JPS6026659A - Sputtering device - Google Patents

Abstract

PURPOSE:To prevent sticking of a sputtering film to the inside of a thin film forming chamber by placing perpendicularly a substrate and target so as to face statically each other, providing the open end of a cylindrical plate for stick- preventive plate covering the target near the substrate and making said plate slightly larger than the substrate. CONSTITUTION:A substrate 6 is held by a holding jig 5 in a thin film forming chamber 1 and a target 3 is held by a cathode 2 in such a way as to face perpendicularly each other. The target 3 is enclosed with a cylindrical stick- preventive plate 7 and a window 10 provided there is made slightly larger than the substrate 6 and is positioned near the substrate 10. The plate 7 is constituted of the same material as the target 3 and a heater 11 is wound around the plate. The sticking of a sputtering film to the wall ans jig in the chamber 1 is prevented as far as possible. If a partition plate 8 is attached near the target 3, the sputtering film sticking to the inside of the plate 7 is contained into a groove 9 even if said film is tripped from the plate.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sputtering apparatus for forming a thin film in a vacuum, and in particular, it is mainly used for a load-lock type continuous type apparatus in which a thin film forming chamber is always kept under vacuum. This is the target.

As LSI manufacturing technology has progressed, continuous sputtering equipment using the cassette-to-cassette method has come to be used in the process of forming thin films on wafers. This continuous sputtering apparatus has a load-lock structure in which the thin film forming chamber is kept under vacuum and wafers are loaded and unloaded in a separate lock chamber. After the operator inserts the wafer cassette into the lock chamber, the wafers are automatically fed one by one from the lock chamber to the thin film forming chamber, and after forming the thin film, are automatically collected into the cassette. .

In such a continuous sputtering apparatus with a load-lock structure, the thin film forming chamber is always kept empty, so that the interior thereof cannot be inspected or confirmed at any time. On the other hand, in a sputtering apparatus, sputtered atoms flying from the target adhere to the walls and jigs inside the thin film forming chamber, causing phenomena such as peeling off and abnormal discharge on the target or adhesion of foreign matter to the substrate. In batch-type sputtering equipment, the thin film forming chamber is opened to the entire atmosphere every time the substrate is replaced.
Each time the board is replaced, check the adhesion or peeling of the film on the internal walls and jigs, and remove them to avoid problems such as foreign matter being released on the ditarget or adhering to the board. can be removed. But what about load-lock type continuous equipment? Because the tQI odor formation chamber is always kept under vacuum.

It is not possible to inspect the inside or remove the attached film. For this reason, if the equipment is operated for a long period of time.

The film continues to adhere to the inside of the thin film forming chamber, and eventually peels off, causing abnormal radiation on the target, addition of foreign matter to the substrate, and in extreme cases, short circuit between the target and ground, causing discharge. This may lead to a situation such as a shutdown. In this case, it is necessary to open the thin film forming chamber to the atmosphere and clean the inside, which reduces the effectiveness of the load-lock structure.

Recently, a method called side sputtering has been used to completely prevent the above-mentioned accidents in continuous type equipment. This holds the target and substrate vertically, and even if the film peels off from the wall or jig of the film formation chamber, it will fall without contacting the target or substrate surface, preventing abnormal discharge or the surface of the substrate. The purpose is to prevent foreign matter from adhering to the

Although this method can prevent a considerable number of the accidents mentioned above, this method cannot prevent peeling from the wall or jig itself. In fact, when performing stumbling on a material like gamma-luminium, which is soft and relatively difficult to peel off, this method can sufficiently prevent the above-mentioned accident. This method alone is insufficient for materials that peel off easily when attached to walls or jigs, and are still prone to accidents such as abnormal electrical discharges. The trouble of removing debris.

Alternatively, various problems such as leaks may occur due to adhesion to the seals such as J/D. The present invention performs sputtering of materials that are extremely susceptible to peeling, such as molybdenum, tungsten, and titanium-tungsten alloys. This is particularly effective in cases where an anti-adhesive plate is installed to prevent sputtered film from forming on the walls and jigs of the thin film forming chamber as much as possible. Prevents it from peeling off, even if it does come off.

Does it have a structure that does not cause problems such as adhesion to the wafer or scattering into the vacuum chamber? It is about providing.

The present invention will be explained in detail below using the drawings.

FIG. 1 is a simple example of the present invention, and shows the arrangement and structure of a target, a substrate, and an adhesion prevention plate in a thin J-shaped modeling chamber. In addition, there is one bow/pu for exhaust in this figure.

The illustrations of the pulp, gas liner, lock chamber, substrate conveyor tN, etc. that make up the load rotor structure are omitted. In the figure, l is a thin film forming chamber, and sputtering is performed on the nitrogen inside the chamber.Sputtering is performed by applying a voltage between the cathode 2 and the ground potential using a power source 4, and applying a voltage on the cathode. Plasma is generated in the space surrounding the mounted target 3, the earth potential adhesion prevention plate 7, and the substrate holder 5, and the target 3 is bombarded with positive ions.The substrate 6 is mounted on the holding jig 5. The substrate 6 and the target 3 are both erected perpendicularly to the horizontal plane.

During film formation, the substrate 6 remains stationary and does not move. The feature of this embodiment lies in the anti-J plate 7 provided so as to surround the cathode 2 and target 3. Is anti-adhesion plate 7 target 3? The thin film is formed only on the substrate 6 and a very limited narrow area around the substrate 6, except for the adhesion prevention plate, through the window IO provided therein so as to surround the substrate 6. The size of the window 10 is slightly larger than the size of the board. Note that a narrow space is provided between the window 10 and the substrate 6, which is large enough to accommodate the printer 12. In this embodiment, furthermore, fIl of Hofu &7
By attaching the partition plate 8 very close to the ls target 3, a shield 149 is provided in the thickness of the adhesion prevention plate. In addition to the above structure, the anti-adhesive plate 7 is made of the same material as the target 3, and the wire-wound heater 11 is wound around the anti-adhesive plate 67. This is a feature of the invention.

The effects brought about by the above-described structure of this embodiment will be explained below. An anti-adhesion plate 7 is provided to surround the target 3, and a window is opened only in the part facing the substrate 6.
By forming the film while stationary and facing each other, it is possible to prevent the sputtered film from adhering to the inner wall of the thin film forming chamber 1 and internal jigs such as the substrate holding jig 5. Of course, there is a possibility that sputtered atoms will diffuse through the narrow gap between the anti-adhesive e7 and the holding jig 5 and adhere to the inner wall surface of the Makabe container l or the surface of the holding jig Jt5 to which the substrate is not attached. That month is very low.

As a result, the problem of peeling of the film from walls and internal jigs can be resolved. Furthermore, by arranging the adhesion prevention plate 7 near the target periphery, the sputtered atoms flying from the target 3 are scattered less frequently by the sputtering gas, and their kinetic energy is relatively large. Therefore, the adhesion force of the sputtered atoms adhering to the adhesion prevention plate is 1 stronger than that when adhering to the wall, and peeling is also reduced. Furthermore, in the present invention, the adhesion prevention plate 7 is made of the same material as the target 3. As a result, the expansion coefficients of the film adhered to the adhesion prevention plate and the adhesion prevention plate become close to each other, so no large stress is applied to the film, and therefore, it is possible to suppress the peeling phenomenon of the film that generally occurs due to thermal history. . Therefore, it would be ideal if the materials of the adhesion prevention plate 7 and the target 3 were the same, but even if they are not exactly the same and have similar coefficients of thermal expansion, a significant effect can be obtained. For example, if the target 3 is made of molybdenum, the anti-adhesion device 7 may be made entirely of molybdenum plates.

Further, when the target 3 is a teta/-tungsten alloy, it is difficult to make a teta/-tungsten plate, so it is also effective to make the adhesion prevention plate from a titanium plate or a Toughgesten plate. The same applies when the target 3 is made of other materials. In addition, a wire-wound heater 11 coated with insulation is wound around the deposition prevention plate 7 and energized to heat the deposition prevention plate 7 to several hundred degrees Celsius before and during sputtering to strengthen the adhesion of the film. . In this way, by fabricating the anti-adhesion plate 7 using target material and l1iJ material and performing sputtering at high temperature, the adhesion strength of the sputtered film adhered to the anti-adhesion plate 7 can be dramatically increased, and the strength of the film can be increased. It became possible to prevent peeling.

In this way, one aspect of the present invention provides a method for suppressing the peeling of the film attached to the inside of the adhesion prevention plate as much as possible, and on the other hand, even in the event that peeling occurs, foreign forces can be released onto the substrate surface. Adhesion of foreign matter, or scattering of peeled films inside the thin film forming chamber? We will provide you with all the ways to prevent it.

2 from the surface of the target 3 with all of the anti-adhesive devices 7.
A groove 9 is provided by attaching a partition plate 8 at a distance of ~3cm. For this reason, the film attached to the inner surface of the adhesion-prevention plate 7 will fall into the groove 9 even if the knife is peeled off.1. target 3
Abnormal discharge will not occur between the and the adhesion prevention plate 7. Moreover, the fragments of the peeled-off membrane accumulate in the tube 9 and are not scattered in the vacuum chamber. To remove debris, use Jl'i
@,? , the cathode 2 and the target 3 are pulled out in the direction of the arrow 13. 4-The removal work can be carried out in a short time without exposing the inside of the vacuum chamber. Therefore, there is no fear of contaminating the inside of the vacuum chamber during the debris removal operation, and the vacuum chamber can be easily started up after one operation.

As mentioned above, the two main features of the present invention are molybdenum.

Even when materials such as tungsten, tetanta/guste, etc., which tend to produce surpluses, are formed using a continuous sputtering device, the thin film forming chamber can be kept in a vacuum for a long period of time. In addition, even if it does peel off, it can be easily removed in a short time, and can be used without sacrificing the features of a continuous sputtering device.

Note that the function of the partition plate 8 in the above-described embodiment is not limited to the plate shape as shown in FIG. 1, but may be one having a full slope as shown in FIG. 2, for example. Even in this case, sufficient effects as described above can be obtained. Furthermore, the structure of the Hofu board is not limited to the form described in the embodiment shown in FIG. 1, but can be transformed into the shape of the gods and performed rituals without departing from the gist of the present invention.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing the arrangement of a cathode, an adhesion prevention plate, and a substrate in a vacuum container according to the present invention. FIG. 2 is a sectional view showing another structure of the adhesion prevention plate. l...? vIj! i! Formation room, 2...
Sputtering cathode, 3... Sputtering target, 5... Substrate holding jig, 6...
... Board, 7 ... Adhesion prevention plate, 8 ... Group/partition plate, 9 ... Groove, io ... Adhesion prevention plate window, 1
1...The highest quality winding ν wire heater, 12.
...Indicates a shutter.

Claims (3)

[Claims] (1) In a sputtering apparatus that performs thin film formation with a substrate and a target placed in a vacuum-exhausted thin film forming chamber held vertically, and with the substrate and target stationary facing each other in a 1:1 ratio. , a cylindrical adhesion prevention plate covering the target 'fr is provided, and the open end of the nuclear adhesion prevention plate facing the substrate is slightly larger than the substrate and is located near the substrate. sputtering equipment. (2) The sputtering apparatus according to claim 1, wherein a wire-wound heater coated with insulation is wound around the deposition prevention plate to heat the nuclear prevention sign to a high temperature. (3) The sputtering apparatus according to claim 1, wherein the adhesion prevention plate is made of the same material as the target or a material having a similar number of thermal expansion threads.