JPS6135561Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a glow discharge generating device equipped with discharge detection means.

Recently, devices that perform sputtering, etching, plating, etc. using glow discharge have been in the spotlight. FIG. 1 is a schematic diagram of a high frequency ion plating device shown as an example of such a glow discharge generating device. Reference numeral 1 denotes an exhaust chamber, and a substrate 2, an evaporation source 3, and a high-frequency coil-shaped electrode 4 are arranged at appropriate positions within the exhaust chamber. Said substrate 2
A negative DC voltage is applied from a DC power supply 5 to the board forming the evaporation source 3, and heating AC power is applied from a heating AC power supply 6 to the board forming the evaporation source 3. Further, high frequency power is applied to the high frequency coiled electrode 4 from a high frequency power source 8 via a matching circuit 7 for matching the impedances on the high frequency power source side and the load side. Note that S is a shield. In such a device, first, the inside of the exhaust chamber 1 is removed by the exhaust device 9.
The exhaust chamber 1 is evacuated to about 10 ^-5 Torr, and then, for example, argon gas is introduced into the exhaust chamber 1 from the gas supply device 10 to bring the inside of the exhaust chamber 1 to about 10 ^-3 Torr. When high frequency power is applied from the high frequency power supply 8 to the high frequency electrode 4 in this state, a glow discharge is generated near the electrode. Then, when heating power is applied to the board from the heating AC power source 6 to evaporate the evaporation material, the evaporation particles are ionized in the glow discharge, and the substrate 2
Forms a film on.

Now, in such a glow discharge generator, the operator visually confirms the start of glow discharge,
Next, the operation begins (in the example shown in Figure 1, the operation of the evaporation source), but such glow discharge detection causes a great deal of fatigue to the operator, and the glow discharge generator using this detection method is not suitable for practical use ( It cannot be said that it is suitable for production. Therefore, by placing two electrodes facing each other in the exhaust chamber and applying a DC voltage of about 100 volts, when glow discharge occurs in the exhaust chamber, a current will flow between the opposing electrodes. A method of detecting the start of glow discharge by detecting the start of glow discharge has been proposed, but it requires two electrodes to be provided in the exhaust chamber, a shield must be provided to the lead wire and support of each electrode, and a separate method is required. The necessity of providing a power supply complicates the structure and poses problems in terms of cost.

This idea was made in view of these points,
arranging a high-frequency electrode in the exhaust chamber, applying high-frequency power from a vacuum tube transmitter to the electrode to generate a high-frequency glow discharge in the exhaust chamber, and detecting a plate current flowing through the vacuum tube transmitter; The present invention provides a novel glow discharge generating device that detects the presence or absence of glow discharge based on the detected value.

The present invention was made based on the following principle. That is, when high-frequency power is applied to the high-frequency electrode, if glow discharge does not occur, the impedance on the load side is very large and not much high-frequency power is consumed on the load side, but if glow discharge occurs, The impedance on the load side decreases,
Since high-frequency power is consumed in the glow discharge, for example, if a vacuum tube oscillator is used as the high-frequency power source, the plate current becomes significantly large when the glow discharge occurs. Therefore, by detecting the plate current of the vacuum tube oscillator, it can be determined whether glow discharge is occurring or not.

FIG. 2 is a schematic diagram of a high frequency ion plating apparatus showing an embodiment of the present invention. 1st in the diagram
Items with the same numbers and symbols as those used in the figures indicate the same components. In the figure, 11 is a vacuum tube transmitter, with 12 triode electron tubes and 1 plate power source.
3. Grid power supply 14, filament heating power supply 1
5, Excitation power supply 16, DC cut capacitor 17
and a resonant circuit 18. 19 is a plate current detection circuit, and the plate current flowing through the vacuum tube detected by this circuit is sent to a comparison circuit 20. The comparison circuit has a reference value set in advance, and compares the detected plate current value with the reference value, and when it is smaller than the reference value (when no glow discharge is occurring in the exhaust chamber 1), a signal is emitted. However, when the glow discharge is large (when a glow discharge occurs in the exhaust chamber 1), a signal to activate the heating AC power supply 6 is sent to the power supply control circuit 21. The reference value is determined in consideration of these points since, as described in the principle section, the plate current when no glow discharge is occurring is significantly smaller than when glow discharge is occurring. The comparator circuit 20 also emits a signal when the value is smaller than the reference value, and displays the difference between when it is smaller than the reference value (when glow discharge is not occurring) and when it is larger than the reference value (when glow discharge is occurring). Alternatively, the operator may manually control the heating AC power source 6 according to the display.

In such an apparatus, the inside of the exhaust chamber 1 is evacuated to about 10 ^-5 Torr by the exhaust device 9, and then argon gas is introduced from the gas supply device 10.
Set it to about 10 ^-3 Torr. In this state, high frequency power is applied to the high frequency electrode 4 from the vacuum tube transmitter 11. At this time, the plate current detection circuit 19 detects the plate current flowing through the vacuum tube 12 and sends it to the comparison circuit 20. The comparison circuit compares the plate current with a reference value, and if the plate current is larger than the reference value, sends a signal to the power supply control circuit 21 to activate the heating AC power supply 6. When the power source is activated, evaporation particles are generated from the evaporation source 3, and the particles are ionized in the high frequency glow discharge atmosphere and adhere to the substrate 2.

According to the present invention, the presence or absence of glow discharge can be detected with a very simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a high frequency ion plating device shown as an example of a glow discharge generating device, and FIG. 2 is a schematic diagram of a high frequency ion plating device showing an embodiment of the present invention. 1: Exhaust chamber, 4: High frequency electrode, 8: High frequency power supply, 11: Vacuum tube transmitter, 19: Plate current detection circuit, 20: Comparison circuit.

Claims (1)

[Scope of utility model registration request] A high-frequency electrode is placed in the exhaust chamber, and high-frequency glow discharge is generated in the exhaust chamber by applying high-frequency power from a vacuum tube oscillator to the electrode, and a plate current flowing through the vacuum tube oscillator is detected. A glow discharge generator that detects the presence or absence of glow discharge based on a detected value.