JPS589155B2 - Ion plating couch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ion plating apparatus for forming a film on a substrate in vacuum.

There are two methods for forming a film on a substrate in vacuum: vacuum evaporation and sputtering. When looking at the energy of the evaporation material, the former requires a heating temperature of 2300°K.
In this case, the voltage is about 0.2 eV, and the latter is about 10 eV on average, and the vapor deposited substance is mostly neutral atoms or molecules.

On the other hand, if a voltage is applied between the evaporation source of the evaporation material and the substrate on which the film is to be formed, the evaporation material is actively ionized, and then the evaporated material is accelerated and bombarded with the substrate. In 1963, the American M
This method was announced by ATTOX and is called the ion plating method.

There are two types of ion plating methods, one using direct current glow discharge and the other using high frequency glow discharge. Each has advantages and disadvantages and is used depending on the application, but the common point between them is that a film is formed on the substrate. In this case, the arrangement and potential of the vapor shield plate provided between the evaporation source of the evaporative substance and the substrate greatly influence the film formed on the substrate.

FIG. 1 shows a conventional ion plating apparatus using high frequency glow discharge.

In the figure, 1 is a vacuum container, and 2 is an evaporation source for an evaporative substance 3, which is, for example, a resistance heating type boat and is heated by a power source 4.

6 is a holding plate that holds the substrate 5 for film production;
Supported by

8 is a high frequency electrode provided between the boat 2 and the substrate 5;
9 is its high frequency power source.

10 is a DC power supply that applies a high voltage between the high frequency electrode 8 and the substrate 5, and either side thereof may be set to a negative potential;
In this embodiment, the substrate 6 side is set to a negative potential.

11 is a reaction gas introduction pipe, and 12 is its barrier pull leak valve.

Reference numeral 13 indicates an insulating bushing provided at a portion where the mast 7, the high-frequency electrode 8, and the support of the boat 2 pass through the base plate 14 of the vacuum vessel 10, and 15 indicates an exhaust port by a vacuum pump (not shown).

16 is a shielding plate provided between the high frequency electrode 8 and the boat 2;
It has a shutter window 17.

18 is a shutter plate for opening and closing the shutter window 17;
9 is its operating stick.

Boat 2 is grounded at one end. The shielding plate 16 and the shutter plate 18 may or may not be grounded, but in this embodiment, they are assumed to be at ground potential.

After exhausting the air in the vacuum container, when the high frequency power source 9 is operated at, for example, 13.56 MHz, a glow discharge is generated between the high frequency electrode 8 and the shutter plate 18.

Adjust the valve 12 from the reaction gas introduction pipe 11 depending on the purpose to introduce, for example, argon gas, and
When maintained at 0-3 to 10-4 Torr, the surface of the substrate 5 is cleaned by bombardment with argon ions.

Then, when the boat 2 is heated by the power source 4, the evaporated substance 3 is evaporated, so when the shutter plate 18 is opened, a part of the evaporated substance 3 is ionized by the high frequency electric field, and the DC power source 10
and is attracted to the substrate 5.

By the way, in this device, when the shutter 18 is opened, a sharp change occurs in the electric field within the container, and as a result, the state of glow discharge changes instantaneously.

Therefore, when trying to control the ratio of argon ions and evaporated substance ions to a predetermined value, even if the amount of argon ions is adjusted before the shutter plate is opened, the change in the electric field when the shutter plate is opened causes the argon ions to be The amount changes.

Since ions of the evaporated substance are included at the same time as the shutter plate is opened, it becomes difficult to set an appropriate ratio of argon ions and evaporated substance ions before starting work.

This poses a significant problem when the introduced gas is a reactive gas such as N2, O2, or C2H2 and a film is to be formed by chemical reaction with the evaporated substance.

For example, when attempting to produce a TiN film using N2 and Ti, a Ti2N3 film is initially generated, making it impossible to obtain pure TiN.

The present invention aims to provide an ion plating apparatus free from the above-mentioned problems, and includes an electrode that generates a glow discharge between an evaporation source that heats and evaporates the evaporated substance and a substrate that forms a film. A shielding plate is provided in the front surface of the substrate in close proximity to the substrate, and a shutter plate for opening and closing a shutter window of the shielding plate is held at approximately the same potential as the substrate.

The embodiment will be described below with reference to FIGS. 2 and 3.

In FIG. 2, numerals 1 to 15 are the same as those in FIG. 1, so their explanation will be omitted.

Reference numeral 20 denotes a shutter plate of the present invention, in which a shutter window 2 of a shielding plate 22 is supported by a stand 21 on the front side of a substrate 5.
Open and close 3.

This shutter plate 20 is connected to a column 24 and an arm 25 made of an insulating material.

Reference numeral 26 denotes an operating rod following the column 24. By rotating the operating rod 26, the shutter plate 20 moves horizontally as shown by the dotted line in FIG. 3, and the shutter window 23 is opened and closed.

Note that the shutter plate 20 and the shielding plate 22 are given the same potential as the substrate 5 through a conductive wire 27.

Since the apparatus of the present invention has the above configuration, the air in the vacuum container 1 is exhausted from the exhaust port 15 to 10-5 to 10-6T.
After creating a vacuum of about 5.0 or more Torr, the valve 12 is adjusted to introduce a reaction gas, for example, N2, into the vacuum vessel 1 from the introduction pipe 11 to make the vacuum about 5.times.10@-4 Torr.

Then, the high frequency power source 9 is switched on to generate a high frequency glow discharge between the high frequency electrode 8 and the boat 2.

Thereafter, the boat 2 is heated by a power source 4 to evaporate the evaporable substance 3, such as Ti.

At this time, adjust the high frequency power source 9, power source 4, and pulse 12 so that the conditions are optimal for TiN generation, and after the adjustment is completed, open the shutter window 23 to generate a TiN film on the substrate 5. .

In the conventional device (Fig. 1), since the shutter plate was located between the high-frequency electrode 8 and the boat 2, the state of the high-frequency glow discharge changes by opening and closing the shutter plate, and as mentioned above, the reaction gas and evaporation are mixed from the beginning. Although it has been difficult to set the substances in appropriate proportions, the device of the present invention (FIG. 2) places the shutter plate 20 in front of the substrate 5 in close proximity thereto.
In addition, since it is held at the same potential as this, opening and closing does not affect the high frequency electric field, and therefore a high quality film can be produced with the appropriate amount of reactant gas ions and evaporated substance ions set at the beginning. Can be done.

In addition, although the case of high-frequency glow discharge has been described above,
The present invention can also be applied to low frequency glow discharge and DC glow discharge.

[Brief explanation of the drawing]

Figure 1: Longitudinal cross-sectional view of a conventional ion plating device.
FIG. 2 is a longitudinal sectional view of an embodiment of the present invention; FIG. 3 is a plan view of the shutter plate of FIG. 2; Symbol 1... Vacuum container, 2... Light source (boat), 3...
... Evaporated substance, 4... Power source, 5... Substrate, 6...
Holding plate, 7... Mast, 8... High frequency electrode, 9...
・High frequency power supply, 10... DC power supply, 11... Reaction gas introduction pipe, 12... Pulve, 13... Pushing,
14... Base plate, 15... Exhaust port, 20... Shutter plate, 21... Stand, 22... Shielding plate, 23
...shutter window, 24...post, 25...arm, 26...operating rod, 27...conductor.

Claims (1)

[Claims] 1. In a vacuum container equipped with an electrode that generates a glow discharge between an evaporation source that heats and evaporates the evaporated substance and a substrate that generates a film, a shielding plate is provided on the front surface of the substrate in close proximity to the substrate. An ion plating apparatus characterized in that a shutter plate for opening and closing a shutter window of the plate is held at approximately the same potential as the substrate.