JPS62291114A - Icb depositing apparatus - Google Patents

Abstract

PURPOSE:To use an ICB depositing apparatus for a long life by applying an accelerating voltage before energizing a filament and to control the rising time of the filament while monitoring the vacuum degree to stably form a thin film of high quality. CONSTITUTION:A predetermined accelerating voltage is applied between an accelerating electrode 13 and a grid electrode 12, the currents of a bombarding filament 5 and an ionizing filament 8 are gradually raised, the vacuum degree in a vacuum tank 18 is always monitored by an ionization vacuum meter 21, and the vacuum degree waits for the gas from an ICB depositing apparatus to be exhausted without rising the currents before the performance of a thin film becomes a proved value. Then, a bombarding voltage is applied by a second DC power source 11 between a crucible 1 and the filament 5, and an ionizing voltage is applied by a second DC power source 11 between a grid 9 and the filament 8. After a thin film 15 is deposited, a bombarding current and an ionizing current are reduced at a rate of 0.1-0.5A per minute, and the current values of the filaments 5 and 8 are reduced at a rate of approx. 2A per min.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an ICB vapor deposition apparatus, and particularly relates to an improvement in the operation sequence when forming a vapor deposited thin film.

[Conventional technology]

FIG. 1 is a sectional view of a conventional ICB (cluster ion beam) type thin film forming apparatus disclosed in, for example, Japanese Patent Publication No. 54-9592. In the figure, 1 is a crucible, 2 is a vapor deposition material that is melted in this crucible 1, and 3 is at least one nozzle bored in the upper part of the crucible 1.
The molten substance 2 evaporates from the molten material 2, and its vapor is ejected, forming a cluster 4. 5 is a bombarded filament that heats the crucible 1; 6 is an AC power source that heats the bombarded filament 5; 7 is a first DC power source for bias; 8 is an ionizing filament; collide with some of the particles to form positively charged cluster ions. 9 is a grid that accelerates the ionizing electrons emitted from the ionizing filament 8 and causes them to collide with the cluster 4 ejected from the crucible 1; 10 is an AC power source that heats the ionizing filament 8; 11 is for biasing; 12 and 13 are grid electrodes and acceleration electrodes that accelerate and control the ionized cluster 4; 14 is a substrate on which a thin film 15 is formed; 16 is a third bias voltage source;
A DC power source, 17 is a heat shield plate for the crucible 1, 18 is a vacuum chamber, 19 is a heat shield plate for the ionized filament 8, 2° is the DC power source 7, 11.16, and an AC power source 6° 10 are housed. A power supply device, 21 is an ionization vacuum needle for measuring the degree of vacuum in the vacuum chamber 18, 22 is a film thickness gauge for measuring the thickness of a deposited film, 23 is a shutter for blocking the deposition of a deposition substance on the substrate 14, and 24 is the power supply. 20, a control device that controls the shutter 23 and monitors the vacuum gauge 21 and the film thickness sensor 22; 25, a vacuum evacuation device;

First, the functions of each bias power supply in the power supply device 20 are as follows. The first DC power supply 7 positively biases the potential of the crucible 1 with respect to the filament 5 so that the thermoelectrons emitted from the crucible heating filament 5 collide with the crucible 1. Next, the second DC power supply 11 biases the ionization filament 8 to a negative potential with respect to the grid 9, and draws out the thermoelectrons emitted from the ionization filament 8 into the grid 9. Further, the third DC power supply 16 biases the grid electrode 12 to a positive potential with respect to the accelerating electrode 13 which is at ground potential, and the electric field lens formed between the two electrodes collects positively charged cluster ions generated inside the grid. Control acceleration.

Next, the operation will be explained.

The inside of the vacuum chamber 18 is 1. OX
After evacuation to a degree of vacuum of approximately 10-' Torr, a signal is first transmitted from the control bag M24 to the AC power sources 6 and 10 that heat the filaments 5 and 8 by applying electricity according to the evaporation operation sequence shown in FIG. The filament is gradually heated at a startup rate of about several A per minute until the filament temperature reaches about 2000° C., that is, until the current reaches about 25 to 30 A (FIGS. 3A and B). After the start-up of the energization heating process for the filaments 5 and 8 is completed, a signal is transmitted from the control device 24 to the first DC power supply 7 and the second DC power supply 11, and the bombardment current flowing between the crucible 1 and the filament 5 is increased to 0 per minute. A bombardment voltage is applied by the first DC power supply 7 so as to increase by about .5 A, and is controlled until a predetermined bombardment input (product of bombardment current and bombardment voltage) is reached (FIG. 3C).

At the same time, an ionization voltage is applied by the second DC power supply 11 so that the ionization current flowing between the grid 9 and the filament 8, which is a measure of the rate at which clusters 4 are ionized, increases by about 0.5A per minute. The ionization current is controlled until it reaches an ionization current of (Fig. 3D). After the ionization section and the bombardment section are started up, the control device 24 transmits a signal to the third DC power supply 16, and a predetermined acceleration voltage is applied between the acceleration electrode 13 and the grid electrode 12 (Fig. 3E). . After completion of startup, ionization vacuum gauge 21
The degree of vacuum in the vacuum chamber 18 measured at
．． 0 Xl0-”T.

After the temperature decreases to below rr, the control device 24 releases the shutter 2.
3 is transmitted (FIG. 3F), vapor deposition is started and a thin film 15 is formed on the surface of the substrate 14. This thin film 1
The film thickness of No. 5 is measured by the film thickness sensor 22, and when a predetermined film thickness is formed, the shutter 23 is activated by the control device 24.
A signal to close the gate is transmitted, and the deposition of the thin film 15 is completed (third [19G)].

Control bag then? &24, acceleration voltage, bombardment voltage,
and a signal for turning off the ionization voltage is supplied to the third DC power supply 16.
, transmitted to the first DC power supply 7 and the second DC power supply 11 (
Figure 3H), then the current flowing through filaments 5 and 8 is set to O.
The FF signal is transmitted to the AC power supplies 6 and 10 (FIG. 3 I), and the shutdown is completed. Thereafter, the device is cooled while the vacuum evacuation device 25 is kept operating, and then the substrate 14 is taken out.

[Problem that the invention seeks to solve]

Since the conventional ICE vapor deposition apparatus using the vapor deposition operation sequence is configured as described above, it has the following problems.

(The amount of degassing of the 11 equipment varies depending on the past operation history, but since the filament is energized and heated, bombarded, and the ionization current is started regardless of the degree of vacuum, if the amount of degassing is large, it may be necessary to It takes time to evacuation until the shutter is opened, and the vapor deposition material is trapped in the device that has already spouted the vapor deposition material, which shortens the life of the device and wastes the vapor deposition material.

(2) After evaporation is completed, the equipment is rapidly shut down and cooled down, so the evaporation material adheres to various parts of the equipment such as shields, especially in the case of evaporation materials that corrode equipment materials. Not only will the life of the device be significantly reduced, but also various parts of the device, such as the filament, may occasionally be destroyed due to thermal deformation caused by rapid cooling.

(3) If no accelerating voltage is applied, the electrons ejected from the filament will eject toward the crucible and grid, which are at ground potential. In this case, since the substrate is also at ground potential, some thermionic electrons may cause damage to the board.

This invention was made to solve the above-mentioned problems, and provides an ICB evaporation device that operates with a evaporation operation sequence that allows stable formation of high-quality thin films and allows the device to be used for a long time. The purpose is to

[Means for solving problems]

In the vapor deposition operation sequence of the ICB vapor deposition apparatus according to the present invention, an accelerating voltage is applied before the filament is energized, and the start-up time of the filament is controlled while monitoring the degree of vacuum. By applying an accelerating voltage in advance to accelerate cluster ions with an electric field, it prevents electrons from colliding with the substrate and causing damage, and by launching the filament while monitoring the degree of vacuum, the performance of the thin film is guaranteed. Since the vapor of the evaporation material is ejected below the vacuum level, a high-quality thin film can be formed and there is less waste of the evaporation material.After the evaporation is completed, the equipment is cooled down and shut down, so that the evaporation material is not transferred to the equipment. This reduces adhesion and increases the lifespan of the device.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. IC
The B vapor deposition apparatus is the same as the conventional example shown in FIG.

In this embodiment, the vacuum exhaust device 25 reduces the pressure inside the vacuum chamber 18 to 1. After evacuation to a degree of vacuum of approximately 10-' Torr of Ox, the ICB evaporation apparatus is controlled according to the evaporation operation sequence shown in FIG.

Hereinafter, this will be explained in detail using figures. First, a signal is transmitted from the control device 24 to the third DC power supply 16, and a predetermined accelerating voltage is applied between the accelerating electrode 13 and the grid electrode 12 (Fig. 2A).7 Next, the filament starting process begins. A major feature of the present invention is the sequence in which the filament is started up while the accelerating voltage is applied.

A signal is transmitted from the control device 24 to the AC power supplies 6 and 10 that heat the bombarded filament 5 and the ionized filament 8, and the current that heats the filaments is gradually increased. At this time, the control device 24 constantly monitors the degree of vacuum in the vacuum chamber 18 as measured by the ionization vacuum gauge 21, and determines whether the degree of vacuum is a value that guarantees the performance of the thin film or less than about 173 of that value (for example, 1. 0~3.OX 1
A signal to increase the current flowing through the filament is not sent until the current reaches 0-'Torr), and the device waits until the degassing from the device is exhausted. In this way, while constantly checking that the degree of vacuum is below a predetermined value, the rate of increase in the current flowing through the filament is controlled so that the filament temperature reaches approximately 200.
Gradually heat until the temperature reaches about 0°C (Figure 2B). Next, the control device 24 controls the first DC power supply 7 and the second DC power supply 1.
A signal is transmitted to the crucible 1, a bombardment voltage is applied between the crucible 1 and the bombarded filament 5 by the first DC power supply 7, hot electrons are ejected from the filament 5 toward the crucible 1, and a bombarded current flows. grid 9 at the same time
An ionizing voltage is applied between the filament 8 and the ionizing filament 8 by the second DC power supply 11, and thermionic electrons fly out from the filament 8 toward the grid 9, causing an ionizing current to flow. Similarly to the filament energization heating process, the control device 24 constantly monitors the degree of vacuum in the vacuum chamber 18 as measured by the ionization vacuum gauge 21, and controls the startup sequence for raising the bombardment current and ionization current to predetermined values. While checking that the current is below a value that guarantees the performance of the thin film, the ramp-up speed is controlled until the current reaches the set value (FIG. 2C).

When startup is completed in this way, the degree of vacuum has already reached a predetermined value, so the control device 24 can immediately transmit a signal to open the shutter 23 and start vapor deposition (see Figure 2). D). When the film thickness measured by the film thickness sensor 22 reaches a predetermined value, the control device 24 transmits a signal to close the shutter 23, and the thin film 15
evaporation is completed (Fig. 2E).

Next, the process moves on to shutting down the device.

First, a signal is transmitted from the control device 21 to the first DC power supply 7 and the third DC power supply 11, and the bombardment voltage and ionization are controlled so that the bombardment current and ionization current decrease at a rate of about 0.1 to 0.5A per minute. The voltage is lowered and turned off (FIG. 2 F), and then a signal is transmitted to the alternating currents 6 and 10 to increase the current value heating the bombarded filament 5 and ionized filament 8 at a rate of about 2 A per minute. Reduce it by a certain percentage and turn it off (Fig. 2 G). After the shutdown sequence is completed in this way, a signal is transmitted from the control device 24 to the third DC power supply 16, and the acceleration voltage is turned off.
F (Fig. 2H). Then a vacuum bag! After cooling the device while operating the substrate 25, the substrate 14 is taken out.

In the above embodiments, the acceleration voltage, bombardment voltage, and ionization voltage are constant after being set, but their values may be changed depending on the film forming conditions.

〔Effect of the invention〕

As described above, according to the present invention, since the accelerating voltage is applied before thermoelectrons are emitted from the fisciment, the filament potential is kept higher than the potential of the substrate (earth potential). The substrate and the thin film on the substrate are not damaged by thermionic electrons, and the filament is launched while monitoring the vacuum level, so steam is ejected at a vacuum level below which the performance of the thin film is guaranteed. Therefore, there is less wastage of the vapor deposited material, and there is less waiting time for exhaust until the shutter is opened, which not only allows formation of highly accurate thin films but also extends the lifespan of the device. In addition, since the filament is lowered over time and the device is cooled down gradually, the amount of deposited material that adheres to various parts of the device, such as shields, is reduced, and the life of the device is extended. It has the effect of

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional side view showing an ICB vapor deposition apparatus according to the present invention and a conventional one, FIG. 2 is a view showing a vapor deposition operation sequence of the ICB vapor deposition apparatus according to the present invention, and FIG. 3 is a view showing a conventional vapor deposition operation sequence. . In Figure 1, 1 is a crucible;
5 is a bombarded filament, 8 is an ionization filament, 9 is a grid, 12 is a grid electrode, 13 is an accelerating electrode, 14 is a substrate, 18 is a vacuum chamber, 20 is a DC power source 7.1
1.16 and an AC power supply 6.10;
1 is an ionization vacuum gauge, 22 is a film thickness sensor, 23 is a shutter, 24 is a control device for the entire ICB deposition apparatus, and 25 is an exhaust device.

Claims (1)

[Claims] (1) In an ICB deposition apparatus equipped with an automatic control operation function, a monitoring means for monitoring the degree of vacuum in the vacuum chamber, an acceleration voltage application means for applying an acceleration voltage for accelerating cluster ions with an electric field, and the above-mentioned acceleration in advance Apply an accelerating voltage by the voltage application means, obtain the output of the monitoring means, heat the bombarded filament and the ionized filament and apply voltage at a vacuum level below which guarantees the performance of the thin film, and stop applying the voltage to the filament. and a vapor deposition operation sequence control means for gradually performing cooling so as to reduce adhesion of the vapor deposition substance to the apparatus.
CB vapor deposition equipment.