JPH0641731A - Vacuum vapor deposition device - Google Patents

Abstract

PURPOSE:To prevent the surface of a semiconductor substrate from charging with plus or minus charges without depending on the vaporization conditions or the kind of vapor deposition material or partial ionization of the vapor deposition material. CONSTITUTION:In a vacuum chamber 11, the vapor deposition source 13 is heated and molten by irradiation of electron beams so that the vapor deposition material vaporized from the vapor source 13 is deposited on the surface of a material 14 to be coated which is disposed facing to the vapor source. In this device, an electromagnet 18 is disposed between the vapor source 13 and the material 14 to be coated so that the course of secondary electrons which are emitted from the vapor source 13 to the material 14 is deviated by the electromagnet 18. The intensity of the magnetic field (b) of the electromagnet 18 is varied by controlling the current in the electromagnet 18. Further, this device is equipped with an electrode plate 19 to measure the charge-up amt. which is rendered in the same state as the material 14 to be coated, a monitor 20 to monitor the charge-up amt., and a magnetic force controller 21 to control the intensity of the magnetic field (b) of the electromagnet 18 according to the detection output of the monitor 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum vapor deposition apparatus, and more particularly, it is used for manufacturing semiconductor devices and the like, and a vapor deposition material is deposited on the surface of a semiconductor substrate in a vacuum chamber to form electrodes and insulating films. The present invention relates to a vacuum vapor deposition device for forming.

[0002]

2. Description of the Related Art For example, in manufacturing a semiconductor device such as an FET, a vacuum evaporation apparatus is used as a production facility for forming a gate electrode. An electron beam vapor deposition apparatus, which is a type of vacuum vapor deposition apparatus, will be described below with reference to FIG.

In this electron beam vapor deposition apparatus, a filament (2) for emitting thermoelectrons is arranged at the bottom of a vacuum chamber (1) as shown in the figure, and the filament (2) is heated to emit thermoelectrons. Filament circuit (3)
Are connected outside the chamber. Further, a vapor deposition source (4) in which a vapor deposition material such as Al is housed in a crucible or the like is arranged near the filament (2), and a semiconductor substrate is provided above the vacuum chamber (1) with respect to the vapor deposition source (4). (5) The [semiconductor wafer] is arranged to face each other with its processing surface facing downward by an appropriate supporting means (6) such as a holder.

A first magnetic field (a) for bending the thermoelectrons emitted from the filament (2) toward the vapor deposition source (4) between the filament (2) and the vapor deposition source (4).
A permanent magnet (7) for generating is arranged. The permanent magnet has a position-adjustable structure in order to adjust the strength of the magnetic field so that the thermoelectrons from the filament (2) properly reach the vapor deposition source (4).

Further, the vapor deposition source (4) and the semiconductor substrate (5)
And a second magnetic field (b) for bending secondary electrons, which are generated from the vapor deposition source (4) and are directed toward the semiconductor substrate (5), in a direction other than the semiconductor substrate (5) for the reason described later. The permanent magnet (8) for generating is fixedly arranged.

In the above vacuum vapor deposition apparatus, the thermoelectrons emitted by heating the filament (2) emit a first magnetic field (a).
To enter the vapor deposition source (4). Due to the incident energy of these thermoelectrons, the vapor deposition material of the vapor deposition source (4) is heated and melted,
The vapor deposition material evaporated from the vapor deposition source (4) adheres to the processed surface of the semiconductor substrate (5) to form a gate electrode. At this time, thermoelectrons are incident on the vapor deposition source (4) with a predetermined energy, so that the vapor deposition material is evaporated and secondary electrons are emitted from the vapor deposition material. When the secondary electrons reach the semiconductor substrate (5), the surface of the semiconductor substrate (5) is negatively charged up, and the elements of the semiconductor substrate (5) may be destroyed by the discharge of the charged-up electrons. Therefore, as described above, the secondary electrons emitted from the vapor deposition source (4) are bent by the second magnetic field (b) so that the secondary electrons do not reach the semiconductor substrate (5).

[0007]

By the way, in the conventional apparatus, in order to prevent the secondary electrons generated from the vapor deposition source (4) from reaching the semiconductor substrate (5), the vapor deposition source (4) is moved to the semiconductor substrate (5). The secondary electrons are directed to be bent by the second magnetic field (b).

Here, the permanent magnet (8) for generating the second magnetic field (b) is fixedly arranged, and the strength of the second magnetic field (b) is constant. On the other hand, it is clear that the energy and the amount of the secondary electrons greatly change depending on the evaporation condition and type of the vapor deposition material. Therefore, as described above, when the second magnetic field (b) is always constant, the secondary electron does not bend properly and reach the semiconductor substrate (5) under certain evaporation conditions and types of evaporation material. However, when the evaporation conditions and types of the vapor deposition material change and the energy and amount of secondary electrons increase, some of the secondary electrons reach the semiconductor substrate (5) and its surface There was a problem of being charged up.

Further, a part of the vapor deposition material evaporated from the vapor deposition source (4) contains positively ionized ones due to the impact when secondary electrons are incident on the vapor deposition source (4).
Since the secondary electron has a small mass, it is appropriately bent by the second magnetic field (b), and even if it does not reach the semiconductor substrate (5), the positively ionized vapor deposition material has a large mass. Therefore, the semiconductor substrate (5) reaches the semiconductor substrate (5) without being bent by the second magnetic field (b) and its surface is positively charged up contrary to the case of secondary electrons. There is a problem that the element may be destroyed.

Therefore, the present invention has been proposed in view of the above problems, and an object of the present invention is not to be influenced by the evaporation conditions and types of the vapor deposition material and the ionization of a part of the vapor deposition material. It is an object of the present invention to provide a vacuum vapor deposition apparatus capable of preventing the surface of a substrate from being charged up either positively or negatively.

[0011]

As a technical means for achieving the above-mentioned object, the present invention makes an electron source incident on a vapor deposition source arranged in a vacuum chamber and heats and vaporizes the vapor deposition source by its incident energy. In the method of depositing the vapor deposition material evaporated from the vapor deposition source on the surface of the vapor deposition material that is arranged opposite to the vapor deposition source, the vapor deposition source is provided in the course of the vapor deposition material between the vapor deposition source and the vapor deposition material. It is characterized in that a magnetic field generating means for bending the path of secondary electrons generated from the magnetic field generating means to bend the path of the secondary electron is arranged, and the strength of the magnetic field of the magnetic field generating means is made variable.

According to the present invention, the above-mentioned magnetic field generating means for varying the magnetic field strength, the electrode plate for measuring the charge-up amount arranged in the same state as the object to be vapor-deposited, and the charge-up at the electrode plate are carried out. It is desirable to include a monitor for monitoring the amount and a magnetic force controller for controlling the strength of the magnetic field of the magnetic field generating means based on the charge-up amount detected by the monitor.

Further, specifically, the magnetic field generating means is preferably an electromagnet or a movable permanent magnet.

[0014]

In the vacuum vapor deposition apparatus according to the present invention, the strength of the magnetic field of the magnetic field generating means for bending the secondary electrons from the vapor deposition source toward the object to be vapor-deposited is variable, so that the secondary electrons can be changed depending on the vaporization condition and type of the vapor deposition material. The energy and quantity of
Even if a part of the vapor deposition material is ionized, depending on the evaporation conditions and type of the vapor deposition material, and the amount of the ionized vapor deposition material, the appropriate magnetic field strength is set so that the surface of the deposition target does not charge up. It becomes possible.

If an electrode plate, a monitor and a magnetic force controller are provided in addition to the magnetic field generating means for varying the magnetic field strength,
By monitoring with a monitor, operate the magnetic force controller so that the surface of the deposition object under the same conditions as the electrode plate will not be charged up, and automatically set the magnetic field strength in the magnetic field generation means to an appropriate value. You can

Further, if the magnetic field generating means is an electromagnet, the adjustment to make the strength of the magnetic field an appropriate value can be carried out depending on the amount of energization to the electromagnet, and a movable permanent magnet can be used. If so, it can be performed by changing the relative position of the permanent magnet with respect to the secondary electron passage region.

[0017]

EXAMPLE An example of a vacuum vapor deposition apparatus according to the present invention will be described with reference to FIGS.

FIG. 1 shows an electron beam evaporation apparatus which is a kind of vacuum evaporation apparatus. As shown in FIG.
A filament (12) for emitting thermoelectrons is arranged at the bottom of 1), and a vapor deposition source (13) in which a vapor deposition material such as Al is stored in a crucible or the like is fixedly arranged in the vicinity of the filament (12). On the other hand, a semiconductor substrate (14) [semiconductor wafer] is placed on the upper part of the vacuum chamber (11) so as to face it with its processing surface facing downward by an appropriate supporting means (15) such as a holder. A filament circuit (16) for emitting thermoelectrons by heating is connected to the filament (12) outside the chamber. Further, the filament (12) and the vapor deposition source (13)
And a permanent magnet (17) that generates a first magnetic field (a) for bending the thermoelectrons emitted from the filament (12) toward the vapor deposition source (13). The permanent magnet (17) has a position-adjustable structure for adjusting the strength of the magnetic field so that the thermoelectrons from the filament (12) can properly reach the vapor deposition source (13).

The above structure has the same structure as the conventional device,
The device of the present invention is characterized by the following configurations.

First, the vapor deposition source (13) and the semiconductor substrate (1
4) between the semiconductor substrate (1) generated from the vapor deposition source (13)
As a magnetic field generating means for generating a second magnetic field (b) for bending the secondary electrons toward 4) in a direction other than the semiconductor substrate (14), for example, an electromagnet (18) is arranged and the electromagnet (18) is arranged. Depending on the size of the current supplied to the coil in 18),
The strength of the magnetic field (b) is changed.

On the other hand, an electrode plate (19) for measuring the amount of charge-up is set near the semiconductor substrate (14) under the same conditions as the semiconductor substrate (14) arranged above the vacuum chamber (11). Then, on the electrode plate (19),
A monitor (20) for monitoring the charge-up amount in the electrode plate (19) is connected outside the vacuum chamber (11). Furthermore,
Based on the charge-up amount detected by the monitor (20), the monitor (20) controls the strength of the second magnetic field (b) by the electromagnet (18) so that the charge-up amount becomes zero. The magnetic force controller (21) is connected, and the electromagnet (18) is connected to the output of the magnetic force controller (21).

In the electron beam vapor deposition apparatus having the above structure, the thermoelectrons emitted by the heating of the filament (12) are made incident on the vapor deposition source (13) by the first magnetic field (a), as in the conventional case. Incident energy heats and melts the vapor deposition material of the vapor deposition source (13), and the vapor deposition material evaporated from the vapor deposition source (13) adheres to the processing surface of the semiconductor substrate (14) to form a gate electrode.

At this time, thermoelectrons are incident on the vapor deposition source (13) with a predetermined energy, and secondary electrons are emitted from the vapor deposition material as the vapor deposition material evaporates. When the secondary electrons reach the semiconductor substrate (14), the surface of the semiconductor substrate (14) is negatively charged up, and the elements of the semiconductor substrate (14) may be destroyed by the discharge of the charged up electrons. There is. Meanwhile, the evaporation source (1
A part of the vapor deposition material evaporated from 3) contains positively ionized secondary electrons due to the impact when the secondary electrons enter the vapor deposition source (13). When this positively ionized vapor deposition material reaches the semiconductor substrate (14), its surface is positively charged up contrary to the case of secondary electrons, and this charge-up also destroys the element of the semiconductor substrate (14). May occur.

Here, since the secondary electron has a small mass, the range can be bent by the second magnetic field (b) as in the conventional case, and the secondary electron is prevented from reaching the semiconductor substrate (14). However, since the positively ionized vapor deposition material has a large mass, it is difficult to bend even with the second magnetic field (b).

Therefore, in the present invention, the charge-up amount by the secondary electrons reaching the electrode plate (19) set under the same conditions as the semiconductor substrate (14) and the positively ionized vapor deposition material is monitored (20). Monitor and monitor it (2
Magnetic force controller (21) based on the signal output from (0)
Controls the energization of the electromagnet (18).

More specifically, if more secondary electrons reach the semiconductor substrate (14), that is, the electrode plate (19) than the positively ionized vapor deposition material, the surface thereof becomes negatively charged. When it is up, from the monitor (20),
An output signal for increasing the strength of the second magnetic field (b) by the electromagnet (18) is transmitted, and the output signal outputs a signal for increasing the amount of electricity supplied from the magnetic force controller (21) to the electromagnet (18). The strength of the second magnetic field (b) generated by the electromagnet (18) is increased due to the increase in the amount of electricity supplied to the electromagnet (18). This further bends the passing secondary electrons, making it difficult for the secondary electrons to reach the semiconductor substrate (14) and the electrode plate (19), reducing the amount of negative charge-up, and reducing the entire surface of the electrode plate (19). The positive charge-up amount due to the positively ionized vapor deposition material and the negative charge-up amount due to the secondary electrons are offset.

On the contrary, when the positively ionized vapor deposition material reaches the electrode plate (19) more than the secondary electrons and the surface thereof is positively charged up, the monitor (2
From 0), an output signal that reduces the strength of the magnetic field generated by the electromagnet (18) is sent, and the output signal outputs a signal that reduces the amount of electricity supplied to the electromagnet (18) from the magnetic force controller (21). As a result, the strength of the second magnetic field (b) generated by the electromagnet (18) is reduced due to the decrease in the amount of electricity supplied to the electromagnet (18). This makes it difficult for the secondary electrons passing therethrough to bend, and makes it easier to reach the semiconductor substrate (14) and the electrode plate (19), increasing the amount of charge-up to a negative value, and increasing the entire surface of the electrode plate (19). The negative and positive charge-up amounts of are offset.

As described above, the electromagnet (18) is passed through the monitor (20) and the magnetic force controller (21) according to the relative plus and minus charge-up amounts on the surface of the electrode plate (19). ) By adjusting the strength of the second magnetic field (b) as described above, the offset of the positive and negative charge-up amounts on the surface of the electrode plate (18) cancels the electrode plate (1).
8) That is, the surface of the semiconductor substrate (14) is prevented from being positively or negatively charged up by the positively ionized vapor deposition material and secondary electrons.

Even if the evaporation condition and type of the evaporation material in the evaporation source (13) are changed and the energy and the amount of the secondary electrons are changed, the adjustment by the electromagnet (18) is performed by the above-mentioned adjustment. By varying the strength of the second magnetic field (b), the surface of the semiconductor substrate (14) is always charged to positive or negative without being affected by the energy and amount of secondary electrons. You can prevent it from going up.

Although the electromagnet (18) has been described as the magnetic field generating means in the above embodiment, the present invention is not limited to this, and the movable permanent magnet (22) as shown in FIG. 2 is used. Can also be used, magnetic force controller (21)
The drive mechanism (23) is operated based on the output signal from the drive mechanism (23), and the drive mechanism (23) moves the permanent magnet (22) by a predetermined amount, whereby the second magnetic field (b) generated by the permanent magnet (22). ) To change the strength.

[0031]

According to the present invention, the strength of the magnetic field of the magnetic field generating means for bending the secondary electrons from the vapor deposition source toward the object to be vapor-deposited is made variable, so that the secondary electron emission depends on the vaporization condition and type of the vapor deposition material. Even if the energy and its amount change, or even if a part of the evaporation material is ionized, the surface of the object to be evaporated does not charge up depending on the evaporation condition and type of the evaporation material and the amount of the ionized evaporation material. Such an appropriate magnetic field strength can be set, the yield of products is significantly improved, and the work of adjustment work such as condition setting can be saved and workability is dramatically improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a vacuum vapor deposition device according to the present invention.

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

FIG. 3 is a schematic configuration diagram showing a conventional example of a vacuum vapor deposition device.

[Explanation of symbols]

 11 Vacuum chamber 13 Deposition source 14 Deposition object (semiconductor substrate) 18 Magnetic field generating means (electromagnet) 19 Electrode plate 20 Monitor 21 Magnetic force controller b Magnetic field

Claims (4)

[Claims] 1. An object to be vapor-deposited in which an electron beam is incident on a vapor deposition source arranged in a vacuum chamber, the vapor deposition source is heated and melted by the incident energy, and the vapor deposition material vaporized from the vapor deposition source is arranged to face the vapor deposition source. A magnetic field generating means for bending the course of secondary electrons generated from the vapor deposition source and directed toward the vapor deposition material in the course of the vapor deposition material between the vapor deposition source and the vapor deposition material. A vacuum vapor deposition apparatus characterized in that the magnetic field intensity of the magnetic field generating means is variable. 2. A magnetic field generating means having variable magnetic field strength according to claim 1, an electrode plate for measuring a charge-up amount arranged in the same state as the deposition object, and a charge-up amount at the electrode plate. And a magnetic force controller that controls the strength of the magnetic field of the magnetic field generating means based on the charge-up amount detected by the monitor. 3. The magnetic field generating means according to claim 1 or 2,
A vacuum deposition apparatus characterized by being an electromagnet. 4. The magnetic field generating means according to claim 1 or 2,
A vacuum evaporation apparatus, which is a movable permanent magnet.