JPH0649934B2 - Method for controlling automatic operation sequence of thin film forming apparatus - Google Patents

Description

The present invention relates to an automatic operation sequence control method for a thin film forming apparatus, particularly an ICB vapor deposition apparatus.

[Conventional technology]

FIG. 6 shows a thin film forming apparatus such as Japanese Patent Publication No. 54-959.
It is a schematic block diagram of the ICB (cluster ion beam) vapor deposition apparatus disclosed by the 2nd publication. And Fig. 4 is like this
FIG. 5 is a sequence diagram for explaining the conventional automatic operation sequence control method for controlling the ICB vapor deposition apparatus, and FIG. 5 is a flow chart for explaining the sequence diagram of FIG. In the figure, (31) is the crucible and (32) is the crucible.
Evaporated substance melted in (31), (33) is crucible (31)
At least one nozzle opened in the upper part of the nozzle, (34) is a cluster formed by vaporizing the molten vapor deposition material (32) and ejecting the vapor from the nozzle (33), and (35) is a crucible. A bombard filament that heats (31), (36) a first AC power source that electrically heats this bombard filament (35), (37) a first DC power source for bias, and (38) emits an ionizing electron. In the ionization filament, the ionizing electrons collide with a part of the cluster (34) to form positively charged cluster ions. (39) is a grid that accelerates the ionizing electrons emitted from the ionization filament (38) and collides them with the cluster (34) ejected from the crucible (31), and (40) energizes the ionization filament (38). A second AC power source for heating, (41) a second DC power source for bias, (42) and (43), respectively, a grid electrode and an acceleration electrode for accelerating and controlling cluster ions formed by ionizing the cluster (34), Reference numeral (44) is a substrate on which a thin film (45) is formed. (46) is a third DC power supply for bias, (47) is a first heat shield plate for heat-shielding the crucible (31),
(48) is a vacuum tank, (49) is a second heat shield plate for heat shielding the ionization filament (38), (50) is a first DC power supply (37), a second DC power supply (41), a third DC power supply (46) and first
An AC power supply (36) and a power supply device accommodating the second AC power supply (40), (51) an ionization vacuum gauge for measuring the degree of vacuum in the vacuum chamber (48), and (52) a deposited thin film ( A film thickness sensor for measuring the thickness of (45), (53) is a shutter that blocks deposition material (2) from being deposited on the substrate (44), (54) is a power supply unit (50), shutter
A control device that controls (53) and monitors the ionization vacuum gauge (51) and the film thickness sensor (52), and (55) is a vacuum exhaust device.

First, the function of each bias power supply in the power supply device (50) will be described. The first DC power supply (37) positively sets the potential of the crucible (31) with respect to the bombard filament (35) so that the thermoelectrons emitted from the bombard filament (35) for heating the crucible collide with the crucible (31). To bias. Second DC power supply
(41) is an ionization filament (38) against a grid (39)
Is biased to a negative potential, and the thermoelectrons emitted from the ionization filament (38) are extracted inside the grid (39). Further, the third DC power supply (46) biases the grid electrode (42) to a positive potential with respect to the acceleration electrode (43) which is at the ground potential, and is generated inside the grid by the electric field lens formed between both electrodes. Acceleration control of positively charged cluster ions.

The conventional automatic operation sequence control method is applied to the ICB vapor deposition device configured as described above. Step (1) in Fig. 5
Then, the exhaust system of the ICB vapor deposition device is started, that is, the vacuum chamber (48) is exhausted by the vacuum exhaust device (55). In step (2), the degree of vacuum in the vacuum chamber (48) is measured by the ionization vacuum gauge (51). In step (3), it is determined whether the vacuum degree in step (2) is less than or equal to the set vacuum degree, for example, about 1.0 × 10 ⁻⁶ Torr. If not, continue exhausting further,
If so, move to step (4) and control (54)
To the bombard filament (35) and the ionization filament (38) by energizing and heating them, respectively.
6) and a signal for driving the second AC power source (40) are transmitted, and these AC power sources electrically heat each filament at a startup rate of about several amperes [A] per minute. In steps (5) to (7), these filaments are gradually heated until the temperature and current of these filaments reach set values, for example, about 2000 ° C. and 25 to 30 amperes (A), respectively (in this state, A current for supplying the bombardment filament energizing current A and the ionization filament energizing current A shown in FIGS. 4B and 4C is supplied. When the electric heating process of the bombard filament (35) and the ionization filament (38) is completed, in the steps (8) to (11), the controller (54) supplies the first DC power source (37) and the second DC power source (41). A signal is sent to drive the. As a result, the bombardment voltage is applied between the crucible (31) and the bombardment filament (35) from the first DC power supply (37), and the bombardment current flowing between them is increased by about 0.5 amperes per minute [A]. The bombardment voltage is controlled until a predetermined bombardment input (the product of the bombardment current and the bombardment voltage) is obtained (shown by (B) in FIGS. 4 (d) and 4 (e)). At the same time, an ionization voltage is applied from the second DC power supply (41) between the grid (39) and the ionization filament (38), and the ionization current that is a standard for ionizing the cluster (34) is 0.5 amperes per minute. [A] The ionization voltage is controlled until it is increased by about a certain amount and reaches a predetermined value [fourth
(C) of Figures (f) and (g)].

Next, when the start-up of the ionization section and the bombard section is completed, the third DC power supply (46) is turned on by a command from the control device (54) in step (12), and a predetermined acceleration voltage is applied to the acceleration electrode (43). Applied between the electrode and the grid electrode (42) [5th
Figure (a) (D)]. In this way, the pretreatment before vapor deposition proceeds, and as the final startup, in steps (13) and (14), the degree of vacuum in the vacuum chamber (48) measured by the ionization vacuum gauge (51). Is evacuated to, for example, 3.0 × 10 ^-6 Torr or less (this is a vacuum degree at which the performance of the thin film (45) formed on the surface of the substrate (44) is guaranteed). After reaching the predetermined value, in step (15), a signal for opening the shutter (53) is transmitted from the control device (54) [see FIG. 4 (h)].
(E)], evaporation is started on the surface of the substrate (44) to form a thin film (45)
Is formed. In steps (16) and (17), the thin film (4
The film thickness of 5) is measured by the film thickness sensor (52), and a predetermined film thickness is formed [(E) to (F) of FIG. 4 (i)], and at step (18), The control device (54) issues a command to close the shutter (53) [(F) in FIG. 4 (h)], and the deposition of the thin film (45) is completed. From the next step, post-processing of vapor deposition is performed,
First, in step (19), signals for turning off the acceleration voltage, the bombard voltage, and the ionization voltage from the control device (54) are the third DC power supply (46), the first DC power supply (37), and the second DC power supply, respectively. Transmitted to (41) [Fig. 4 (a), (d) to (f)]
(G)]. Next, in step (20), signals for turning off the energizing currents of the bombard filament (35) and the ionization filament (38) are transmitted to the first AC power source (36) and the second AC power source (40), respectively (Fig. 4). (B) and (c)], the shutdown is completed. Then, at step (21), the vacuum exhaust device is
After the ICB vapor deposition apparatus is cooled while (55) is operated, the exhaust system is turned off at step (22) and the substrate (44) is taken out.

[Problems to be solved by the invention]

In the conventional automatic operation sequence control method of the ICB vapor deposition device, the degassing amount to be exhausted varies depending on the past operation history, regardless of the degree of vacuum, energization heating of each filament followed by the bombard current, Since the ionization current is started up, when there is a large amount of degassing as described above, there is a problem that it takes time to evacuate after completion of start-up until the shutter is opened. There is a problem that the life of the equipment is shortened because the vapor deposition material is accumulated in the ejected equipment and the vapor deposition material is wasted, and when the operation is stopped for a long time or the vacuum chamber is opened to the atmosphere. Since the filament surface is partially covered with an oxide film and the number of thermoelectrons emitted from the heated filament is reduced compared to the case of continuous operation, the filament heating current is That the start-up voltage - current characteristic becomes unstable, a problem that can be automatically controlled difficult has been made as compared with the characteristics in the case of continuous operation.

The present invention has been made to solve such problems, and an object thereof is to obtain an automatic operation sequence control method for an ICB vapor deposition device, which can stably form a high quality thin film and promises a long life. To do.

[Means for solving problems]

The automatic operation sequence control method for a thin film forming apparatus according to the present invention is arranged so that the degree of vacuum in the vacuum chamber can be monitored, and after confirming that the degree of vacuum described above has been exhausted until it becomes equal to or lower than the first set degree of vacuum. , The bombard filament and the ionization filament are preheated to a desired set current value, and further, the vacuum degree is evacuated to the second set vacuum degree and the heating of each filament is stopped, and the vacuum degree is set to the third vacuum degree. After being evacuated to a level not higher than the set vacuum degree, the accelerating voltage is applied to the cluster ions generated in the vacuum chamber.

[Action]

In the present invention, while monitoring the degree of vacuum, the bombard filament and the ionization filament are preheated before the vapor deposition sequence, the oxide film on the surface of each filament is removed, and the startup of each filament is stably reproduced.

〔Example〕

FIG. 1 is a sequence diagram for explaining an automatic operation sequence control method for a thin film forming apparatus of the present invention, and FIG. 2 is a first diagram.
Flow chart diagram for explaining the sequence diagram of the figure,
FIG. 3 is a schematic configuration diagram of an ICB vapor deposition apparatus in which the present invention is implemented. In the figure, (31) to (53) and (55) are the same as those shown in FIG. 6, and (54A) Is the controller used in the present invention.

The automatic driving sequence control method of the present invention is carried out as follows.

First, the exhaust system is operated at step (100) in FIG.
The inside of the vacuum chamber (48) is exhausted by the vacuum exhaust device (55).
After confirming that the degree of vacuum has reached the first set degree of vacuum, for example, 1.0 × 10 ⁻⁵ Torr or less, at steps (101) and (102), the process proceeds to step (103). In steps (103) to (105), the control device (54A) turns on the first AC power supply (36) and the second AC power supply (40).
A signal to send N is sent, Bombard filament
(35) and the ionization filament (38) are 5 amperes [A] per minute until the amperage reaches 30 amps [A].
The temperature is raised by one step and preheated [the period from the start of FIG. 1 (b) and (c) to (K)]. At this time, the controller (54A) constantly monitors the degree of vacuum in the vacuum chamber (48) measured by the ionization vacuum gauge (51), and the amount of degassing is large and the degree of vacuum becomes 1.0 × 10 ^-5 Torr or more. In this case, the degassing is exhausted without sending a signal to increase the energization current of the filament, and the degree of vacuum is 1.0 × 10
-Wait until below ⁵ Torr. When each filament current reaches about 30 amperes [A], step (1
Proceed to 06) and it takes about 30 minutes until the oxide on the filament surface is removed or the amount of degassing decreases and the degree of vacuum reaches the second level.
Baking is carried out until the set vacuum degree, ie, about 3.0 × 10 ^-6 Torr or less [(L) in FIGS. 1 (b) and (c)]. next,
In the step (107), the first command is issued by the controller (54A).
The alternating current power supply (36) and the second alternating current power supply (40) are turned off and the current heating the bombardment filament (35) and the ionization filament (38) is reduced to zero. Then, the vacuum degree in the vacuum chamber (48) is adjusted to the third set vacuum degree by the vacuum exhaust device (55) from step (108) to (109), namely 1.0 × 10 ^-6 Torr.
It is continuously exhausted until it falls below about r. Step (110)
Then, in response to a command from the control unit (54A), the third DC power supply
(46) is turned on, and a predetermined acceleration voltage is applied between the acceleration electrode (43) and the grid electrode (42) [(D) of FIG. 1 (a)], and steps (111) to (115) In the above, in the startup process of each filament, the first AC power source (36) and the second AC power source (36) for the main heating of the bombard filament (35) and the ionization filament (38) according to a command from the controller (54A). The power supply (40) is turned on, and the energizing currents thereof are gradually increased at a rate of about 2 amperes [A] / minute. Step (116)
At (120), the first DC power supply (37) and the second DC power supply (41) are turned on by the command from the control device (54A), and the performance of the thin film (45) is guaranteed for the control device (54A). While maintaining that the vacuum chamber (48) is maintained below a predetermined vacuum degree, raise the bombarding current and the ionization current to the predetermined values [(B) in Figures 1 (e) and (g)]. And (C)]. Step (12
In 1), when the startup of each filament is completed as described above, the shutter (53) is instructed by the command from the control device (54A).
Is opened and vapor deposition is started [Fig. 1 (h) and (i)
(E)]. In steps (122) to (124), when the film thickness sensor (52) measures that the film thickness of the thin film (45) deposited on the substrate (44) reaches a predetermined value, the shutter ( 53) is closed, and vapor deposition is completed [(F) in FIGS. I (h) and (i)]. When the vapor deposition is completed in this way, at steps (125) to (127), the ionization voltage [Fig. 1 (f)], the ionization current [Fig. 1 (g)],
Bombard voltage [Fig. 1 (d)], bombard current [first
(E)], Bombard filament current [Fig. 1 (b)],
The ionization filament current [Fig. 1 (c)] is turned off, but unlike the conventional example, it is turned off gently except for the acceleration voltage [Fig. 1 (b) to (g) (G1)). , (H1)]. next,
The acceleration voltage [Fig. 1 (a)] is turned off. Since the step (128) and the subsequent steps are the same as those in the conventional example, the description is omitted.

Although the automatic operation sequence control method executed by the ICB vapor deposition apparatus has been described in the above embodiment, this automatic operation sequence control method can also be applied to a vacuum vapor deposition apparatus or an ion plating apparatus that heats a crucible by a bombard method.

〔The invention's effect〕

As described above, according to the present invention, before starting each filament current, each filament is preheated and baked, so that the degassing amount during the vapor deposition operation is small and the startup can be performed smoothly. The effect is that the stable thermoelectron emission characteristics can be obtained by starting the filament after removing the oxide on each filament surface, so that automatic control that can obtain reproducible voltage-current characteristics can be performed. As the effect, and each filament current start-up is performed while monitoring the degree of vacuum, vapor is ejected below the degree of vacuum that guarantees the performance of the thin film, the amount of waste material is small, and the shutter is opened. In addition to having a short waiting time associated with exhaust of the above, a highly accurate thin film can be formed with good reproducibility, and the life of the device can be extended.

[Brief description of drawings]

FIG. 1 is a sequence diagram of an embodiment of the present invention, FIG. 2 is a flow chart diagram for explaining the sequence diagram of FIG. 1, and FIG. 3 is a schematic configuration diagram of an ICB vapor deposition apparatus in which the present invention is implemented. FIG. 4 is a sequence diagram for explaining a conventional automatic driving sequence control method, FIG. 5 is a flow chart for explaining the sequence diagram of FIG. 4, and FIG. 6 is a conventional automatic driving sequence control method. IC controlled by
It is a schematic block diagram of a B vapor deposition apparatus. In the figure, (31) is a crucible, (32) is a vapor deposition substance, (33) is a nozzle, (34) is a cluster, (35) is a bombard filament, (36) is a first AC power supply, and (37) is a first DC power supply, (38) ionization filament, (39) grid, (40) second AC power supply, (41) second DC power supply, (42) grid electrode, (4)
3) is an accelerating electrode, (44) is a substrate, (45) is a thin film, (46) is a third DC power supply, (47) is a first heat shield plate, (48) is a vacuum chamber, (49).
Is a second heat shield plate, (50) is a power supply device, (51) is an ionization vacuum gauge, (52) is a film thickness sensor, (53) is a shutter, (54A) is a control device, and (55) is a vacuum exhaust device. Is. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A vacuum degree in a vacuum chamber can be monitored, and after confirming that the vacuum degree has been exhausted to a first set vacuum degree or less, a bombard filament and an ionization filament are set to desired values. Preheated to a current value, further evacuated until the degree of vacuum reaches a second set degree of vacuum, and stopped heating of each filament, and evacuated until the degree of vacuum becomes equal to or lower than the third set degree of vacuum. Then, an acceleration voltage is applied to the cluster ions generated in the vacuum chamber to accelerate the cluster ions, and main heating of each filament is performed while monitoring that the degree of vacuum is maintained at the second set degree of vacuum or less. Then, an automatic operation sequence control method for a thin film forming apparatus, characterized by forming a thin film.