JPS5853066B2 - Hot cathode discharge type ion plating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hot cathode discharge type ion blating device, which is suitable for mass production by providing a discharge anode on the opposite side of the substrate from the hot cathode. The purpose is to provide a rating device and method.

Conventionally, ion blating, particularly reactive ion blating, is a process in which an activated gas introduced into an activation atmosphere (gas discharge plasma) reacts with an evaporated substance or with each other to form a reaction product film on a substrate to which an electric field is applied. Many methods have been devised, including the matrix method, multi-cathode method, high-frequency excitation method, and hot cathode discharge method, depending on the method of forming a gas discharge plasma in an activating atmosphere and the method of applying an electric field to the substrate. ing.

In general, in conventional ion blating equipment, a gas discharge plasma, which is an activation atmosphere, is formed mainly between an evaporation source and a substrate, and the evaporated particles and introduced gas are excited or activated and reacted in the gas discharge plasma, and an electric field is generated. The main focus is on the process of obtaining a compound film that undergoes the reaction on a substrate to which a Met.

In recent years, attempts have been made to apply the above-mentioned ion blating as a surface treatment method in a pollution-free process, especially reactive ion brating, which produces a hard, corrosion-resistant film, to decorative exterior parts, corrosion-resistant and wear-resistant parts, etc. There has been a need for a mass-produced ion blating device and method that can process large quantities.

However, the conventional ion blating equipment has low processing capacity for mass production due to its small film deposition rate and small effective processing area, and is therefore not suitable for mass production. However, it was necessary to improve the intensity and distribution of gas discharge plasma.

Among conventional ion blating devices, the hot cathode discharge type ion blating device uses a gas discharge plasma generated by a large amount of thermoelectrons emitted from the hot cathode to the opposite anode under a low vacuum of 10" Torr or less. In particular, the plasma with glow represented by the Lang near mode has a high intensity and is relatively uniformly distributed over a wide area from the hot cathode to the anode. By doing so, it was possible to set up a method suitable for mass production.

However, conventional hot cathode discharge type ion blating equipment, like other types of general ion blating equipment, emphasizes the process of forming the main gas discharge plasma between the substrate and the evaporation source as described above. Therefore, depending on this type of process, it is difficult to form gas discharge plasma with excellent intensity and distribution on a mass-produced substrate having a large area.

The present invention is based on the phenomenon that in a mass-produced reactive ion blating process, when the main gas discharge plasma is formed around the substrate, the film formation rate and effective processing area in the process increase. We have developed a hot cathode discharge type ion blating device that is suitable for mass production and forms gas discharge plasma with excellent intensity and distribution around the substrate by installing opposing anodes on the opposite side of the substrate. It is something.

The present invention will be described in detail below with reference to figures and examples.

As shown in FIGS. 1 and 2, the apparatus of the present invention includes a vacuum chamber 1, a vacuum exhaust system P for evacuating the vacuum chamber through a vacuum exhaust pipe 2, and a gas introduction pipe for introducing carrier gas and active gas. 3 and a gas introduction system G, an evaporation source 4 and a power supply B for the evaporation source to operate the evaporation source, a substrate 6 consisting of a frame-shaped jig on which a large number of objects to be processed are mounted, and a substrate for applying an electric field to the substrate. A power source K, a hot cathode 5, and a power source for the hot cathode that operates the hot cathode (in the device shown in Fig. 2, the hot cathode 5 that also serves as an evaporation source)
(only), an anode 7, and a discharge power source A capable of applying a positive potential to the anode with respect to the hot cathode.

In the device mechanism of the present invention, the anode has a slightly larger external shape than the substrate shape, and has a structure such as a plate, a lattice bar, or a mesh shape.

Although not described in the device example of the present invention, a shutter,
It naturally includes mechanisms essential to general vacuum evaporation equipment, such as a vacuum degree measuring element.

The apparatus shown in FIG. 1 according to the present invention is configured to exhaust a vacuum chamber 1 through an evacuation pipe 2 to a temperature below I x 10" Torr by a vacuum evacuation system P, and then introduce at least one type of gas through a gas introduction pipe 3 through a gas introduction system G. Then, the vacuum chamber 1 is maintained in a vacuum range of LX 10'To?''r, the hot cathode 5 and the hot cathode power source are activated to cause thermionic emission, and then the anode 1 is powered by the discharge power source A. A potential of +30 V to +500 V is applied to form a gas discharge plasma that becomes a hot cathode discharge in the vacuum chamber 1, and a potential of -10 V to -IKV is applied to the substrate 6 by the substrate power supply K to cause the evaporation source 4 and the It is operated by activating the evaporation source power source B to heat and evaporate the material to be evaporated 5.

In this device according to the present invention, the hot cathode discharge current is increased or decreased by increasing or decreasing the output of the discharge power source A, and the substrate current density is changed by mutually changing the outputs of the substrate power source K and the discharge power source A. can be done.

The apparatus shown in FIG. 2 according to the present invention is a system in which the object to be evaporated is operated as a hot cathode without requiring a special hot cathode. Therefore, the anode power source A is used to connect the hot cathode, that is, the object to be evaporated 5 to the anode 7. The object to be evaporated 5 is heated by applying a positive potential.
It operates in substantially the same manner as in FIG. 1 above, except that a gas discharge plasma is formed by thermionic electrons emitted from the plasma.

In the apparatus according to the present invention, the discharge current changes depending on the heating temperature of the object to be evaporated and the output of the discharge power source A, and the substrate current density changes corresponding to the discharge current and the substrate potential.

Example 1 The apparatus shown in FIG. 1 was operated according to the method described above, nitrogen gas was used as the introduced gas, and the degree of vacuum was 5×10'To? '? ", Ti was evaporated at a film formation rate of 1 μ74 min using an electron beam heating method under the conditions of an anode potential of +80 V and a substrate potential of -500 V, and reactive ion blating was performed. As a result, a discharge current of 13 A and a substrate current density of 1. 2 mA/cr7f was confirmed, and a yellow titanium titanium film with an almost uniform color tone was obtained on a circular substrate having a diameter approximately 2.0 times the substrate distance from the nitride film. The atomic ratio i was 0.65 at the center of the substrate and 0.62 at the outer periphery of the substrate.

Furthermore, when reactive ion blating was performed using the apparatus shown in Figure 3 under the same conditions, the discharge current was 14 A and the substrate current density was 0.
．． 8 mA/crA was confirmed, and the center was yellow on the substrate having a diameter approximately 2.0 times the distance of the substrate from the object to be evaporated.
A titanium nitride film having a reddish-yellow outer circumference was obtained, and the - atomic Ti ratio of the titanium film was 0.58 at the center of the substrate and 0.47 on the outer periphery of the substrate.

Example 2 The apparatus shown in Figure 2 was operated according to the method described above, nitrogen gas was used as the introduced gas, the vacuum was I x 10-2 Torr, the anode potential was +200 V, and the substrate potential was -30 V using a resistance heating type tungsten port. When reactive ion blating was performed by evaporating vanadium at a rate of 0.5A7w1n, a discharge current of 50A and a substrate current density of 10.5mA/crd were confirmed, which was approximately 2.0 times the distance of the substrate from the object to be evaporated. A pink-colored vanadium nitride film with an almost color tone was obtained on a circular substrate having a diameter of Ta.

Furthermore, when reactive ion blating was performed using the apparatus shown in FIG. 3 under the same conditions and applying the same discharge current, a substrate current density of 5.8 mA/ca was confirmed, and the substrate current density from the evaporator to the substrate was approximately 2.5 mA/ca. A vanadium titanium with a pale pink color at the center and white at the outer periphery was obtained on a circular substrate having a diameter of 0 times, and the - atomic ratio of the titanium film was 0.4 at the center of the substrate.
8. It was 0.35 at the outer periphery of the substrate.

In the mass-produced reactive ion blating process, the present invention moves the main gas discharge plasma formation center from between the substrate and the evaporation source to the vicinity of the substrate, thereby increasing the film formation rate and effective processing area of the process. This is based on the phenomenon that, as shown in Examples 1 and 2, an apparatus in which the anode of the present invention is disposed through a substrate can increase the reaction rate corresponding to the film formation rate compared to the conventional apparatus. The rate of progress is increased, and the difference between the effective treatment area and the rate of progress of the corresponding reaction depending on the substrate position is reduced.

Generally, in a hot cathode discharge, the maximum thermionic electron transfer occurs between the hot cathode and the anode facing the hot cathode, and the gas discharge plasma formed as a result has a center of formation between the electrodes, and also depends on the shape of the anode, etc. It is said that the shape and distribution of the plasma also change, and in the device of the present invention, by placing the substrate between the electrodes and aligning the anode approximately to the shape of the substrate,
It is possible to form gas discharge plasma with excellent intensity and distribution in close proximity to the substrate, and due to the above-mentioned phenomenon, a hot cathode discharge type ion blating apparatus is provided which has a large film formation rate and a large effective processing area.

Although an electron beam heating method and a resistance heating method were employed in the embodiment, all general evaporation methods used in vacuum evaporation equipment can be applied to the apparatus of the present invention.

In the examples, nitrides of Ti and V were mainly formed using nitrogen gas, but the device of the present invention, like other general ion blating devices, uses active gases such as oxygen, acetylene, argon, and helium. Using one or more inert gases such as Al□, silicon, chromium, and other metals and alloys, as well as non-metallic nitrides, oxides, carbides, borides,
A film of compounds such as phosphides and silicides can be formed.

In Example 2, a method was adopted in which the material to be evaporated using vanadium was operated as a hot cathode, but from the principle of this method, the amount of electron emission according to the Richardson-Dushman equation is 1×10'A/cf1. All of the above substances can be applied to the present device of the present invention.

In the example, the degree of vacuum was 5X10' Torr and IXIO'' Torr, respectively, but the device of the present invention has a degree of vacuum of about 1
' It can be applied in low vacuum below Torr.

The vacuum range is preferably up to 5×10 ” Torr, which is the upper limit of the characteristics of the deposited film.

The uninvented device basically applies the general theory of hot cathode and ion blating, and therefore the left current can stably form a gas left plasma from 0.5A to the maximum current of the set power supply. Applicable, but generally 1-100
The current value range of A is practical considering the price of the power supply and the simplification of ancillary equipment, and the substrate current density ranges from 0.05 mA/ci to 0.05 mA/ci, which can provide an activation atmosphere for mass production, and increases substrate temperature and ion sputtering. A suitable setting is 200 mA/crA so that etching by 1 non-etching does not become excessive.

The present invention increases the film formation speed and effective treatment area by placing the center of the gas discharge plasma near the substrate, which has traditionally been inferior in mass production processing capacity and manufacturing cost compared to other surface treatment techniques. .

This provides the possibility of applying the surface treatment method of ion blating as a treatment method comparable to conventional methods, and provides a new field of surface treatment methods that are non-polluting and have excellent film quality.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a multi-hot cathode discharge type ion plating device according to the present invention, FIG. 2 is a block diagram of a hot cathode discharge type ion plating device operated as a hot cathode according to the present invention, and FIG. The figure shows the configuration of a conventional hot cathode discharge type ion blating device. DESCRIPTION OF SYMBOLS 1... Vacuum chamber, 2... Exhaust pipe, 3... Gas introduction pipe, 4... Evaporation source, 5... Hot cathode, 5... Hot cathode (object to be evaporated), 6... ... Substrate, 7... Anode, 8...
Reflector plate, A... power source for discharge, B... power source for evaporation source,
K: power supply for the substrate, P: vacuum evacuation system, G: gas introduction system, F: power supply for hot cathode.

Claims (1)

[Scope of Claims] 1. In a vacuum chamber at ground potential, an evaporation source, a substrate to which a negative potential is applied with respect to the ground potential, a hot cathode at ground potential, and a positive potential to which a positive potential is applied. In the ion blating apparatus, the substrate comprises a frame-shaped jig on which a large number of objects to be processed are mounted, and the anode is arranged behind the substrate with respect to the evaporation source. A hot cathode discharge type ion brating device characterized by: 2. The hot cathode discharge type ion blating device according to claim 1, wherein a plurality of hot cathodes are arranged between the evaporation source and the substrate. 3. The hot cathode discharge type ion blating device according to claim 1, wherein the evaporation material placed on the evaporation source is at ground potential and also serves as a hot cathode.