JPS595732Y2 - Ion plating equipment - Google Patents

Description

[Detailed explanation of the idea] This invention relates to an ion plating device.

Conventionally, ionization devices used in high-vacuum arc discharge type ion plating equipment evaporate the evaporation material in the evaporation source, generate an arc discharge between the evaporation source and an ionization electrode installed near the evaporation source, and remove evaporated particles. It was intended to ionize.

In such devices, if a conductor or a similar semiconductor (e.g. silicon) is used as the evaporation material, the supply of free terminals can be carried smoothly and arc discharge can be easily maintained between the ionizing electrode and the evaporation source. Therefore, the ionization rate of the evaporated particles is extremely high at 50 to 80%, but if an insulator or a semiconductor similar to this (e.g. boron) is used as the evaporator, the supply of free terminals will not be carried out smoothly and arc discharge will occur. The ionization rate of the evaporated particles was very small, less than a few percent.

The object of this invention is to provide an ion plating device that can increase the ionization rate of evaporated particles of an insulator or a semiconductor similar thereto.

This invention will be explained below based on one embodiment shown in the drawings.

In the figure, 1 is a vacuum chamber, an electron gun section 2 is provided in the lower part of the vacuum chamber, 3 is a crucible for the electron gun section 2, and 4 is a crucible 3.
5 is a filament that generates electrons that bombard the evaporation material 4, and 6 is a power supply that connects the filament with a voltage and current of, for example, 8.5 V and 50 A.

Reference numeral 7 denotes an ionization electrode, which is located outside the vapor path from the crucible 3 to the substrate 10 (described later), and is placed close to the crucible 2, for example, at a distance of 4.5 cm. A positive voltage of 20 to 200V, for example 75V, is applied by the power supply 9.

The substrate 10 is placed above the vacuum chamber 1 so as to face the crucible 3 at an interval of, for example, 19 cm, and a negative voltage of 20 to 1000 V, for example 200 V, is applied to the crucible 2 by a power source 11. be done.

The substrate 10 is attached to the lower end of the rotating shaft 12 and
passes through the earthen wall of the vacuum chamber 1 in an airtight manner, extends to the outside world, and is coupled to the motor 13.

Note that 14 is a heater for heating the substrate 10, 15 is a shutter provided between the substrate 10 and the crucible 3, and 16 is a vacuum chamber exhaust pipe.

Reference numeral 20 denotes a discharge tube, which is provided outside the vacuum chamber 1 and has a gas introduction tube 22 located on an extension of the axis of this tube 20, and this introduction tube 20 passes through the vacuum chamber 1 in an airtight manner. , is extended 1 cm above the crucible 3.

A gas such as argon or nitrogen is fed into the discharge tube 20 via a flow rate regulating valve 24 .

Reference numeral 26 denotes a discharge electrode for ionizing this gas, which is disposed on the wall of the discharge tube 20 along its axis so that its tip is 8 to 12.5 cm away from the center of 3. 20 to 1000 for crucible 2
A positive voltage of V is applied by power supply 28.

A magnet 30 is provided around the outer periphery of the discharge tube 20 so as to generate a 2GO Gauss magnetic flux parallel to the axis of the discharge tube 20 and directed toward the discharge electrode 26 side.

A case will be described in which boron is evaporated onto the substrate 10 using this apparatus.

First, the inside of the vacuum chamber 1 is evacuated to about 10-5㎝ through the piping 16, the flow rate adjustment valve 24 is adjusted, and the inside of the discharge tube 20 is
Argon gas was fed into the discharge tube 2 at a flow rate of 4 cc/min.
The pressure within 0 is set to 10-2 to 10-3}-rel, a positive voltage is applied to the discharge electrode 26, and the filament 5 is heated to 2000
℃ or higher to emit electrons and apply an electron bombardment to the evaporation material 4 in the crucible 3 to evaporate the evaporation material at a rate of 0.03 g/min, while applying a positive voltage of 75 V to the ionization electrode 7. do.

When the vapor pressure reaches 10-2 to 10-3}-rel, electrons move from the evaporation material 4 and the filament 5 to the ionization electrode 7.

At this time, the electrons repeatedly collide with the evaporated particles, and the electrons mostly head toward the ionization electrode 7, although their directions vary.

However, some of it goes to the gas introduction pipe 22.

At this time, since a positive voltage is applied to the discharge electrode 26, these electrons jump into the discharge tube 20.

The electrons that have jumped into the discharge tube 20 collide with argon gas particles within the discharge tube 20, and ionize the argon gas particles into argon ions and electrons.

These argon ions are on the outer peripheral wall side of the discharge tube, that is, on the magnet 3.
0, collides with argon gas particles, and is ionized into argon ions and electrons.

The electrons generated at this time move in a spiral motion perpendicular to the magnetic flux and move toward the discharge electrode 26, and then collide with other argon particles one after another, ionizing them into argon ions and electrons, and these electrons also move in a spiral motion. While doing so, it faces the electrode 26 side and ionizes the argon particles anew.

In this way, argon ions are generated within the discharge tube 20.

These argon ions flow out between the crucible 3 and the ionization electrode 7 via the gas introduction tube 22 due to the pressure difference between the discharge tube 20 and the vacuum chamber 1 .

The outflowing argon ions collide with the evaporated particles from the crucible 3 and ionize them into evaporated particle ions and electrons.

Therefore, the electrons generated by the collision between the evaporated particles and the argon ions are added to the electrons generated from the filament 5 and the evaporated material of the crucible 3, so the number of electrons between the crucible 3 and the ionization electrode 7 increases.

Most of these electrons are directed toward the ionization electrode 7 and an arc discharge is formed, but some of them jump into the discharge tube 20 through the gas introduction tube 22, ionize the argon in the same way as described above, and enter the crucible. 2 and the ionizing electrode 7 to form an arc discharge and ionize the evaporated particles.

Therefore, the number of electrons between the crucible 3 and the ionization electrode 7 increases.

By repeating these steps in a short period of time, the arc discharge between the crucible 3 and the ionization electrode 7 becomes steady, and the ionization of the evaporated particles becomes steady.

At this time, if the substrate 10 is rotated by the motor 13 and a negative voltage of 20 to iooo v is applied to the substrate 10 and the shutter shutter 15 is opened, the ionized evaporated particles will have a large kinetic energy (50 to 2000 volts). eV
) and reach the substrate 10, where ion plating is performed.

In such an ion plating device, the evaporated particles existing between the crucible 3 and the ionization electrode 7 are bombarded with argon ions generated using electrons generated when the evaporated particles are generated, and the crucible is heated. Since the evaporated particles are ionized by generating an arc discharge between the ionizing electrode 7 and the ionizing electrode 7, the evaporation particles can be easily ionized even when an insulator or a similar semiconductor is used as the evaporation material.

By the way, when boron is used as the evaporation material in a conventional high-vacuum arc discharge ion plating device, only a current of 1 to 2 mA flows through the ionization electrode, so the evaporation material is not ionized much, and the formed film is When 30W of ultrasonic vibration was applied, it peeled off within 5 minutes, but with this device, boron was used as the evaporation material and argon gas was used as the gas, and the discharge tube 2
When the potential difference at zero is 100 cm and the current is 6 A, the current flowing through the ionizing electrode 7 increases by four orders of magnitude to 10 to 4 OA, the evaporated material is sufficiently ionized, and the formed film is 3
No peeling occurred even when 0W ultrasonic vibration was applied for 5 hours.

In the above embodiment, the evaporation material was evaporated using an electron gun, but it may also be evaporated using a resistance heating method.

Further, although the discharge tube 20 is provided outside the vacuum chamber 1, the inside of the vacuum chamber may be airtightly partitioned and the discharge tube 20 may be provided in the partitioned portion.

[Brief explanation of drawings]

The figure is a schematic diagram of an ion plating apparatus implementing the ion plating apparatus according to this invention. 2... Electron gun (evaporation source), 7... Ionization electrode, 10... Substrate (deposition target), 20.
...Discharge tube, 22...Gas introduction passage, 2
6... Discharge electrode, 30... Magnet (magnetic field generator).

Claims (1)

[Scope of utility model registration request] An evaporation source that evaporates particles from the evaporation material, an ionization electrode that generates an arc discharge through the evaporation particles to ionize the evaporation particles, and a deposition object to which the ionized evaporation particles adhere are provided in a vacuum chamber. In the ion plating apparatus, a discharge tube is provided adjacent to the vacuum chamber and into which a gas having a pressure higher than the pressure inside the vacuum chamber is supplied, and a space between the discharge tube and the evaporation source and the ionization electrode is provided. a passageway extending into the discharge tube, and a passageway disposed in the discharge tube facing the passageway and facing the evaporation source so as to draw electrons generated by the arc discharge into the discharge tube through the passageway and discharge them through the gas. A discharge electrode to which a voltage is applied, and a magnetic field generator disposed around the outer periphery of the discharge tube to generate a magnetic field that directs electrons generated during the discharge toward the discharge electrode while rotating them. plating equipment.