JPH0321087B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a thin film forming apparatus and a thin film forming method using the same. More specifically, the present invention relates to a technique for forming a thin film by chemical vapor deposition (CVD) or physical vapor deposition (PVD), which utilizes discharge and light irradiation simultaneously.

Prior Art Various CVD and PVD technologies using light or discharge have been known. however,
A drawback of conventional CVD and PVD devices that use light is that the light introduction window used to introduce light into the vacuum container becomes dirty during thin film formation, resulting in a decrease in light transmittance. To solve this problem, methods are used to prevent thin film materials from adhering to the direct light introduction window by installing a mirror inside the decompression chamber, but in this case, the surface of the mirror is contaminated with the thin film material and reflects light. This is not a fundamental solution because the rate is poor.

Problems to be Solved by the Invention The present invention improves the continuous operating time of the device by preventing contamination of the light introduction window that conventionally occurs during thin film formation in CVD or PVD devices that use light. The aim is to improve the operating rate of

Means for Solving the Problems In view of the drawbacks of the conventional devices described above, the present invention provides a discharge electrode consisting of a grid-like electrode or a counter electrode near the light introduction window. The present invention provides a method for preventing contamination of a light introduction window by ionizing fine particles of thin film material by glow discharge and trapping them by an electric field.

Effect Generally, when forming a thin film using the PVD method or CVD method, a method is used in which a reaction gas is introduced into a vacuum container, evaporated fine particles are generated, and these are reacted or deposited on the substrate surface. However, these reactive gases and evaporated fine particles naturally approach the light introduction window. Therefore, by installing a glow discharge electrode to which a voltage is applied near the light introduction window in advance, the approaching reactive gas and fine particles are ionized by glow discharge and trapped in the electrode, thereby preventing contamination of the light introduction window. It is possible to prevent this and ensure the optical path of the light introduction window.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. For example, when performing laser beam evaporation, as shown in FIG. container 6
an exhaust device 7 for exhausting the gas inside, and an external light source 8
In the thin film forming apparatus having the discharge power source 9, after exhausting the gas in the reduced pressure container in advance,
A target 12 of thin film material is irradiated and evaporated using a light beam 10 (for example, light from a CO ₂ laser, a YAG laser, a ruby laser, or another infrared lamp, etc., condensed using a lens 11) to form a substrate 13.
When forming a thin film on the top, in advance, the light introduction window 1 is
By applying a direct current or alternating current (including high frequency current) voltage to the nearby discharge electrode 3, the approaching evaporated fine particles of the thin film material are ionized by discharge, and by keeping the potential of the discharge electrode 3 positive, light is emitted. By repelling ions approaching the introduction window and trapping them in a negatively charged part (for example, the substrate), contamination of the light introduction window 1 by evaporated matter can be significantly reduced. 16 is a mirror.

Note that at this time, if a small amount of inert gas such as Ar or He is introduced, the discharge can be easily stabilized. It goes without saying that if vapor deposition is performed while introducing a reactive gas, a vapor deposited film accompanied by a plasma reaction can be obtained. In addition, in the case of Figure 1, since the electrodes are installed on the optical path, the electrodes must be shaped like a grid in order for the light beam to pass through.
In the type shown in FIG. 2, the discharge electrodes 14 and 15 face each other and do not obstruct the optical path, so they do not need to be grid-shaped.

Furthermore, the above-mentioned principle is not only applicable during laser beam deposition. For example, the effects of the present invention are fully exhibited even in optical CVD as shown in FIG.

That is, after evacuating the gas in the depressurized container 21 in advance, while introducing the reactive gas through the gas inlet 22 and applying a voltage to the discharge electrode 23 to cause discharge, the light collected through the light introduction window 24 is It is also possible to deposit a thin film by introducing 25 and causing a gas phase chemical reaction on the surface of the substrate 26 that is irradiated with light.

In this case as well, the ionized gas can be prevented from approaching the light introduction window 24 by keeping the potential of the discharge electrode 23 at a positive potential. Further, by keeping the potential of the substrate holder 27 or the substrate at the lowest level in the vacuum container, it is possible to efficiently collect the ionized thin film material on the substrate surface. In FIG. 3, 28 is an exhaust port, 29 is a condensing lens, 30 is a light source, and 31 is a discharge power source.

Effects of the Invention As described above, by using the thin film forming apparatus of the present invention and the thin film forming method using the same,
When forming thin films using light beam evaporation or optical CVD, contamination of the light introduction window can be significantly reduced.
In addition to improving the continuous operating time of the device or improving the operating rate of the device, it is also possible to form a good thin film without complicating the device structure by devising a discharge electrode. It is very effective.

[Brief explanation of the drawing]

1 and 2 are diagrams for explaining a thin film forming apparatus and a thin film forming method using the same in an embodiment of the present invention. FIG. 1 is an example using grid electrodes, and FIG. An example using electrodes is shown, and FIG. 3 is a diagram for explaining still another embodiment of the present invention. 1, 24... Light introduction window, 2, 27... Substrate holding part,
3, 14, 15, 23...discharge electrode, 5, 28...
Exhaust port, 6, 21...reduced pressure container, 7...exhaust device,
8, 30...Light source, 9, 31...Discharge power source.

Claims (1)

[Claims] 1. A reduced pressure container equipped with a light introduction window, a substrate holder, a discharge electrode, a gas inlet, and an exhaust port, an exhaust device for exhausting gas in this reduced pressure container, an external light source, and a discharge A part of the discharge electrode is a grid-shaped electrode installed near the light-introducing window and parallel to the light-introducing window, and the potential of the grid-shaped electrode is adjusted to the potential of the substrate holding part. Using a thin film forming apparatus with a potential higher than that, the gas in the reduced pressure container is evacuated in advance, and light is introduced through the light introduction window while discharging at the discharge electrode to irradiate and heat the thin film raw material to evaporate it, or A method for manufacturing a thin film, characterized in that a thin film is formed on the surface of a substrate placed in the substrate holder by causing a gas phase chemical reaction with light, and the ions forming the thin film are repelled by the grid electrode. 2. It has a reduced pressure container equipped with a light introduction window, a substrate holder, a discharge electrode, a gas inlet, and an exhaust port, an exhaust device for exhausting the gas in the reduced pressure container, an external light source, and a power source for discharge, Using a thin film forming apparatus in which the discharge electrode is a counter electrode installed near the light introduction window, after previously exhausting the gas in the reduced pressure container, the discharge electrode is used to discharge gas from the light introduction window while discharging at the electrode. Light is introduced to irradiate and heat the thin film raw material to evaporate it, or the light causes a gas phase chemical reaction to form a thin film on the surface of the substrate placed in the substrate holder, and the thin film forming ions are removed by the discharge electrode. A thin film manufacturing method characterized by repelling.