JPH03247748A - Plasma treating device - Google Patents

Abstract

PURPOSE:To efficiently treat different materials with plasma in parallel by time-sharingly supplying a driving pulse voltage to plural treating chambers through a control means in accordance with the material in each treating chamber to generate a DC glow discharge. CONSTITUTION:The materials 7A and 7B respectively placed in plural vacuum vessels 1A and 1B are treated with plasma utilizing a DC glow discharge. In this plasma treating device, a driving pulse voltage is impressed on the vessels 1A and 1B from one DC power source 2 through switching circuits 3A and 3B. The driving pulse voltage is time-dividedly supplied by a control system consisting of a control unit 4 and a pulse control part 5 based on the predetermined voltage control pattern and signals from the temp. detectors 6A and 6B of the vessels 1A and 1B in accordance with the materials 7A and 7B. Consequently, different materials are treated in the plural treating chambers simultaneously and in parallel, and the surface treating process is reduced.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides a plasma processing apparatus 1 using DC glow discharge.
For example, the present invention relates to plasma processing apparatuses such as ion nitriding apparatuses, gas carburizing apparatuses, and ion brating apparatuses.

(Prior Art) As an example of this type of apparatus, an apparatus having an ion nitriding function will be described with reference to FIG.

Here, three vacuum containers 41A are used as processing chambers.

41B, 41. DC voltage is selectively supplied to these vacuum vessels from one DC power supply 42.

A vacuum pump 43 for rough pumping and a regular vacuum pump 44 are connected to the vacuum container 41A via valves, and an N2 gas supply source 45. Ar gas supply source 46. N2 gas supply source 4
7 is connected.

The same applies to the vacuum containers 41B and 41C.

When performing ion nitriding treatment in the vacuum container 41A, as is well known, the material to be treated is placed in the vacuum container 41A and then evacuated using vacuum pumps 42 and 43. When a predetermined reduced pressure state is obtained, the N2 gas supply source 45. Ar gas supply source 46. H from the N2 gas supply source 47 to the vacuum container 41A.
2, Ar.

N2 gas is supplied at an arbitrary ratio, and then the DC power supply 42
H2, Ar by supplying DC voltage from.

Produces DC glow discharge in N2 gas atmosphere.

The nitriding process begins.

(Problem to be solved by the invention) By the way, this device supplies power to any of the vacuum vessels 41A to 41C by switching a switch from the DC power supply 42, and only one vacuum vessel can be operated at any time. It is.

On the other hand, in the case of an apparatus equipped with a plurality of vacuum vessels, it is desirable to be able to process different amounts of interest in parallel.

However, if the material to be processed differs, the processing time will of course change.
The temperature increase rate and driving voltage are also different. For example, lightweight materials such as thin stainless steel plates can be heated quickly and require low driving voltage;
Heavy weight devices require a slow rise and high drive voltage. For these reasons, it has not been possible to process different materials to be processed in parallel using conventional devices.

An object of the present invention is to provide a plasma processing apparatus that can process different materials to be processed in parallel in a plurality of processing chambers by improving a power supply means.

(Means for Solving the Problems) A plasma processing apparatus according to the present invention includes a plurality of processing chambers in which processing proceeds simultaneously, and a single power supply is supplied to the plurality of processing chambers at a time according to the material to be processed in each processing chamber. The present invention is characterized in that it includes a control means that supplies a pulsed driving voltage in parts.

(Function) The control means in the present invention controls the voltage supplied to each processing chamber based on a control pattern determined in advance according to the material to be processed in each processing chamber. The voltage is controlled by changing the generation period and the number of pulse voltages.

(Example) An example of the present invention will be described with reference to FIGS. 1 to 3.

In FIG. 1, in order to make the explanation easier to understand, a case will be described here in which there are two vacuum vessels as processing chambers.

It has one DC power supply 2 as a power supply system to the vacuum vessels IA,], B, and a pulsed drive voltage is supplied to the vacuum vessels IA, IB in a time-sharing manner via switching circuits 3A, 3B. . The pulsed drive voltage is controlled by the control unit 4. as described later. This is performed by a control system based on the pulse control section 5. The control unit 4 performs control to draw a predetermined voltage control pattern depending on the material to be processed, and also performs voltage control based on signals from temperature detectors 6A and 6B installed in each vacuum vessel IA and IB. conduct.

The exhaust system and various gas supply systems for each vacuum vessel IA and IB are in the fourth
Since it may be the same as that shown in the figure, the explanation of the illustration will be omitted.

The control unit 4 is configured to be able to set a plurality of types of power supply patterns depending on the material to be processed, and controls the pulse control section 5 based on the set power supply pattern to control the switching circuit 3A.

Controls the number of cycles of the pulsed drive voltage that is the output of 3B. Note that the pulse generation time range for the vacuum vessel IA and the pulse generation time range for the vacuum vessel IB are made not to overlap.

FIG. 2 shows an example of a power supply pattern set in the control unit 4. As shown in FIG. When the material to be processed 7B accommodated in the vacuum container IB is larger than the material to be processed 7A accommodated in the vacuum container IA, the power supply pattern supplied to the vacuum container IA (Fig. 2 a) The power supply button (FIG. 2b) supplied to the vacuum vessel IB also becomes larger. In FIG. 2, the shaded area indicates the temperature increasing or decreasing process, and the area parallel to the 1-time axis indicates the soaking process.

Next, the operation will be explained.

Vacuum container], A, and 1.8 are the materials to be processed 7A and 7B, respectively.
After accommodating the gas, setting the power supply pattern, and performing predetermined exhaust operations and gas supply operations.

The control unit 4 starts supplying power. control unit 4
First, in order to cause the vacuum vessel 1A to draw the rising pattern shown in FIG. 2(a), the pulse controller 5 is controlled to apply a pulsed voltage with a large number of pulses per unit time to the vacuum vessel IA. supply

When the heating of the vacuum container IA is completed, the control unit 4 reduces the number of pulses per unit time by a predetermined number and supplies the vacuum container IA with a predetermined number so that the soaking process is performed.

Control unit 4 also. In order to start raising the temperature of the vacuum vessel IB, the pulse controller 5 is controlled based on the pattern shown in FIG. On/off control.

Figure 3 shows vacuum vessel IA undergoing soaking treatment (Figure 3a), and Q
The pulsed driving voltage during heating of the empty container IB (Fig. 3b) is shown.

Control unit 4 also. Feedback control is performed using detection signals from temperature detectors 6A and 6B.

That is, when the temperature inside the vacuum container fluctuates for some reason, the pulse controller 5 is controlled to compensate for this temperature fluctuation. Note that if there is little temperature variation within the vacuum container, the above-mentioned feedback system is not necessary.

Furthermore, the present invention is not limited to the above-mentioned embodiments, but can also be realized by controlling the widths of the pulsed voltages supplied to each processing chamber so that they do not overlap in time. In this case, the pulse width is controlled by the switching circuit 34A.

This can also be realized by an ignition control means that controls the conduction angle of 34B.

(Effects of the Invention) As described above, according to the present invention, by providing a control means that can individually control the voltage from one DC power supply to a plurality of processing chambers, Even the materials to be treated can be surface-treated in parallel and at the same time, making it possible to significantly shorten the number of steps required for one surface heat treatment.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, and FIG.
A diagram showing an example of a salt cover turn supplied to the vacuum container shown in the figure, FIG. 3 is a diagram showing an example of a pulsed voltage supplied to the vacuum container shown in FIG. 1, and FIG. A schematic configuration diagram of a conventional plasma heat treatment apparatus. In the figure, IA and IB are vacuum containers, and 2 is a DC power supply. 3A and 3B are switching circuits, 4 is a control unit, 5
is a pulse control unit, and 6A and 6B are temperature detectors. 7A and 7B are materials to be processed.

Claims (1)

[Claims] 1) A plasma processing apparatus that uses DC glow discharge is equipped with multiple processing chambers in which processing proceeds simultaneously, and pulses are applied to these multiple processing chambers from one power source in a time-sharing manner according to the material to be processed in each processing chamber. What is claimed is: 1. A plasma processing apparatus comprising: a control means for supplying a driving voltage of 1.