grid 7 for the ionization filament 6
On the other hand, the second DC power supply biases the positive electrode to a positive potential, and the third DC power supply 25 biases the acceleration electrode 9 to a negative potential with respect to the grid 7.

The conventional thin film forming apparatus is constructed as described above, and the vacuum chamber 1 is evacuated by the vacuum evacuation system 10 until a predetermined degree of vacuum is reached. The first AC power supply 21, the first DC power supply 22, the second AC power supply 23, the second DC power supply 24, and the third DC power supply 25 are activated, and the thermoelectrons emitted from the red-hot bombarded filament 4 are generated by the electric field with the crucible 2. To accelerate and collide with the crucible 2 to heat it. As a result, the vapor deposition material 3 with which the crucible 2 is filled is melted and evaporated, and the vapor is ejected from the nozzle 2a and agglomerated in a supercooled state due to adiabatic expansion to form clusters 3a of a cluster of atomic atoms, and a part of the atoms is dispersed. Keep the state. When the thermoelectrons emitted from the ionized filament 6 are accelerated and applied to the clusters 3a and the atoms 3b by the electric field of the grid 7, some of them are ionized to be cluster ions 3c and atomic ions 3d. Non-ionized neutral cluster 3a
And the atoms 3b are ejected from the nozzle 2a, and the cluster ions 3c and the atomic ions 3d are accelerated by the electric field of the accelerating electrode 9 and are given kinetic energy, so that they are both attached to the substrate.
A film is formed by bombarding the surface of 11.

[0004]

The conventional thin film forming apparatus is constructed as described above, and has a bombard filament 4 for heating the crucible 2, a heat shield 5 for shielding the heat, an ionizing filament for ionizing the clusters 3a and the atoms 3b. 6 and a heat shield 8 for shielding its heat, and a grid 7 for extracting and accelerating thermoelectrons from the ionized filament 6.
Since the structure is complicated, the cost is high, and when the bombard filament 4 is heated, the nozzle 2a
The temperature of the central portion of the vapor deposition substance 3 becomes low, the vapor of the vapor deposition material 3 becomes droplets there, and spouting is generated by the pressure of the vapor, and fine particles recrystallized into a thin film formed by vapor deposition on the surface of the substrate 11 are generated. There was a technical problem that the film quality deteriorates when mixed.

The present invention has been made to solve the above problems, and provides a thin film forming apparatus which can simplify the structure and reduce the cost, and which does not generate droplets of a vapor deposition substance. The objective is to obtain a thin film forming apparatus capable of forming a high quality thin film by vapor deposition under optimal conditions by controlling the generation amounts of clusters and atoms and the generation amounts of cluster ions and atomic ions. With the goal.

[0006]

In the thin film forming apparatus according to the present invention, a substrate and a crucible filled with a vapor deposition substance are placed inside a vacuum chamber maintained at a predetermined vacuum degree, and the crucible is heated by collision of thermoelectrons. Then, vapor of the vapor deposition material is ejected from the nozzle of the crucible, and atomic ions and cluster ions ionized by applying hot electrons to the atoms of the vapor deposition material and the clusters of atoms aggregated in the supercooled state by adiabatic expansion are generated in the electric field. In the case of accelerating and bombarding the surface of the substrate with neutral atoms and clusters that do not ionize to form a thin film of a vapor deposition material, a heating part that emits thermoelectrons that cause a filament arranged surrounding the crucible to collide with the crucible. And an ionization part that emits thermoelectrons that hit the clusters and the atoms ejected from the nozzle, and power is supplied to the filament from a single AC power source. It is intended.

Further, electric power is supplied to each of the heating portion and the ionizing portion of the filament from one AC power source.

[0008]

In the thin film forming apparatus constructed as described above, the filaments surrounding the crucible are supplied with electric power from one AC power source, and the thermoelectrons emitted from the heating portion heat the crucible to generate the ionization portion. The emitted thermoelectrons ionize the clusters and atoms.

Further, the heating portion and the ionizing portion of the filament are respectively supplied with electric power from one AC power source, the thermoelectrons emitted from the heating portion heat the crucible, and the thermoelectrons emitted from the ionizing portion ionize the clusters and atoms. To do.

[0010]

【Example】

Example 1. FIG. 1 is a schematic diagram showing an embodiment of the present invention. In the figure, 1, 2, 2a, 3, 3a, 3b, 3
c, 3d, 10, 11, 22, and 25 are the same as those described in the related art. Reference numeral 14 denotes a filament that surrounds the crucible 2 and is composed of a heating portion that emits thermoelectrons that collide with the crucible 2 and an ionization portion that emits thermoelectrons that hit the atoms and clusters. 15 is a heat shield that shields the heat of the filament 14, 19a and 19b are electric field lenses formed by both, and accelerate the cluster ions 3c and atomic ions 3d to give kinetic energy. 41 is an electric power to the filament 14. It is an AC power supply for supplying.

The embodiment of the present invention is constructed as described above, and the vacuum chamber 1 is evacuated by the vacuum evacuation system 10 until a predetermined vacuum degree is reached. The AC power source 41, the first DC power source 22, and the third DC power source 25 are activated to accelerate the thermoelectrons emitted from the heated portion of the filament 14 which is red-hot by the electric field with the crucible 2 and collide with the crucible 2 to heat it. . By this heating, the vapor deposition material 3 with which the crucible 2 is filled is melted and evaporated, and the vapor is ejected from the nozzle 2a and adiabatic expansion causes a supercooled state to agglomerate to form a cluster 3a of a lumped atomic population, and a part thereof Atom 3b
Keep the state of. When the thermoelectrons emitted from the ionized portion of the filament 14 are accelerated and applied to the clusters 3a and the atoms 3b by the electric field with the crucible 2, some of them are ionized to become cluster ions 3c and atomic ions 3d. These cluster ions 3c and atomic ions 3d are accelerating electrodes 19a and 19b.
Neutral cluster 3 which is accelerated by the electric field lens formed by the
Both a and the atom 3b are ejected from the nozzle 2a and collide with the surface of the substrate 11 to form a thin film. According to this embodiment, the thermoelectrons emitted from the ionized portion of the filament 14 are applied to the clusters 3a and the atoms 3b to partially ionize them, so that the structure is simplified and the nozzle 2 of the crucible 2 is used.
Since a is sufficiently heated, droplets of the vapor deposition material are not generated in the central portion of the nozzle 2a, and spitting can be prevented.

Example 2. FIG. 2 is a schematic view showing another embodiment of the present invention. In the first embodiment, electric power is supplied to the heating part and the ionizing part of the filament 14 from one AC power source 41. , Filament 34
An intermediate terminal is provided to supply electric power to the heating portion and the ionizing portion from the AC power sources 42 and 43, respectively. This makes it possible to control the amounts of clusters 3a and atoms 3b generated,
Since the production amounts of the cluster ions 3c and the atomic ions 3d can be controlled, a thin film of good quality can be formed under the optimum conditions.

[0013]

As described above, according to the present invention,
A filament arranged surrounding the crucible is composed of a heating part that emits thermoelectrons that collide with the crucible and an ionizing part that emits thermoelectrons that strike the atoms and clusters ejected from the nozzle and the cluster, and Since power is supplied from one AC power source, the structure is simple and the cost can be reduced, and there is an effect that droplets of the deposition material are not generated.

Further, since electric power is supplied to each of the heating portion and the ionizing portion of the filament from one AC power source, it is possible to control the generation amounts of clusters and atoms and the generation amounts of cluster ions and atomic ions. This has the effect of forming a thin film of good quality by vapor deposition under optimal conditions.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of the present invention.

FIG. 2 is a schematic view showing another embodiment of the present invention.

FIG. 3 is a schematic view showing a conventional thin film forming apparatus.

[Explanation of symbols]

 1 vacuum tank 2 crucible 2a nozzle 3 deposition material 3a cluster 3b atom 3c cluster ion 3d atomic ion 10 vacuum evacuation system 11 substrate 14 filament 19a acceleration electrode 19b acceleration electrode 22 first DC power supply 25 third DC power supply 34 filament 41 AC Power supply 42 AC power supply 43 AC power supply

Claims (2)

[Claims] 1. A substrate and a crucible filled with a vapor deposition substance are placed inside a vacuum chamber maintained at a predetermined degree of vacuum, and the crucible is heated by collision of thermoelectrons to vaporize the vapor deposition substance in the crucible. Neutral that does not ionize by accelerating ionized atomic ions and cluster ions ejected from a nozzle and applying thermal electrons to the atoms of the vapor deposition material and the clusters of the above-mentioned atoms that have agglomerated in a supercooled state due to adiabatic expansion, due to the electric field In a thin film forming apparatus for forming a thin film of the vapor deposition material by bombarding the surface of the substrate with the atoms and the clusters of
The filament arranged surrounding the crucible is composed of a heating portion that emits thermoelectrons that collide with the crucible, and an ionization portion that emits thermoelectrons that are applied to the atoms and the clusters ejected from the nozzle. And a thin film forming apparatus characterized in that electric power is supplied to the filament from one AC power source. 2. The thin film forming apparatus according to claim 1, wherein electric power is supplied to each of the heating portion and the ionizing portion of the filament from one AC power source.