JPS6272111A - Thin film forming device - Google Patents

Abstract

PURPOSE:To improve the rate of ionization for a cluster as well as to form a thin film of excellent characteristics by a method wherein the potential of a thermal shielding plate is biased negatively for an ionized filament. CONSTITUTION:A cluster 4 is formed by adiabatic expansion generated when it is jetted out from a nozzle. Also, the fourth DC power source to be used for biasing is provided, and as a result, a thermal shielding plate 19 is brought in the state of negative potential for an ionized filament 8. Consequently, the potential distribution formed by the action of the bias voltage applied by the DC power source is 20 formed. As a result, most of the thermion (e<->) discharged from the filament 8, ionized by heating by the application of power from an AC power source 10, is brought out to the internal part of the grid, and the cluster 4 is ionized at a high probability. Consequently, the rate of ionization for the cluster can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thin film forming apparatus that forms a film using ions.

[Conventional technology]

FIG. 2 is a sectional view of a conventional ICB (ion cluster beam) type thin film forming apparatus disclosed in, for example, Japanese Patent Laid-Open No. 54-9592. In the figure, (1) is a crucible, (2
) What is melted in the tobacco crucible (1) ff, (
3) is at least one nozzle drilled in the upper part of the crucible (I+), and the melted substance (
2) is evaporated and its vapor (4) is spewed out. (5) is the bombarded filament I-, +6 that heats the crucible (1)
1 is an AC power source that energizes the bombarded filament (5), (7) is a first DC power source for bias, and (8) is an ionization filament, which uses the ionization electrons emitted from it as part of the vapor (4). The particles collide with each other to form positively charged cluster ions. (9) is the ionized filament l-
A grid that accelerates the ionizing electrons emitted from +81 and causes them to collide with the steam (4) ejected from the crucible (1); (10) is an AC power source that generates heat for the ionizing filament (8); 11) is a second DC power source for bias, (12) and (13) are grid 1 electrodes and acceleration electrodes that accelerate the cluster ionized vapor (4), and (14) has (15) formed on its surface. (16) 1. t Third DC power supply for bias, (
17) is a heat shield plate for the crucible (11), (18) is a vacuum chamber, and (19) is a heat shield plate for the ionized filament l-+81.
1 ability 1.1 It is as follows.

First, the first i-current power source (7) is connected to the heating filament (5).
In order for the electrons emitted from to collide with the crucible (1),
The potential of the crucible (1) is positively biased with respect to the filament (5). Next, the second DC power supply (11) biases the ionized filament l-(81) to a negative potential with respect to the grid (9).The third DC power supply (16) also biases the substrate (14), which is at ground potential, and The grid electrode 1u (12) is biased to a positive potential with respect to the accelerating electrode (13).

Incidentally, the bombarded filament (5) and the heat rolled temporary (17) are connected to the same potential, and the ionized filament (8) and its heat shield plate (19) are connected to the same potential.

Next, its operation will be explained. First, AC power supply (6)
The bombarded filament (5) is heated to emit thermionic electrons, but in this case, a positive bias voltage is applied to the crucible (1) by the first DC power supply (7). )
Therefore, the thermoelectrons are impinged on the crucible (1) and the crucible (1) is heated. And this heated tnia 1
...The substance 'l'l [2] in 1ll will evaporate and steam (4) will be ejected from its nozzle (3) into the vacuum area. Next, the ejected steam (4) becomes a supercooled state due to adiabatic expansion due to the pressure difference between the nozzle (1) and the vacuum chamber (18), and about 100 to 200 atoms combine to form a cluster. (forms a lumpy atomic group). This cluster shoots out from the ionized filament (8) and
It collides with the electrons extracted by Sodo (9), and as a result, the electrons of the substance are knocked out and become positively charged Clasque ions. The cluster ions are accelerated by an accelerating electrode (13) and reach the substrate (14) to form a film (15).

[Problem that the invention seeks to solve]

The conventional thin film forming apparatus is constructed as described above, and since the ionized filament l-[81 is at the same potential as the heat shield plate (19) for this ionized filament, a potential gradient exists between them. do not. Therefore, only the electrons ejected from the ionization filament (8) toward the grid (9) contribute to the ionization of the vapor (4), and the ionization rate becomes small. However, there was a problem in that the performance of the thin film was significantly reduced.

[Means for solving problems]

This invention was made in order to solve the above-mentioned problem 5, and the potential of the irises shield plate is negatively biased with respect to the ionized filament 1.

1 Effect] According to the present invention, electrons ejected from the ionized filament (8) are It is then drawn out to the center of the vacuum chamber and exposed to steam, which improves the ionization rate.

[Embodiments of the invention]

Hereinafter, thin film formation according to one embodiment of the present invention will be explained using the cross-sectional view of the main parts shown in FIG. , I will explain only the colored parts between this and the (different -). In Figure 1, (20) is the fourth current correction power source for bias, and this is the ionizing filament (8). The heat shield plate (19) is kept at a negative potential.As a result, a broken-line potential distribution is generated in cooperation with the second bias power source (11), which causes the ionized filament l-(81 to jump out). Steam (4) passes through all of these thermionic electrons e.
The vapor (or cluster) is drawn out to the center of the vacuum chamber (18) where it undergoes ionization.

In addition, - although the above explanation was about an IcB thin film forming apparatus, the present invention is not limited thereto, and can be applied to an example or a sputtering nog apparatus, an ion-containing Q-necking apparatus, or an ion blating apparatus. Therefore, the same effect as the above embodiment is achieved. Furthermore, although bonobird filament l-f51 is shown as a means for heating the crucible (1), resistance heating may be used as a means for heating the crucible (1).

〔Effect of the invention〕

As detailed above, according to the present invention, the ionization rate is increased by negatively biasing the i-position of the heat shield plate with respect to the ionization filament, so that the ionization rate is increased to a certain upper limit determined by the space charge effect. The result is that the ionic current density can be created over a large area, and a thin film with high performance and homogeneity can be formed over a wide area.

[Brief explanation of drawings]

FIG. 1 is a sectional view of essential parts of a thin film forming apparatus according to an embodiment of the present invention, and FIG. 2 is a sectional view (C) of a conventional thin film forming apparatus. In the figure, (1) is a crucible, (2) is a film-forming substance, and (
3) is the nozzle, +41 is the steam, (5) is the bombarded filament, (8) is the ionization filament, (9) is the grid, (12) is the grid electrode, (13) is the acceleration electrode, (14) is the substrate, ( 15) is a membrane, (17) and (1
9) is a heat shield plate, and (18) is a vacuum chamber. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent Patent Attorney Masaru Sato Procedural Amendment (,e)

Claims (1)

[Scope of Claims] A thin film forming apparatus that forms a film on a predetermined substrate by ionizing a film-forming substance using electrons emitted from an ionized filament that is heat-shielded by a heat-shield plate, comprising: A thin film forming apparatus comprising a bias means for biasing the ionization filament to a negative potential.