JPS6314863A - Vacuum device - Google Patents

Abstract

PURPOSE:To prevent the influence of a high-frequency component from plasma and to stably execute the generation of a flow discharge, acceleration of electrons and ions, etc., by interposing a high-frequency cut filter between the output part of a DC power source and electrode. CONSTITUTION:The sputtering electrode 33 and substrate holder 35 are provided to a vacuum chamber 31 of a bias sputtering device using a DC power source for biasing the substrate and a voltage is impressed to the substrate holder 36 through the high-frequency cut filter from the DC power source 11 for biasing. The noise of the high-frequency component from the plasma is cut by the high-frequency cut filter 13 here again, by which the bias is stably applied to the electrode 35 to accelerate the ions.

Description

[Detailed description of the invention] relief disaster The present invention relates to a vacuum device equipped with a DC power source.

A DC power source is used to generate plasma and accelerate electrons and ions in a vacuum device. For example, in DC sputtering equipment, a sputtering electrode is installed in a vacuum chamber, and a DC voltage is applied to the sputtering electrode to generate glow discharge. However, due to various reasons, glow discharge suddenly shifts to arc discharge. There are things to do.

One of the reasons for this is that small particles fall on the electrode.
It is conceivable that the current is concentrated at that point due to thermionic emission and transitions to arc discharge. It is also thought that localized gas release or oxidation of the electrode surface may cause the transition to arc discharge.

If arc discharge occurs, a large current will flow and damage the DC power supply, so measures are taken to detect the transition to arc discharge on the output side of the DC power supply and instantly shut off the output.

However, depending on the target used and the sputtering conditions, the output was often interrupted, which caused serious problems in thin film formation. For example, when using a target whose surface is easily oxidized such as AI, or when sputtering by introducing oxygen gas using an oxide target with relatively high resistivity such as IT○, SnO, etc., the output may be cut off. This caused a significant hindrance to film formation.

It can also be used as a DC power source for bias in bias sputtering, or as a DC power source for hot electron acceleration in bipolar sputtering or electron beam evaporation sources.

The voltage tends to become unstable, which has been a problem in terms of automation of vacuum thin film manufacturing equipment.

The present invention relates to a vacuum device capable of generating stable glow discharge and stably accelerating electrons and ions using a DC power source.

The vacuum apparatus of the present invention includes a vacuum chamber in which plasma is generated by electric discharge, an electrode provided in the vacuum chamber to form an electric field in the vacuum chamber, and a DC power supply that applies a DC voltage to the electrode. The vacuum apparatus is characterized in that a high frequency cut filter is interposed between the output part of the DC power source and the electrode.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment in which the present invention is applied to a DC sputtering apparatus, in which a high frequency cut filter 13 is inserted between a vacuum chamber 21 and a DC power supply 11. AC power is introduced from a power switch, passes through an SCR phase control circuit and a power transformer, is converted into DC by a rectifier circuit and a filter circuit, and is applied to a sputtering electrode 23 provided in a vacuum chamber 2 of the DC sputtering apparatus. The output detection circuit detects the output voltage, compares it with a reference voltage, and when the voltage fluctuates beyond a set value, activates the SCR gate drive circuit to cut off the output.

When a transition to arc discharge occurs, the above-mentioned safety circuit operates and the output is cut off, but according to the study conducted by the present inventor, it has been determined that the output side shutoff is activated before the transition to arc discharge occurs. Ta. After careful consideration of the cause, we found that
The electronic circuit on the power supply side malfunctions due to the high-frequency component noise caused by the discharge load, and it detects arc discharge as if it had occurred even though it has not occurred, causing the output side to shut off. It turned out that it was.

In the vacuum apparatus of the present invention, since the high frequency filter 13 is provided, the high frequency component due to the discharge load (plasma) is cut, the above-mentioned malfunction is prevented, and sputtering can be performed stably.

In particular, targets that are susceptible to surface oxidation such as Afl and oxide targets with relatively high resistivity (ITO1Sn
02, etc.), the discharge load tends to be unstable, and the influence of the above-mentioned high frequency components is large, making sputtering by automatic control difficult. However, according to the vacuum apparatus of the present invention, when using such a target, It has also become possible to perform sputtering with high power.

Although a π type filter is shown as the high frequency cut filter 13 in FIG. 1, other types such as a T type filter may be used. Furthermore, a high frequency cut filter can also be inserted on the ground side.

Such adverse effects from plasma are similar to other vacuum devices in which plasma is generated within a vacuum chamber.

FIG. 2 is a diagram showing an embodiment in which the present invention is applied to a bias sputtering apparatus (vacuum apparatus) using a DC power source for biasing a substrate. A sputter electrode 33 and a substrate holder 35 are provided in the vacuum chamber 31, and a voltage is applied to the substrate holder 35 from a bias DC power source 11 via a high frequency cut filter 13. Here too, the high frequency component noise from the plasma is filtered through the high frequency cut filter 13.
By applying a stable bias to the electrode (substrate holder 35), the ions can be accelerated.

FIG. 3 is a configuration diagram showing an embodiment in which a DC power source is used as a power source for accelerating thermionic electrons in bipolar sputtering.

A target electrode 43, a hot cathode 45, and an anode 47 are arranged in the vacuum chamber 41. A DC power source 11 for accelerating thermionic electrons is applied to an electrode (anode 47) in the vacuum chamber 41 via a high frequency cut filter 13, and electrons are accelerated by this electric field.

FIG. 4 is a configuration diagram showing an embodiment in which a DC power source is used for accelerating thermionic electrons in an electron beam evaporation source. A DC power source 11 is connected to an electron beam evaporation source 50 installed in a vacuum chamber 51 via a high frequency cut filter 13 . Electrons generated from the hot cathode 53 are accelerated by this electric field and reach the anode 55 (electrode).

According to the present invention, when a DC power source is connected to a vacuum device in which positive energy is generated in a vacuum chamber in order to generate glow discharge or accelerate electrons and ions.

By inserting a high frequency cut filter between the vacuum device and the DC power supply, the influence of high frequency components from the plasma can be prevented, and the generation of glow discharge and the acceleration of electrons and ions can be performed stably.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention. FIGS. 2, 3, and 4 are configuration diagrams showing other embodiments of the present invention. 11...DC power supply 13...High frequency cut filter 21.31.41.51...Vacuum chamber 23...Sputter electrode

Claims (1)

[Claims] 1. In a vacuum apparatus comprising a vacuum chamber in which plasma is generated by electric discharge, an electrode provided in the vacuum chamber to form an electric field in the vacuum chamber, and a DC power source that applies a DC voltage to the electrode, the DC power source A vacuum device characterized in that a high frequency cut filter is interposed between the output section and the electrode.