JPH0565632A - Apparatus for coating base with indium/tin oxide - Google Patents

Abstract

PURPOSE: To improve the service life of a target in a device coating a substrate with indium-tin-oxide by providing the clearance between a target to be sputtered and a cathode.

CONSTITUTION: This device coating a substrate with indium-tin-oxide is the one having a power source 10, which is connected to a cathode 5 arranged in a coating chambers 15 and 15a capable of being evacuated and introduced with reactive gases, and in which the cathode 5 is electrically connected to a target 3 to be sputtered, and sputtered grains are precipitated on the substrate 1. The clearance (a) is provided between the target 3 and a U-shaped member 4. In this way, the service life of the target 3 is improved, and operation free from arc discharge can be attained.

COPYRIGHT: (C)1993,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a target having a power source, the power source being connected to a cathode which can be evacuated and into which a reaction gas can be introduced, and the cathode is sputtered. An apparatus for coating an indium-tin-oxide on a substrate, of the type electrically connected and depositing the sputtered particles on the substrate.

[0002]

BACKGROUND OF THE INVENTION Oxide targets are advantageously only sputtered at low speeds (about 5 nm / min) in HF operation, since at high powers significant local evaporation occurs at the target surface. The local evaporation causes a compositional variation of the deposited layer, and at the same time causes the layer to be damaged by the release of molten liquid target particles (sputtering phenomenon). Furthermore, the life of the target is limited to several hours due to the phenomenon that it does not completely disappear even at the low power mentioned above. The target collapses. This problem is especially noticeable in experiments in which layers consisting of oxide high-temperature superconductors are sputtered (German Patent No. 3906954), and therefore the target is electrically insulated and good for high frequency sputtering of the oxide target. It has been proposed to place it on the target support in a thermally conductive manner.

Sputtering devices for depositing a thin layer of a material other than metal on a substrate are known (West German Patent No. 3029567), the device having two electrodes facing each other. One is formed to fix the substrate, and the other electrode is fixed to a target made of a non-metallic material, and atoms forming a thin layer are ejected from the target by ion collision during sputtering.
In this case, the target is composed of at least two vertically overlapping target portions made of ceramic, glass or resin, and an air gap is provided as a heat insulating means between the target and the cathode plate.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the growth of the eroded portion on the surface of the indium-tin-oxide target during the sputtering process to reduce the changes in the specific sputtering rate and the characteristics of the deposited layer. It was an object of the present invention to provide a device suitable for blocking, preventing undesired arc discharge, and enhancing the long-term stability of the process. Increasing long-term stability results in a significant increase in productivity, especially in in-line equipment, since it eliminates the previously required loss of mechanical target cleaning time.

[0005]

According to the invention, according to the invention, the target to be sputtered is held at a distance from the cathode, for which the target is a cathode base, for example a magnet yoke or a U-shaped member,
The solution is provided by the provision of holding means (direct current electrical) connection, for example a pull rod or a support pin.

In an alternative embodiment, a flat heater is arranged between the cathode base, preferably the U-shaped member, and the target, the heating surface of the flat heater being directly on the rear surface of the target. And subjecting the target to controlled heating.

[0007]

The present invention can be implemented in various embodiments. One example thereof will be described in detail with reference to the drawings. The example is a sputtering apparatus for DC sputtering.

FIG. 1 shows a substrate 1 on which a thin layer 2 is to be applied. The substrate 1 faces the target 3 to be sputtered. The target 3 is a plurality of thin support pins 3
0, 30 'and an electrode 5 through a U-shaped member 4 in cross section
Connected to the electrode, which encloses a yoke 6, which is provided between itself and the U-shaped member 4 with three permanent magnets 7,
8 and 9 are enclosed. The polarities of the magnetic poles of the three permanent magnets 7, 8, 9 facing the target are staggered.
Therefore, the south poles of the permanent magnets on both outer sides 7 and 9 respectively generate a magnetic field of an arc shape passing through the target 3 and the north pole of the permanent magnet 8 in the center. The magnetic field compresses the plasma in front of the target 3 and thus has its maximum density where the magnetic field has its arc maximum. Ions in the plasma are accelerated by an electric field formed based on a DC voltage applied from the DC power supply 10. The negative pole of the DC power supply 10 has a conductive wire 28 and two inductors 1
1, 12 are connected to the electrode 5, in which case the conductor 28 is further grounded via two capacitors 29, 31. The electric field is formed perpendicular to the surface of the target 3 and accelerates the positive ions of the plasma in the direction of the target. This causes a large number of atoms or particles to be emitted from the target 3, in particular from the regions 13, 14 where the magnetic field has its maximum, to varying degrees. The sputtered atoms or particles move in the direction of the substrate 1 where they are deposited as a thin layer 2.

The cathode 5 and the target 3 together with the isolation plate 2
The part of the coating chamber 15 which is surrounded by 4 and in this case is arranged immediately before the target 3 is designated by 15a. The isolation plate 24 has an opening 26 on the lower side thereof, and particles emitted from the target 3 through the opening are accelerated toward the substrate 1.

To control the illustrated device, a process computer can be equipped which processes the measured data and emits control commands. The partial pressure value measured in the coating chamber 15, for example, can be supplied to the process computer. Based on these and other values, the process computer can adjust the gas flow rate, for example via valves 18, 19, and adjust the voltage of the cathode 5. The process computer can also adjust all other variables such as cathode current and magnetic field strength. Such process computers are well known and will not be described for their structure.

During the process, argon is introduced into the coating chambers 15 and 15a from the cylinder 16 through the valve 18 and the inflow pipe 21. Further, a cylinder 17 still containing oxygen is provided so that the reactive material can be sputtered, and the cylinder 17 is connected to the coating chambers 15 and 15a via a valve 19 and an inflow pipe 20. ..

As clearly shown in the drawing, the target 3 is not connected to the U-shaped member 4 but to the member 4
Are arranged at a distance a in front of. This member 4
On the basis of the gap between the lower side of the target 3 and the upper side of the target 3, the target 3 is heated to about 200 to 400 ° C. in the coating process, so that the growth of the eroded portion on the lower side of the indium-tin-oxide target 3 is increased. Decisively, and contrary to popular theory, it is reduced.

[Brief description of drawings]

1 is a schematic cross-sectional view of an embodiment of the device according to the invention.

[Explanation of symbols]

1 substrate, 2 layers, 3 target, 4 U-shaped member, 5 electrodes, 6 yokes, 7 permanent magnets, 8
Permanent magnet, 9 Permanent magnet, 10 DC power supply, 1
DESCRIPTION OF SYMBOLS 1 inductor, 12 inductor, 13 sputtering groove (area), 14 sputtering groove (area), 15 coating chamber, 15a coating chamber, 16 gas cylinder, 17 gas cylinder, 18 valve, 19
Valve, 20 inflow pipe, 21 inflow pipe, 24 isolation plate, 26 opening, 27 conductive wire (ground), 28
Conductive wire, 29 capacitor, 30 support pin,
31 capacitors

 ─────────────────────────────────────────────────── —————————————————————————————————————————————————————————————————————————————— In In Inventors Michael Schieler Germany

Claims (2)

[Claims] 1. A coating chamber (15, 15) having a power supply (10), which can be evacuated and into which a reaction gas can be introduced.
a) indium-tin, of the type connected to a cathode (5) located in a) and electrically connected to a target (3) to be sputtered, which deposits the sputtered particles on a substrate (1). A holding means for connecting the target (3) to the cathode base in the device for coating the substrate with oxide, the target (3) to be sputtered being held at a distance (a) to the cathode (5); (30, 31) is provided,
An apparatus for coating a substrate with indium-tin-oxide. 2. A coating chamber (15, 15) having a power supply (10), which can be evacuated and into which a reaction gas can be introduced.
a) indium-tin, of the type connected to a cathode (5) located in a) and electrically connected to a target (3) to be sputtered, which deposits the sputtered particles on a substrate (1). A flat heater is arranged between the cathode base (4) and the target (3) in the device for coating the substrate with the oxide, and the heating surface of the flat heater directly contacts the back surface of the target (3). And a controlled heating of the target, an apparatus for coating a substrate with indium-tin-oxide.