JPH0676657B2 - Sputtering device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a sputtering apparatus for forming a thin film in a vacuum, and particularly for use in a load lock type continuous sputtering apparatus in which a thin film forming chamber is always kept in vacuum. The effect is remarkable.

(Prior art) In a sputtering device, sputtered atoms flying from the target adhere to the walls and jigs inside the thin film formation chamber and peel off to cause abnormal discharge on the target or foreign matter on the substrate. It causes the problem of doing.

If the batch type sputtering device opens the thin film forming chamber to the atmosphere every time the substrate is replaced, the state of film adhesion to the inner wall surface and jigs and the degree of film peeling are checked every time the substrate is opened, and the film strip is removed. It is possible to prevent abnormal discharge on the target or foreign matter from adhering to the substrate in advance because necessary measures such as removal of impurities can be taken.

However, in the load lock type continuous apparatus, since the thin film forming chamber is always kept in vacuum, it is not possible to inspect the inside or remove deposits. Therefore, when the device is operated for a long period of time, the film continues to adhere inside the thin film forming chamber and eventually peels off, causing abnormal discharge on the target and foreign matter on the substrate, which eventually becomes It also develops into situations such as short-circuiting between grounds and stop of discharge.

In order to prevent the above-mentioned accidents in continuous equipment, a method called side sputtering is used. This is to prevent the occurrence of defects by holding the target and the substrate vertically so that even if the film peels off from the wall surface or jig in the thin film formation chamber, it will fall without contacting the surface of the target and the substrate. is there.

According to this method, the above-mentioned accident can be prevented considerably, but this alone cannot prevent the film piece from peeling off from the wall surface or the jig. This method is effective when sputtering a material that has strong adhesion and is relatively hard to peel off, such as aluminum, but like a film of molybdenum, tungsten, etc., the internal stress in the film is large and it tends to warp With materials that are extremely susceptible to peeling when attached to a jig or jig, this method alone is not sufficient, and accidents such as abnormal discharge and discharge stop are likely to occur.

It takes a lot of time and effort to remove debris and dust when these film pieces are peeled off and scattered in the vacuum chamber, and they cause various problems such as sticking to the sealing surface such as the O-ring and causing a leak. There is.

FIG. 2 is a schematic configuration diagram of a conventional thin film forming chamber (for example, Japanese Patent Laid-Open No. 60-26659 “Sputtering Device”) devised to solve this problem.

The deposition preventive plate 5 around which the heater winding 18 is wound is provided so as to surround the target 4 and the cathode 3, and the thin film passes through the inner surface of the deposition preventive plate 5 and the opening of the window 9 to cover the substrate 7 and its periphery. It is designed to be formed only in a relatively narrow area. During the sputtering, the heater 18 is energized to heat the deposition-inhibiting plate 5, and the thin film is strongly adhered to the deposition-inhibiting plate to prevent peeling. Do not heat at the end of sputtering.

Further, a partition plate 10 is attached in the immediate vicinity of the target 4, and a pocket portion 11 for storage, which is partitioned by this partition plate, is provided inside the deposition-inhibitory plate, so that the fragments separated from the inner surface of the deposition-inhibitory plate 5 are provided. Are stored here.

As a result of the above measures, the peeling of the film pieces is reduced, the situation in which the fragments touch the target and cause an abnormal discharge to stop the discharge, and the scattering of the fragments in the vacuum chamber is also reduced.

The conventional deposition preventive plate 5 is made of the same metal as the target or stainless steel.

However, even with this conventional structure, the temperature of the deposition-inhibition plate changes greatly during spattering and non-sputtering, and the repetitions are frequent, so that stress due to temperature change is added to the internal stress hidden in the adhered film. However, there is still a drawback that the film pieces are easily peeled off. If a large amount of debris accumulates in the retaining portion 11 of the deposition preventive plate 5, short-circuiting with the target is likely to occur, which may cause an accident such as abnormal discharge or discharge stoppage.

(Object of the Invention) It is an object of the present invention to solve the above problems and provide a sputtering apparatus in which an adhered film hardly peels off.

(Means for Solving Problems) In the present invention, in order to achieve the above-mentioned object, an adhesion-preventing plate is provided along a side surface of the target which does not face the substrate, and the adhesion-preventing plate is projected from a side edge of the target. Has a taper portion that opens toward the bottom and a taper portion that faces the lower wall of the thin film forming chamber.There is a space between the substrate and the space below the space, and the space is separated from each surface by sputtering. A reservoir for accommodating the thin film is provided, and a heating device for heating each surface is attached to each surface on which the thin film is attached by sputtering. The heating device applies a power to the heating device and a heating power source for applying the electric power to the heating device. Connect with a switch that switches power,
The switch is turned off during sputtering and turned on during non-sputtering.

(Function) Each surface to which the thin film is attached naturally has a high temperature during the sputtering, but the temperature decreases during the non-sputtering. Although the temperature drops during non-sputtering, the switch turns on and power is applied to the heating device from the heating power supply. Therefore, the heating device heats each surface on which the thin film adheres, the temperature of the adhesion surface is prevented from lowering, and the temperature of the adhesion surface is kept at a high temperature. By connecting a switch that turns off during sputtering and turns on during non-sputtering and a heating power supply to the heating device, it is possible to eliminate temperature changes on the surface during sputtering and during non-sputtering. This prevents the stress from being generated and prevents the thin film from peeling due to warpage.

(Example) Next, the Example of this invention is described in detail using drawing.

FIG. 1 is a schematic configuration diagram of a thin film forming chamber according to an embodiment of the present invention. Illustrations of the exhaust system, the gas introduction system, the load lock chamber, and the transfer system are omitted.

In the figure, reference numeral 1 is a thin film forming chamber, and when the chamber is evacuated to a vacuum and a voltage is applied between the cathode 3 and the ground by using a power source 2, the target 4 mounted on the cathode and the ground potential are protected. Plasma is generated in the space surrounded by the plate 5 and the substrate holder 6, and the target is bombarded with cations to perform sputtering, so that a thin film is formed on the substrate 7 facing the target. In this example, the substrate is stationary during deposition.

The feature is the heaters 14 and 8 provided to heat the surfaces to which the thin film is attached during sputtering, such as the barrier surface 13 and the inner surface of the deposition-inhibitory plate 5.

The deposition preventive plate 5 is provided along the side surface of the target 4 that does not face the substrate 7, has a taper portion 5A that extends from the side edge of the target 4 and opens toward the substrate 4, and is made of aluminum. The surface to which the film is attached is sandblasted with fine particles of alumina. The heater 8 is built in just inside the surface.

The surface of the barrier surface 13 is also made of the same material and processed as above,
The heater 14 is in close contact with the back surface.

During the sputtering, a film adheres to the barrier surface 13 and the surface of the deposition preventive plate 5, and the temperature becomes high. The temperature starts to drop at the same time as the sputtering ends.At this time, the heaters 13 and 8 are turned on, or high power more than during the sputtering is applied to prevent the temperature drop (heater power supply and switch are not shown). ing). That is, as described above, the temperature change is suppressed to prevent the stress from being generated in the attached film, and the peeling is prevented.

Since each surface is made of aluminum, the adhesion of the thin film is strong and peeling is less likely to occur. Further, since the adhesive force of the thin film is enhanced by the sharp unevenness of the alumina-blasted surface, the peeling is remarkably reduced.

In the unlikely event that the adhered film is peeled off, the adhesion prevention plate 5 has a taper portion 5A that extends from the side edge of the target and opens toward the substrate.
Since the film is formed, the film piece slipped off from the surface of the taper portion 5A is not in the adhesion-preventing plate 5 near the target 4 as in the conventional case, but in the space between the adhesion-preventing plate 5 and the substrate 7. Department
It accumulates in a reservoir 12 provided below 20. This will prevent the film piece from touching the target and causing inconvenience.

From the above, it has been confirmed by experiments that the continuous sputtering apparatus can continuously form a thin film for a long time even when sputtering a metal such as molybdenum, tungsten, or titanium-tungsten which is easily peeled off.

It should be noted that the present invention can of course be implemented with the same configuration as shown in FIG. However, in this case, the heater 18 is contrary to the conventional one,
Heating is performed by turning on during non-sputtering, or by applying high power more than during sputtering.

In addition, as the material of each surface, aluminum and aluminum alloys showed good results. And the sand grains used for sandblasting were fine particles of alumina with sharp corners, which gave good results.

(Advantages of the Invention) Since the present invention has the configuration and the operation as described above, even in the case of sputtering of a metal that easily peels off, the adhesion film hardly peels off from the surrounding adhesion surface, and the continuous type A thin film can be continuously formed by incorporating it in a sputtering device for a long time.

[Brief description of drawings]

 FIG. 1 is a schematic configuration diagram of a thin film forming chamber of the present invention. FIG. 2 is a similar view to the conventional one. 1 ... Thin film forming chamber, 2 ... Power supply, 3 ... Cathode, 4 ... Target, 5 ... Bonding plate, 6 ... Substrate holder, 7 ... Substrate, 8, 14, 18 ... Heater, 9 ... Window, 10 ... Partition plate, 11 ... Reservoir side, 12 ... Reservoir, 13 ... Barrier surface.

Claims (1)

[Claims] 1. A sputtering method in which the flat surfaces of a substrate and a target placed in a thin film forming chamber evacuated to a vacuum are held vertically, and the thin film is formed in a state where the substrate and the target are in a static one-to-one relationship with each other. In the apparatus, an adhesion-preventing plate is provided along a side surface of the target that does not face the substrate, the adhesion-preventing plate has a taper portion that extends from a side end of the target and opens toward the substrate, and There is a space between the substrate and the adhesion-preventing plate having a taper portion toward the lower wall, and a reservoir for accommodating the thin film peeled from each surface by sputtering is provided below the space, and the thin film A heating device for heating each surface is attached to each surface to be attached, and a heating power source for applying electric power to the heating device and a switch for switching electric power applied to the heating device are attached to the heating device. Connecting the switch, a sputtering apparatus, characterized in that during sputtering the switch is in a non-sputtering during the on and off.