JPH06293967A - Ion shower device - Google Patents

Abstract

PURPOSE:To prevent the charge up of an insulator substrate by providing the outer periphery of the substrate with a secondary electron supplying metallic body applied with a negative voltage and neutralizing the charges accumulated on the substrate at the time of subjecting the thin film formed on the insulator substrate to ion shower doping. CONSTITUTION:Reactive gas and/or inert gas is introduced into a plasma chamber 1 and a filament 3 is lighted. An arm discharge is generated between this filament 3 and the inside wall of the plasma chamber, by which the plasma is generated. This plasma is drawn out by a drawing out electrode system 8 and is emitted as an ion beam 11 to the glass substrate side in a chamber 7, by which the amorphous silicon thin film formed on the substrate 6 is doped. The substrate 6 is provided with a metallic plate 10 as the secondary electron supplying body applied with the negative voltage by a variable DC power source 9 around the substrate 6 at this time. This metallic plate is irradiated with a part of the ion beam 11 to release the secondary electrons e<-1>, by which the positive charges of the substrate 6 are neutralized. As a result, the charge up of the glass substrate 6 is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion shower device for preventing an insulator substrate from being charged up.

[0002]

2. Description of the Related Art In a process of manufacturing a liquid crystal display, an ion beam obtained by converting a reactive gas into plasma is doped into a thin film amorphous silicon on a glass substrate. There is an ion shower device as a device for performing such ion beam doping.

FIG. 2 is a conceptual diagram of a conventional ion shower device.

In FIG. 1, the ion shower device comprises a bucket type plasma chamber 1, an inlet 2 for introducing a reactive gas such as PH ₃ into the plasma chamber 1, and a cathode provided above the plasma chamber 1. Filament 3 as
A filament power supply 4 connected to the filament 3 for lighting the filament 3, a high-voltage power supply 5 for generating an arc discharge between the filament 3 and the inner wall of the plasma chamber 1 as an anode, and the plasma chamber 1 A chamber 7 for housing a glass substrate 6 provided on the emitting side (lower side in the figure) on which an amorphous silicon thin film is formed;
An extraction electrode system 8 is provided between the chamber 7 and the plasma chamber 1 for extracting the plasma generated in the plasma chamber 1 to dope the amorphous silicon thin film on the glass substrate 6.

The glass substrate 6 is placed in the chamber 7 of such an ion shower apparatus, the plasma chamber 1 and the chamber 7 are evacuated by a vacuum pump (not shown), and a reactive gas is introduced into the plasma chamber 1. It is introduced, and this reactive gas is arc-discharged into plasma. After the reactive gas is turned into plasma, a predetermined voltage is applied to the extraction electrode system 8 to extract ions, and the glass substrate 6 is irradiated with the obtained ion beam to perform ion shower doping.

[0006]

In the ion shower device described above, however, the glass substrate itself is an insulator and cannot be directly grounded. Therefore, when the amorphous silicon thin film on the glass substrate is doped with an ion beam, positive ions accumulate (charge up) on the glass substrate, and the amorphous silicon thin film is destroyed.

Therefore, in this type of ion shower device for manufacturing a liquid crystal display, electrons (minus ions) obtained by ionizing a neutral gas in the chamber with a gas pressure higher than that of an ordinary ion shower doping device are used.
It is performed to neutralize the positive ions accumulated on the glass substrate.

However, depending on the type of gas, there are some that are easily ionized and some that are difficult to ionize, and depending on the ion species to be doped, the ionization of the gas alone may not be sufficient to charge up.

Therefore, an object of the present invention is to solve the above problems and to provide an ion shower device capable of preventing charge-up of an insulating substrate.

[0010]

In order to achieve the above object, the present invention is an apparatus for performing ion shower doping on a thin film formed on an insulating substrate such as glass. A secondary electron supply metal body, which is grounded or to which a negative voltage is applied, is provided for neutralizing the electric charge accumulated in.

[0011]

According to the above structure, when the thin film formed on the insulator substrate is subjected to ion shower doping, positive charges are accumulated in the insulator substrate. However, secondary electrons are emitted by collision of ions with a secondary electron supply metal body that is grounded or to which a negative voltage is applied, and the secondary electrons neutralize the positive charges accumulated on the insulator substrate. , Charge up of the insulating substrate is prevented.

[0012]

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a conceptual diagram of an embodiment of the ion shower apparatus of the present invention. The same reference numerals are used for the members common to the ion shower device shown in FIG.

In the figure, an ion shower device is a bucket type plasma chamber 1 and a reactive gas and / or an inert gas (eg PH ₃ / H ₂ ) connected to the plasma chamber 1.
Inlet 2 for introducing the gas into the plasma chamber 1, a filament 3 as a cathode provided in the upper part of the plasma chamber 1 for converting the reactive gas and / or the inert gas into plasma, and the filament 3 connected to the filament 3. A filament power source 4 for lighting the filament 3, a high-voltage power source 5 for generating an arc discharge between the filament 3 and the inner wall of the plasma chamber 1 serving as an anode, and an exit side of the plasma chamber 1 (in the figure). A chamber 7 which is provided on the lower side) and grounded, and which accommodates a glass substrate 6 as an insulator substrate on the surface of which thin film amorphous silicon is formed;
An extraction electrode system 8 provided between the chamber 7 and the plasma chamber 1 for extracting the plasma generated in the plasma chamber 1 and injecting the plasma into the glass substrate 6, and a variable DC power supply 9 provided around the glass substrate 6 provide a negative voltage. Voltage was applied 2
It is composed of a metal plate 10 as a secondary electron supplier.

The shape of the metal plate 10 is, for example, a frame shape, but is not limited to this and may be a ring shape as long as it is a shape corresponding to the shape of the glass substrate.

Next, the operation of the embodiment will be described.

When such an ion shower doping apparatus is operated, a reactive gas and / or an inert gas is introduced into the plasma chamber 1, the filament 3 is turned on, and the filament 3 and the inner wall of the plasma chamber 1 are lit. Arc discharge occurs and plasma is generated. The plasma generated in the plasma chamber 1 is extracted by the extraction electrode system 8 and emitted as an ion beam 11 to the glass substrate 6 side in the chamber 7. Most of the ion beam 11 extracted from the plasma chamber 1 is doped into the amorphous silicon thin film formed on the glass substrate 6. Due to this doping, positive charges are accumulated on the glass substrate 6.

On the other hand, a part of the ion beam 11 extracted from the plasma chamber 1 is applied to the metal plate 10. The irradiation of the ion beam 11 causes the ions 11 a to collide with the metal plate 10 to emit secondary electrons e ⁻ . The secondary electrons e ^-
Is neutralized with the positive charge of the glass substrate 6, the glass substrate 6
Charge up is prevented.

As described above, according to this embodiment, when the thin film formed on the insulating substrate is subjected to ion shower doping, positive charges are accumulated in the insulating substrate. However, secondary electrons are emitted by collision of ions with a secondary electron supply metal body that is grounded or to which a negative voltage is applied, and the secondary electrons neutralize the positive charges accumulated on the insulator substrate. , The insulator substrate is prevented from being charged up, and the thin film is prevented from being broken.

In the present embodiment, the case where a negative voltage is applied to the metal plate has been described, but the present invention is not limited to this, and metals such as molybdenum and tantalum which emit a large number of secondary electrons are grounded. You may comprise. Further, although the case where the glass substrate is used as the insulating substrate has been described, it is needless to say that the present invention is not limited to this.

[0021]

In summary, according to the present invention, the following excellent effects are exhibited.

(1) Charge-up of an insulating substrate such as glass is prevented.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of an embodiment of the ion shower device of the present invention.

FIG. 2 is a conceptual diagram of a conventional ion shower device.

[Explanation of symbols]

 6 Insulator Substrate (Glass Substrate) 10 Secondary Electron Supply Metal (Metal Plate)

Claims (1)

[Claims] 1. In a device for performing ion shower doping on a thin film formed on an insulating substrate such as glass, the outer periphery of the insulating substrate is grounded to neutralize electric charges accumulated in the insulating substrate. Or negative voltage is applied 2
An ion shower device comprising a secondary electron supply metal body.