JPS6328871A - Plasma cvd treating device - Google Patents

Abstract

PURPOSE:To form a uniform coated film by arranging plural sets of opposed cathode plate and anode plate at regular intervals in a vacuum vessel provided with a heating means to uniformize the temp. of a material to be worked and the flow of a gas. CONSTITUTION:A cathode body 2, an anode body 3, and a heater 4 to be heated by an electric power source 6 are provided in plural stages at regular intervals in the vacuum vessel 1 provided with a gas supply port 1b and an exhaust port 1a to form the plasma CVD treating device. The material 5 to be worked is placed on the cathode body 2, heated by the heater 4 to about 550 deg.C, and coated with TiN, etc. The temp. of the material 5 to be worked is kept constant by this mechanism, and a uniform coated film can be formed. Besides, when a heating means is provided at the uppermost stage and the lowermost stage of the vessel 1 and further a temp. controller is furnished to each heating means, the temp. of the whole device can be uniformized. Since the electrode bodies 2 and 3 serve as the heating means, the throughput can be increased.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a plasma CVD processing apparatus.

(Conventional technology) Plasma surface treatment is applied to various parts such as watch cases, cufflinks, and tie clips to coat the surfaces of these parts with functional coatings that provide corrosion resistance, abrasion resistance, and aesthetic appeal. Formation is taking place.

As a method for forming this functional film, the object to be treated is subjected to plasma CVD.
It is set in the D processing equipment, generates plasma under a predetermined pressure while flowing the desired reaction gas and carrier gas into the equipment, and forms the desired functional film on the salvageable surface of the object to be processed. be.

Conventionally, such a plasma CVD processing apparatus is disclosed in Japanese Patent Application Laid-Open No. 58-164777 (Japanese Patent Application No. 57-45).
There is a plasma CVD processing apparatus used in a method of forming a coating on a metal workpiece as shown in the specification of No. 710).

This device consists of a plurality of cathode plates and anode plates arranged facing each other at intervals in a vacuum container equipped with a gas supply port, an exhaust port, and a heating means on the vessel wall.

(Problems to be Solved by the Invention) In the above-mentioned conventional method, the workpiece is heated by a heater made of molybdenum or tungsten from the outside of the electrode plate on which the workpiece is placed. However, according to this heating method, the workpiece is heated non-uniformly, and the temperature of the workpiece farther from the heating means is lower than that of the workpiece closer to the heating means. In addition, gases such as reaction gas and carrier gas flow into the equipment, but because the scraping body is plate-shaped, the gas flow is uneven, and the gas does not flow uniformly to the workpiece. . The influence of these non-uniformities in temperature and gas flow increases as the device becomes larger. As described above, in conventional plasma CVD processing equipment, the heating temperature and/or gas flow to the workpiece are non-uniform, resulting in non-uniformity in film thickness, film quality, etc. during film formation. .

Therefore, an object of the present invention is to solve the above-mentioned problems and provide a plasma CVD processing apparatus capable of forming a uniform film.

[Structure of the Invention] (Means for Solving the Problem) In order to achieve the above object, the present inventors focused on making the temperature of the workpiece and the flow of gas uniform, and discovered the following invention. Ta.

Firstly, the plasma CVD processing apparatus of the present invention is characterized in that a cathode body and/or anode body and a heating means are arranged in multiple stages at intervals in a vacuum container equipped with a gas supply port and an exhaust port. be.

In the above invention, since the heating means is arranged parallel to the scraper, it is possible to uniformly heat the workpiece placed on the scraper. This allows the temperature of the workpiece to be kept constant.

Generally speaking, in order to make the temperature of the entire apparatus uniform, heating means are provided at the top and/or bottom of the container. This also makes it possible to heat the workpieces at the top and/or bottom where the temperature tends to be non-uniform.

In order to roughly equalize the temperature of the entire device, each heating means is provided with a temperature control device.

Thereby, each heating means can be arbitrarily controlled, and the heating temperature of the workpiece can be controlled more accurately, and the temperature of the entire apparatus can be made uniform.

This is because conventionally, the temperature of all the heating devices was controlled by one temperature control device, which sometimes made it difficult to make the temperature of the entire device uniform.

Generally speaking, in order to uniformly form a film, the flow of gas is made uniform. First, it is conceivable to provide a gas passage hole for any one of the anode body, cathode body, and heating means that obstructs the flow of gas to improve the flow of the gas. This is because the heating means used was a molybdenum plate or a tungsten plate, for example, which obstructed the flow of gas from below and prevented the gas from flowing uniformly to the workpiece placed on the scraper. This is because there was a case. This flow port is an opening that is large enough to prevent the workpiece from falling, and its shape does not matter.

For example, a mesh-like material is also possible.

Furthermore, by using a sheath heater as the heating means, good thermal efficiency can be obtained without interfering with the flow of gas.

In general, the present inventors have developed a method to cope with the reduction in the processing capacity of a vacuum container with a limited internal volume due to an increase in the size of the device due to the fact that the cathode body, the anode body, and the heating means are each provided independently. As a result of further research, it was discovered that when a sheath heater is used as the heating means, the protective tube of the sheath heater can also serve as a scraper.

That is, a vacuum container equipped with a gas supply port and an exhaust port,
The device is characterized in that a plurality of cathode bodies and anode bodies are arranged at intervals, and the cathode body and/or the anode body also serve as heating means.

In this invention, a sheath heater is preferred. This is a protective tube made of stainless steel, etc., with a heating element installed in the center, and filled with an insulator such as magnesia or zirconia.
This protective tube is used as a scraping body.

In the present invention, the cage that does not also serve as a heating means is provided with a communication port so that the gas flows uniformly, or heaters are provided roughly at the top and/or bottom step, and each is provided with an independent temperature control device. This allows the gas and temperature to be made uniform.

In the above case, all of the protective tubes of the sheath heater are cathode bodies and/or anode bodies.

However, since the top and/or bottom heaters are also used as scrapers, the heaters may become dirty. Therefore, by making the top and/or bottom heaters independent from the beaters that also serve as scrapers, and by connecting the heater's protective tube to the ground instead of using it as a scraper, or keeping it insulated, the sheathed heaters can be prevented from becoming dirty. can be significantly reduced.

In the above invention, a direct current is used as the power source for the scraping body, and the scraping body is used as a cathode or an anode, and the workpiece placed on the scraping body is also used as a cathode or an anode to form a film. . Using direct current as the power source for the scraper requires a direct current circuit, which makes the power source larger and more expensive.

Since film formation is also possible with alternating current discharge, an alternating current power source can be used as the power source for the scraper, making it possible to reduce the size, weight, and cost of the power source.

The coating may be formed with the workpiece placed on the complement, but the same effect can also be obtained by suspending the workpiece from the scraper.

(Function) In the present invention, since the heating means is arranged parallel to the scraper, the entire surface of the scraper can be heated uniformly. Therefore, the temperature of the workpiece placed on the complement becomes uniform. In addition, by arranging the heating means at the top and/or bottom stage of the equipment and by providing each heating means with a temperature control device, the temperature of the entire equipment, that is, the temperature of the workpiece, can be made uniform. can.

Furthermore, by serving as a cathode body and/or an anode body, the processing capacity can be increased in a vacuum vessel with a limited internal volume.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 As shown in FIG. 1, a vacuum container 1 equipped with a gas supply port 1b and an exhaust port 1a has three stages of a cathode body 2, an anode body 3, and a heater 4 made of a molybdenum plate heated by a power source 6. Place the workpiece 5 on the victim body of the plasma CVDff1 processing device.
Immediately thereafter, the film was heated to about 550° C. using a heater and coated with TiN.

For comparison, the cathode body 2 was heated from the outside with a heater 4 as shown in FIG.

As a result, in the plasma CVD processing apparatus of the present invention, the temperature difference between the workpieces on the lowermost cathode body was within about 100°C. Also, the device shown for comparison is approximately 150'
There is a temperature difference, and the temperature is made uniform by the heater.

Further, when the anode body 3 was placed outside the cathode body 2 as shown in FIG. 2, the same coating was applied, and the temperature was made uniform in the same way as above.

In the plasma CVD processing apparatus as shown in FIGS. 1 and 2, the positive and negative film bodies are insulated from the vacuum vessel, so
No electricity flows in a vacuum container. Therefore, there is less risk of electric shock and less staining of the container and inner walls.

Example 2 A flow port was provided in a heater made of a cathode body, an anode body, and a molybdenum plate in the same plasma CVD processing equipment as in Example 1, and the workpiece was coated with TiN. I did it.

As a result, compared to conventional plate-shaped devices, the device of the present invention allows gas to be handled without being hindered by negative or positive electrode plates or heaters. The gas flowed uniformly through the material, and the quality and thickness of the TiN film became uniform. Additionally, gas can now flow uniformly to the workpiece placed in the center of the ladder, making it possible to increase the size of the device.

Example 3 In a plasma CVD processing apparatus similar to Example 1, negative,
An opening was provided in the positive print body as in Example 2, and a sheath heater was used as the heater. As a result, compared to the heater made of a molybdenum plate with openings as in Example 2,
The gas flow improved considerably, and a film with uniform quality and thickness was obtained.

Example 4 As shown in FIG. 3, in the same plasma CVD processing apparatus as in Example 1 (FIG. 1), a power source 6 for the heater 4 was provided for each heater. The temperature of each heater was controlled by this power source 6, so that the temperature of the workpiece was kept constant.

As a result, when heated at about 550'C with a heater, the temperature difference between the workpiece on the pole body was within about 70°C. Further, compared to the first embodiment in which one control means is used for a plurality of heaters, the temperature was about 100° C., the effect of the control device for each heater on making the temperature uniform is large.

Example 5 As shown in FIG. 4, plasma CVD similar to Example 4 was carried out.
A heater 4 was provided at the bottom of the processing device. At this time as well, the heater 4 has its own temperature control means 6. When coating was carried out by heating to a temperature of about 550°C with a heater, the temperature difference in the apparatus of the present invention was about 60°C. In Example 4, in which no heater was installed at the bottom stage, the temperature was about 70°C, and the effect of the heater at the bottom stage was great.

In this embodiment, as in Examples 2 and 3, the effect of making the coating more uniform can be improved by providing openings in the negative, positive and beater bodies, or by using a sheath heater as the heater.

Example 6 As shown in FIG. 5, a cathode body of a plasma CVD processing apparatus having three stages of a sheath heater 4 having an anode body 3 and a protection tube as a cathode body 2 in a vacuum vessel 1 having a gas supply port b and a discharge port 1a. A workpiece 5 was placed on top and covered with TiN.

As a result, the processing capacity was improved to about 1.5 to 2 times that of the conventional structure having a cathode body, an anode body, and a heater independently. Furthermore, since the workpiece and the heater are in contact with each other, heat conduction is good and heating is easy to perform, so the thermal efficiency was improved by about 5 to 10%.

In this case as well, each heater is provided with independent temperature control means using the power source 6.

Further, as shown in FIG. 6, the processing capacity can also be improved by using the protective tube of the sheath 4 as the anode body 3. In this case, the heater was less contaminated than the one shown in FIG. 5, in which the protective tube of the sheath heater was used as a cathode.

In the apparatuses shown in FIGS. 5 and 6, as shown in Example 4, by providing a heater at the lowest stage, the temperature can be made more uniform.

Embodiment 7 As shown in FIG. 7, when forming a film by placing a workpiece 5 on a sheath heater 4 whose cathode body 2 is a protective tube as shown in FIG. The protective tube of the lower heater was not connected to the cathode power supply, but was connected to the ground 7 independently from other electrodes. When a film was formed using this plasma CVD processing apparatus, the bottom heater of the apparatus of the present invention was much less contaminated than the bottom heater of the plasma CVD processing apparatus shown in FIG. The number of treatments required to remove dirt has been reduced.

Further, the same effect was obtained even when the heater at the lowest stage of the plasma CVD processing apparatus shown in FIG. 7 was not connected to the ground and was made independent from other electrodes.

[Effects of the Invention] With the plasma CVD processing apparatus of the present invention, a uniform coating can be formed because the heating temperature of the workpiece and the gas flow are uniform. Furthermore, since the scraping body also serves as a heating means, the processing capacity becomes large.

[Brief explanation of the drawing]

1 to 7 are schematic diagrams showing embodiments of the plasma CVD processing apparatus of the present invention. FIG. 8 is a schematic diagram showing a conventional plasma CVD processing apparatus. 1...--Vacuum container 1a...Gas exhaust port 1
b...Gas supply port 2...Cathode body 3
... Anode body 4 ... Heater 5 ...
...Workpiece material 6...Power supply 7...
・Earth

Claims (10)

[Claims] (1) A plasma CVD processing apparatus characterized in that a cathode body and/or anode body and a heating means are arranged in plural stages at intervals in a vacuum container equipped with a gas supply port and an exhaust port. (2) The plasma CVD processing apparatus according to claim 1, wherein at least one stage of the anode body, the cathode body, and the heating means is provided with a gas communication port. (3) The plasma CVD processing apparatus according to claim 1, characterized in that a heating means is provided at the uppermost stage and/or the lowermost stage. (4) The plasma C according to claim 1, wherein the heating means is either molybdenum or tungsten.
VD processing equipment. (5) The plasma CVD processing apparatus according to claim 1, wherein the heating means is a sheath heater. (6) The plasma C according to claim 1, wherein each heating means is equipped with a temperature control device for controlling the heating temperature.
VD processing equipment. (7) A vacuum container equipped with a gas supply port and an exhaust port has a plurality of cathode bodies and anode bodies disposed at intervals, and the cathode body and/or the anode body also serves as heating means. Plasma CVD processing equipment. (8) The plasma CVD processing apparatus according to claim 7, wherein the heating means is a sheath heater. (9) The plasma CVD processing apparatus according to claim 7, wherein either the anode body or the cathode body is provided with a communication port through which gas passes. (10) The plasma C according to claim 7, wherein each heating means is equipped with a temperature control device for controlling the heating temperature.
VD processing equipment.