JPS6223978A - Sputtering device - Google Patents

Abstract

PURPOSE:To prevent the dew condensation on the rear surface of a back plate and to stabilize film quality by reducing the pressure in the atmosphere on the surface of the back plate in contact with the atm. thereby decreasing the dew point thereof. CONSTITUTION:A target 1 and a substrate 2 are disposed to face each other in a vacuum vessel 3. Electric power is impressed between the target 1 and the substrate 2 to electrolytically dissociate the atmospheric gas. The material constituting the target 1 is driven out by the impact of the cations generated in this stage. Both the substrate 2 and the vessel 3 are grounded so that the electric power can be impressed to the back plate 4 attached with the target 1 on one side by insulating the plate by the vessel 3 in order to deposit the film of the above-mentioned material onto the surface of the substrate 2. A reduced pressure vessel 5 is provided to cover the other surface of the plate 4. Provision is so made that the pressure in the vessel 5 can be reduced.

Description

[Detailed Description of the Invention] [Summary] A back plate to which a target is attached may condense on the surface in contact with the atmosphere due to cooling water, resulting in poor insulation. In order to prevent this, we propose a sputtering apparatus that reduces the pressure of the atmosphere on that surface to lower the dew point.

[Industrial application field]

The present invention relates to a sputtering apparatus having an improved cooling method for a cougette and having a structure suitable for increasing size and power.

In recent years, as semiconductor wafers and photomasks for manufacturing large-scale integrated circuits (LSI) have become larger, the targets of the Suba-Tsuta equipment have become larger and the power supply has also increased, making cooling the target more important.

If water with a temperature below the dew point of the room where the equipment is installed is used as cooling water, dew will condense on the surface of the back plate that is in contact with the atmosphere, resulting in poor insulation.

Therefore, since the cooling water temperature cannot be lowered much, the target cooling effect is not sufficient, and countermeasures are desired.

[Conventional technology]

FIG. 2 is a sectional view schematically showing a conventional sputtering apparatus.

In the figure, 1 is a target, 2 is a substrate (semiconductor wafer, mask, etc.), and 3 is a vacuum container.

The vacuum container 3 is provided with a sputtering gas inlet 31 and an exhaust port 32.

The target 1 is attached to the back plate 4 with a solder made of a low melting point alloy such as indium (In) or tin (Sn).

- The back plate 4 has a cooling chamber 20 with a water canopy structure through which cooling water can circulate, and is fixed to the vacuum container 3 via an insulating plate 6 made of Teflon or the like. At this time, the vacuum container 3 is kept airtight by the vacuum packing 8.9.

A sputtering power source 9 is connected between the bank plate 4 and the ground potential, and the substrate 2 and the vacuum container 3 are grounded.

Magnets 10 and 11 are arranged in large numbers radially on the back surface of the target 1, and the magnetic field generated thereby serves to increase the electron density on the surface of the target 1 and improve sputtering efficiency.

In the above structure, since the surface of the water-cooled back plate 4 is exposed to the atmosphere, the temperature of the cooling water cannot be lowered very much because dew condenses and causes insulation failure.

[Problem that the invention seeks to solve]

In a sputtering apparatus having a conventional structure, dew condensation may occur on the surface of the hack plate to which the target is attached, which is in contact with the atmosphere, resulting in poor insulation, which may reduce sputtering efficiency.

[Means for solving problems]

The above problem can be solved by arranging the target (1) and the substrate (2) in a vacuum container (3) so as to face each other.
Electric power is applied between 11 and the substrate (2) to ionize the atmospheric gas, and the impact of the terrestrial cations knocks out the substance constituting the target (1), and the coating of the substance is removed from the substrate (2). ), the substrate (2) is grounded together with the vacuum vessel (3), and a bank plate (4) with a Targetera +- (11 attached to one side) is attached to the vacuum vessel (3). A vacuum container (5) is provided covering the other side of the bank play H4 (cooling chamber (20)) so that electric power can be applied with better insulation, and the pressure inside the vacuum container (5) can be reduced. This is achieved by a sputtering apparatus according to the present invention having a structure as follows.

[Effect]

Depressurizes the atmosphere on the surface of the bank plate that is in contact with the atmosphere to lower the dew point and prevent condensation.

Now, the relationship between saturated water vapor pressure and temperature is as follows.

Temperature ('C) Saturated water vapor pressure (Torr) 20
0.95 04.6 20 17.5 50 92,5 100 760.0 150 3570.7 As can be seen from this table, when the pressure is reduced to about 5 Torr, even if the temperature of the cooling water is lowered to nearly 0°C, No condensation.

〔Example〕

FIG. 1 is a sectional view schematically showing a sputtering apparatus according to the present invention.

In the figure, ] is a target, 2 is a substrate, 3 is a vacuum container, 4 is a bank plate, 6 is an insulating plate, 7.8 is a vacuum packing, 9 is a power supply, 10.11 is a magnet, 20 is a cooling chamber,
The above is the same as the conventional example shown in FIG.

The decompression vessel 5, which is a feature of the present invention, is provided to cover the surface of the bank plate 4 that is exposed to the atmosphere, and is approximately 100 m wide from the exhaust port 51.
It is exhausted to about Torr.

In addition, an insulating bushing 5 is installed in the cooling water passage of the back plate 4.
2.53 is inserted to maintain the insulation of the bank plate 4.

In the above structure, the cooling water temperature can be lowered to around 0° C., and the cooling effect of the target is improved.

〔Effect of the invention〕

As described above in detail, according to the present invention, dew condensation on the back surface of the bank plate to which the target is attached can be prevented.

Therefore, the cooling water temperature can be lowered, making it possible to sputter large substrates with high power and over a long period of time, which is useful for stabilizing film quality and preventing peeling between the target and the back plate.

[Brief explanation of the drawing]

FIG. 1 is a sectional view schematically showing a sputtering apparatus according to the present invention, and FIG. 2 is a sectional view schematically showing a sputtering apparatus according to a conventional example. In the figure, 1 is a target, 2 is a substrate (semiconductor substrate, mask substrate, etc.), 3 is a vacuum container, 4 is a bank plate, 5 is a vacuum container, 6 is an insulating plate, 7.8 is a vacuum packing, 9 is a power supply, 10. 11 is the magnet, 20 is the cooling room-t, IP Okaki Zoku ox to 'ヅj7 seasons (L Fig. 1 ↓''' Pa 8 Exhaust! L # Green sorrel, ivy, g' 2nd To ”

Claims (1)

[Claims] A vacuum container (3) in which a target (1) is disposed facing a substrate (2) for film formation, and a vacuum container (3) corresponding to the target (1) on the outside of the vacuum container (3). A sputtering apparatus comprising: a cooling chamber (20) connected to the vacuum chamber (20); and a reduced pressure chamber (5) provided on the opposite side of the vacuum chamber (3) and covering the cooling chamber (20). .