JP2001081555A - Thin film deposition device and shunting arc discharge electrode device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remarkably increase the evaporating quantity and ion quantity and to improve the productivity by generating shunting arc discharge by an electrode of a wide area and evaporating and ionizing an electrode material. SOLUTION: In a thin film deposition device provided with at least one or more electrodes 3 generating shunting arc discharge in a treating vessel 2 and an arc power source 4 making an arc current for generating shunting arc to flow through the electrode 3, the electrode 3 is composed in such a manner that at least one or more electrically conductive introducing part 16 generating shunting arc discharge are connected to an electrically conductive electrode body 12 composed of an evaporated and ionized material, and the arc power source 4 is connected to the electrode 3 so as to feed an arc current to the electrode body 12 and the introducing part 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus for forming a thin film by shunting arc discharge and an electrode apparatus for shunting arc discharge.

[0002]

2. Description of the Related Art References on shunting arc discharge include the Institute of Electrical Engineers of Japan, ED-98-227 (Generation of induced plasma by shunting arc: 199).
(December 2008). In this conventional technique, a shunting arc discharge is generated by applying a pulse current to a conductive ion source, thereby generating ions. On the other hand, by applying a negative pulse voltage to the workpiece,
Ions generated by the ion source are attracted, and ions are implanted into the surface of the object.

[0003] Such ion implantation is performed by generating a shunting arc in an atmosphere of a reactive gas such as nitrogen or methane to excite plasma to ionize the reactive gas.

[0004]

SUMMARY OF THE INVENTION The above prior art is directed to generating ions by using a shunting arc discharge and injecting them into the surface of an object to be processed. In the above-described conventional technology, the ion source is a thin rod-shaped conductor, which is sufficient for ion generation. However, in the case of industrial use, further, in the case of using not only ion implantation but also film formation, The obtained ion amount and evaporation amount are small and productivity is poor. The present invention has been made in view of such a problem, and a shunting arc discharge is generated by an electrode having a large area to evaporate and ionize an electrode material, thereby greatly increasing the amount of evaporation and ion. ,
The purpose is to improve productivity.

[0005]

The present invention employs the following technical means to achieve the above object. That is, a feature of the present invention is a thin film forming apparatus including at least one or more electrodes that generate a shunting arc discharge in a processing container and an arc power supply that supplies an arc current for causing a shunting arc to the electrodes. , The electrode
At least one or more conductive introducing portions for generating a shunting arc discharge are connected to a conductive electrode body made of an evaporative / ionized substance, and the arc power supply is configured to supply an arc current to the electrode body and the introducing portion. Is connected to the electrode so as to supply

According to such a configuration, a shunting arc discharge occurs in the introduction portion and spreads to the electrode body. Since a shunting arc is generated in the introduction portion in this manner, it is not necessary to generate a shunting arc in the electrode body, and therefore, the area of the electrode body made of the evaporated / ionized substance can be increased, and as a result, the electrode body can be formed. It is possible to increase the amount of evaporation and the amount of ions from the material. Also, a plurality of the electrodes are provided in the processing container, each electrode is connected to one arc power supply via a switch, and a current is sequentially supplied to each electrode by the switch from the arc power supply. It is preferable that

In this case, since a plurality of electrodes can be driven by one arc power supply, the cost of the apparatus can be reduced.
Further, in the shunting arc discharge electrode device according to the present invention, a conductive introduction portion that generates a shunting arc discharge by supplying a pulsed arc current is connected to a conductive electrode body made of an evaporated / ionized substance. It is characterized by having been done.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a thin film forming apparatus 1 according to a first embodiment of the present invention. The thin film forming apparatus 1 is mainly provided with an electrode (electrode device) 3 provided in a vacuum vessel 2 as a processing vessel in a state of being electrically insulated from the vacuum vessel 2. Note that the term “thin film formation” as used in the present invention means to include ion implantation into the surface layer of the substrate 5 in addition to the formation of the thin film on the substrate 5 (the substrate 5 may be a revolving jig) as the object to be processed.

The apparatus 1 includes an arc power supply 4 for applying a pulse to the electrode 3 and a bias power supply 6 for applying a negative bias voltage or a negative high-voltage pulse bias to a substrate 5 provided opposite to the electrode 3. Is also provided. Although not shown, the vacuum container 2 is provided with a vacuum pump for evacuating the inside of the vacuum container and a gas supply unit for supplying a reactive gas such as nitrogen or methane into the vacuum container 2 with valves. Connected through. Here, the generation principle of the shunting arc will be described. A material such as a wire or foil placed in a low pressure or vacuum is fixed between the electrodes, and a pulse current is applied. The temperature of the material rises due to the heating, and a particle cloud of atoms and electrons is formed around the material due to evaporation. When the material is metal or the like, it is considered that there are many electrons due to thermionic emission from the surface. As the temperature increases, the resistance of the material increases, and the voltage applied between the electrodes increases with time. When the voltage drop generated between the electrodes reaches the discharge starting voltage of the surrounding medium (reactive gas), a discharge occurs in the medium, and plasma containing the constituent factors of the material is generated, resulting in an arc. At this stage, the current flows through the medium and basically does not flow through the original material. The generated plasma is a shunting arc, and a large amount of material components are present in the plasma.

In order to cause a sharp increase in voltage and heating of the linear material, a pulse discharge such as a capacitor discharge is suitable. Shunting discharge refers to an arc generated around a material or foil to be ionized by heating the foil or material. Here, the description returns to the embodiment. As shown in FIG. 3, the arc power supply 4 is for generating a shunting arc by applying a high pulse current to an electrode 3 connected between its terminals 4a and 4b. This shunting arc is generated under a reactive gas atmosphere injected into the vacuum vessel 3 by the gas supply means.

The shunting arc is generated by the energy stored in the capacitor C (capacity: 20 μF) (the resistance R in the figure is 3 kΩ). The charging voltage of the capacitor is 1.0 to 2.5 kV. Note that arcing easily occurs even when the charging voltage is 500 V. The triggertron 10 is used as a switch element for generating a pulse. The triggertron 10 is a kind of closing switch (close switch), and is a spark gap with a trigger pin.

The operation of this triggertron is as follows (see FIG. 3). A high voltage pulse voltage (output voltage: 10 kV, width: about 2 μs) is input to the trigger pin from the trigger tron driver TD by a signal from the signal generator SG to generate a minute arc, and the charging voltage of the capacitor C causes a spark gap dielectric breakdown. Bring. Subsequent to the release of charge from the capacitor C, heating of the electrode material and formation of a shunting arc are performed. FIG. 3 also shows a bias power supply 6 for applying a negative high-voltage pulse bias to the substrate 5, and the power supply 6 inputs a signal from the signal generator SG to the delay pulse generator DPG and outputs an output voltage. Is input to the pulse modulator PM after a lapse of a predetermined time, and the high voltage output from the output terminal 6a of the pulse modulator PM is fed through the feedthrough FT to the substrate 5 in the vacuum vessel 2.
Is applied. Thereby, ions are extracted from the plasma.

As shown in FIG. 2, the electrode 3 has a conductive electrode body 12 formed in a columnar shape. The electrode body 12 is made of a material (evaporation / ionization substance) for ion implantation or film formation on the surface of the substrate 6, for example, C, Ti, or the like. In addition, a conductive cylindrical electrode body 14 is disposed at a predetermined interval so as to surround the electrode body 12. That is, the electrode body 12 and the cylindrical electrode body 14 are arranged coaxially. The cylindrical electrode body 14 is electrically connected to the electrode main body 12 by introducing portions 16, 16, 16, 16 made of a thin conductive material.

The electrode body 14 and the introduction part 16 are preferably made of the same material as the electrode body 12, but it is sufficient if they are conductive. In the electrode 3, the electrode body 12 and the cylindrical electrode body 14 are connected to the terminals 4a and 4b of the arc power supply 4, respectively, and are connected so that a pulse current flows from the introduction portion 16 to the electrode body 12. That is, the electrode body 12 and the introduction section 16 (and the cylindrical electrode body 14) are connected in series to the power supply 4. The arc power supply 4 may be connected so that a current flows from the electrode main body 12 to the introduction section 16. In FIG. 1, the electrode 3 is placed downward, but may be placed sideways or upward.

The introduction portion 16 is formed to be thinner (having a smaller cross-sectional area) than the electrode body 12. When a current flows through the conductive introduction portion 16 that is thinner than the electrode body 12 in this manner, a shunting arc discharge occurs in the introduction portion 16 and spreads to the electrode body 12. This discharge causes the material of the electrode body 2 to evaporate and ionize, and is deposited or injected on the substrate 5. Here, the number of the introduction portions 16 may be one, but if a plurality of the introduction portions 16 are provided as shown in FIG. 2, a discharge can be efficiently generated. In addition, discharge can be uniformly generated over the entire surface of the electrode body 12 having a large area.

As a result, the amount of evaporation of the material from the electrode body 12 and the amount of ions are greatly increased. In addition, the introduction unit 16
Is also preferably short. As described above, when the number is short and the number is large, more energy is used, which is advantageous from the viewpoint of efficiency. Further, it is preferable to arrange the introduction portion 12 so as to extend radially from the electrode main body 12 from the viewpoint of more uniformly generating the discharge. In particular, such a radial shape is preferable because plasma is emitted in front of the electrode body 12.

The diameter of the introduction section 16 is about 2 mm.
The length (gap length) L is preferably about 10 to 40 mm. The diameter R of (the front surface of) the electrode body 12 is 20 to 20.
About 70 mm is suitable. For example, the length L of the introduction portion 16 can be 10 mm, and the diameter R of the electrode can be 70 mm. Further, the length L of the introduction section 16 is set to 40 mm,
The diameter R of the electrode body 12 can be set to 70 mm.
However, it is not limited to such a size.
In this case, in other words, the configuration of the electrode 3 is, in other words, an electrode body 12 connected to one terminal of the arc power supply 4 and made of an evaporative / ionized substance, and an electrode connected to the other terminal of the arc power supply 4. Predetermined spacing (gap) with body 14
It can be said that the conductive introduction part (rod) 16 for generating a shunting arc is connected between the electrode body 12 and the electrode body 14.

Furthermore, in other words, the configuration of the electrode 3 can be said to mean that the holder (electrode main body) 12 holding the rod 16 for generating the shunting arc is made of an evaporative / ionized substance. FIG. 4 shows a second embodiment of the present invention. The electrode 3 here is the electrode body 1
The annular electrode body 15 is arranged so that the axis is aligned with the front surface 12a of the second electrode 2 at an interval, and an introduction portion 16 is provided between the front surface of the electrode body 12 and the annular electrode 15. In this case, the arc is smoothly moved to the front surface 12a of the electrode main body, and the efficiency is high.

FIG. 5 shows a thin film forming apparatus 1 according to a third embodiment of the present invention. Here, a plurality of electrodes 3a, 3b, 3c are provided in the vacuum vessel 2. Each electrode 3
a, 3b, and 3c are connected to one arc power supply 4 via a pulse switch 18. The pulse switch 18 sequentially switches pulses generated by the arc power supply 4 and sequentially supplies the pulses to the electrodes 3a, 3b, 3c as shown in FIG. By providing the pulse switch 18 in this manner, a plurality of electrodes can be driven by one power supply 4, and the apparatus cost can be reduced.

The present invention is not limited to the above embodiment. That is, for example, although the introduction portion 16 is exemplified as a linear shape, a shunting arc can be generated even when the introduction portion has a foil shape. That is, the introduction portion may have a shape in which the resistance is increased so as to be easily heated by an electric current (for example, the cross section is reduced by making it thinner or thinner).

[0021]

As described above, according to the present invention, the amount of evaporation and the amount of ions from the electrode can be greatly increased, and the productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a thin film forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a plan view of an electrode (electrode device) as viewed in the direction of arrow A in FIG.

FIG. 3 is a circuit block diagram of an arc power supply and a bias power supply.

FIG. 4 is a partial cross-sectional side view of an electrode according to a second embodiment of the present invention.

FIG. 5 is a conceptual diagram of a thin film forming apparatus according to a third embodiment of the present invention.

FIG. 6 is a timing chart of pulse supply to each electrode.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thin film forming apparatus 2 Vacuum container 3 Electrode (electrode device) 4 Arc power supply 5 Substrate (work) 6 Bias power supply 12 Electrode main body 14 Cylindrical electrode body 15 Toroidal electrode body 16 Introducing part 18 Pulse switch

Claims (3)

[Claims] At least one electrode (3) for generating a shunting arc discharge in a processing vessel (2);
In the thin film forming apparatus provided with an arc power supply (4) for supplying an arc current for causing a shunting arc to the electrode (3), the electrode (3) is a conductive electrode body (12) made of an evaporative / ionized substance. The arc power supply (4) is connected to the electrode body (12) and the introduction section (16) by connecting at least one or more conductive introduction sections (16) for generating a shunting arc discharge. A thin film forming apparatus, which is connected to the electrode (3) so as to supply an arc current. 2. A plurality of electrodes (3, 3, 3) are installed in a processing vessel (2), and each electrode (3) is connected to one arc power supply (4) via a switch (18). Each electrode (3) has a switch (18) from the arc power supply (4).
2. The thin film forming apparatus according to claim 1, wherein the current is sequentially switched and supplied. 3. A conductive introduction part (1) that generates a shunting arc discharge by supplying an arc current to a conductive electrode body (12) made of a vaporized / ionized substance.
6), wherein the shunting arc discharge electrode device is connected.