JP4519416B2 - Anti-contamination device for thin film forming equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thin film forming apparatus, and more particularly to a contamination preventing apparatus for a thin film forming apparatus that can effectively prevent generation of particles during film formation by sputtering. In this specification, unless otherwise specified, peripheral devices in the thin film forming apparatus include a target and a backing plate.
[0002]
[Prior art]
2. Description of the Related Art In recent years, thin film formation technology by vapor phase growth has been used for many electrodes such as integrated circuit electrodes, diffusion barrier thin films, magnetic thin films for magnetic recording media, and ITO transparent conductive films for liquid crystal display devices. Thin film formation techniques by vapor deposition include thermal decomposition, hydrogen reduction, disproportionation, chemical vapor deposition such as plasma CVD, physical vapor deposition, sputtering, ion beam, etc. Vapor phase epitaxy, and discharge polymerization.
In particular, a sputtering method, which is one of the vapor phase growth methods, is widely used because it can be applied to a wide range of materials as described above and the control of thin film formation is relatively easy.
As is well known, this sputtering method bombards a sputtering target with charged particles, knocks out particles of the substance constituting the target from the target by the impact force, and arranges it facing the target. This is a film forming method in which a thin film is formed by attaching to a substrate such as a wafer.
[0003]
In forming a thin film by vapor phase growth such as sputtering as described above, the problem of generation of particles has been greatly taken up.
For example, this particle will be described with respect to a target-derived material in the sputtering method. When the target is sputtered, the thin film is deposited on the inner wall of the thin film forming apparatus and members inside the thin film forming apparatus in addition to the substrate. Then, it is considered that the flakes peeled off from the members or the like in the thin film forming apparatus are scattered and adhered directly to the substrate surface as one factor for the generation of particles.
[0004]
In addition, a foreign matter called a nodule, which is considered to be generated with a flake peeled off from a target side surface or a member in the thin film forming apparatus as a nucleus, grows on the target surface to a diameter of about several μm. Such nodules are considered to be a factor in the generation of particles by crushing when they grow to some extent and scattering and adhering to the substrate surface.
When the above-mentioned particles are deposited on thin wirings on the substrate, for example, in the case of LSI, problems such as short-circuiting of wirings and conversely disconnection occur.
[0005]
Recently, the degree of integration of LSI semiconductor devices has increased (16 Mbits, 64 Mbits or even 256 Mbits, etc.), while the wiring width (rule) has become smaller, such as being 0.25 μm or less. Problems such as wire breakage and short circuit due to particles have become more frequent. As described above, as the degree of integration and miniaturization of electronic device circuits progresses, the generation of particles has become a bigger problem.
[0006]
As described above, as one of the causes of particle generation, there is a large problem of thin film deposition on the inner wall of the thin film forming apparatus and members existing on the inside where the film formation is unnecessary. Raised. Specifically, it is deposition on the periphery of the substrate, shield, backing plate, shutter, target, and their support.
[0007]
As described above, since unnecessary thin film is deposited, this film is peeled off and scattered to cause generation of particles. Therefore, these deposits become thick and before the peeling, The inner wall and the peripheral part of the substrate, the shield, the backing plate, the shutter, the target, and the support thereof are regularly cleaned or replaced.
In addition, a metal spray coating is formed on a member (equipment) that is deposited in large quantities so that a thin film once adhered is not peeled off or scattered again (see Patent Documents 1 and 2) or physical processing such as blasting. Means was taken to capture the deposits by performing a surface roughening treatment (see Patent Document 3).
[0008]
Furthermore, since the above-described work was considered to be a cause of lowering the work efficiency of thin film formation, a removable plate called an anti-adhesion plate that captures deposits so as not to peel off and scatter is devised. The invention has been devised such as changing the coefficient of thermal expansion of the plate and performing sandblasting or hairline treatment on the surface of the plate (see Patent Documents 4, 5, and 6).
Among these, a so-called particle getter with special surface treatment was an epoch-making one that effectively prevented the generation of particles in the technology at that time (see Patent Documents 7 and 8). .
However, when replacing the particle getter such as the inner wall of the thin film forming device or the periphery of the substrate, shield, backing plate, shutter, target, etc., remove the particle getter from the spot welded equipment, and then reapply the new particle getter there. A fairly complicated operation of attaching by welding or the like is necessary. In addition, there has been a problem that it is necessary to pause the thin film forming apparatus during the replacement work.
[0009]
[Patent Document 1]
JP 61-56277 A [Patent Document 2]
JP-A-8-176816 [Patent Document 3]
Japanese Patent Laid-Open No. 62-142758 [Patent Document 4]
Japanese Patent Laid-Open No. 63-162861 [Patent Document 5]
JP-A-2-285067 [Patent Document 6]
Japanese Patent Laid-Open No. 3-138354 [Patent Document 7]
JP-A-1-316456 [Patent Document 8]
Japanese Patent Laid-Open No. 3-87357
[Problems to be solved by the invention]
The present invention facilitates replacement of the particle getter in the thin film forming apparatus, can shorten the rest period of the apparatus, and deposits formed on the inner wall of the thin film forming apparatus or on the surface of the equipment member inside the apparatus An object of the present invention is to provide a pollution control device for a thin film forming apparatus that can effectively prevent the peeling of objects and suppress the generation of particles.
[0011]
[Means for Solving the Problems]
The present invention
1. In a thin film forming apparatus, a metal foil that captures substances adhering to peripheral equipment other than the substrate can be attached to a support plate in advance, and one or more of the support plates attached with the metal foil can be replaced with equipment in the thin film forming apparatus. 1. Antifouling device for thin film forming apparatus, characterized by being installed in 2. The antifouling device for thin film forming apparatus as described in 1 above, wherein the metal foil is attached to the support plate by spot welding. 3. The antifouling device for a thin film forming apparatus according to 1 or 2 above, wherein the support plate is a metal plate such as stainless steel, titanium or aluminum. 4. The contamination preventing apparatus for a thin film forming apparatus according to any one of the above 1 to 3, wherein the device in the thin film forming apparatus is a shield. 5. The thin film forming apparatus according to 4 above, wherein a taper is provided on the upper surface of the shield edge portion for preventing adhesion to the substrate, and a support plate having a metal foil attached to the surface covering the taper is installed. 5. Anti-contamination device for use 6. The antifouling device for a thin film forming apparatus as described in 5 above, wherein the taper has a width of 20 to 30 mm.
[0012]
The present invention also provides: 7. The contamination prevention apparatus for a thin film forming apparatus according to 5 or 6 above, wherein a support plate on which metal foil is spot-welded at intervals of 5 to 15 mm is installed in a taper. 8. The anti-contamination device for thin film forming apparatus according to 7 above, wherein spot welds other than the taper are welded at intervals of 5 to 50 mm. 9. The antifouling device for a thin film forming apparatus according to any one of 1 to 8 above, wherein a plurality of support plates are densely installed with a gap of 1 mm or less. 10. The antifouling device for a thin film forming apparatus as described in any one of 1 to 9 above, wherein the support plate is fixed by mechanical means such as hooking, fixing and screwing. 11. The anti-contamination device for a thin film forming apparatus according to any one of 1 to 10 above, wherein the thin film forming apparatus is a sputtering apparatus. 12. The contamination preventing apparatus for a thin film forming apparatus according to any one of the above 1 to 11, wherein the support plate has a thickness of 0.5 to 3 mm. A macro unevenness is formed on the surface of the exposed part in the thin film forming device of the fixing device that is fixed by mechanical means such as hooking, fixing and screwing the support plate, and further forming micro unevenness by blasting etc. 14. A contamination preventing apparatus for a thin film forming apparatus according to any one of 1 to 11 above, wherein the apparatus has a rough surface with a surface roughness Ra of 1 to 20 μm. The contamination prevention device for a thin film forming apparatus according to any one of 1 to 12 above, wherein the support plate is divided and the weight of one sheet is 3 kg or less.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The anti-contamination device for a thin film forming apparatus of the present invention can be applied to all devices such as shutters, substrate shields (masks), magnetic shields, inner walls, etc., targets, backing plates, etc. in the thin film forming apparatus.
Also, as a thin film forming apparatus, a pyrolytic thin film forming apparatus, a hydrogen reduction thin film forming apparatus, a thin film forming apparatus using a disproportionation reaction, a chemical vapor deposition thin film forming apparatus such as a plasma CVD thin film forming apparatus, a vacuum deposition apparatus, a sputtering It can be used for all apparatuses such as an apparatus, a physical vapor deposition apparatus such as an ion beam thin film forming apparatus, and a discharge polymerization thin film forming apparatus. In particular, it is effective for a sputtering apparatus.
[0014]
The antifouling device for a thin film forming apparatus of the present invention attaches a metal foil that captures substances adhering to peripheral equipment other than the substrate to a support plate in advance, and uses the support plate with the metal foil attached to the equipment in the thin film forming apparatus. Install in a replaceable manner.
Metal foil is a copper foil (common name: particle getter) with numerous irregularities (copper oxide fine particle layer on the copper foil) formed on the surface, similarly treated iron foil, Ti foil, nickel plated foil, copper plated foil Further, foils formed on bellows, embossed foils, blasted foils, pickled foils, etc., and foils having a surface roughness Ra of 1 μm or more can be used.
Ra1 to 7.5 μm is preferable. This roughness has the effect of enhancing the anchor effect, improving the adhesion of the scattered material, and greatly reducing the occurrence of peeling.
Moreover, as thickness of these metal foil, foil of 10-500 micrometers thickness can be used. The preferred thickness is 30 to 250 μm, and particularly preferably 70 to 150 μm. Since the support plate serves as a reinforcement, thin foil can also be used.
[0015]
The support plate is a rectangular (rectangular), L-shaped or other thin metal plate that matches the shape of the device. Since the support plate can be divided and installed in a thin film forming apparatus, the shape can be changed variously.
As the material, stainless steel is preferable because it can easily obtain a clean surface, has good weldability, has high strength, has excellent corrosion resistance, and is inexpensive. Titanium and aluminum can be used similarly.
The thickness of the support plate is 0.5 to 3 mm, preferably 1 to 2 mm. Further, it is desirable that the support plate is divided so that the weight of one sheet is 3 kg or less.
In the thin film forming apparatus, it is simple and recommended to fix the support plate by mechanical means such as hooking and screwing. In addition, there is an advantage that the mounting position can be reduced. However, such an attachment method is not particularly limited.
[0016]
Macro unevenness (approx. 0.1 mm or more at maximum height difference) is formed on the surface of the exposed part in the thin film forming device of the fixing tool that is fixed by mechanical means such as hooking, fixing and screwing the support plate. Further, it is desirable to form micro unevenness by a blasting process to obtain a rough surface having a surface roughness (centerline average roughness) Ra1 to 20 μm. As a result, it is possible to prevent the separation of contaminants even in a small area. A cap may be attached to the exposed portion of the fixing tool, and irregularities may be formed there to form a rough surface.
It is desirable that the metal foil is firmly attached to the support plate by spot welding. Since the support plate can be prepared before being installed in the thin film forming apparatus, the replacement speed is much faster than in the prior art. A metal plate serving as a support plate such as stainless steel, titanium, or aluminum serves to reinforce a weak metal foil. This has the effect of facilitating mounting in the thin film forming apparatus.
[0017]
FIG. 1 shows an integral shield 1 used in a sputtering apparatus (the shield may be referred to as a mask). There is a taper 2 inside. The shield 1 is attached to a support structure (device) with a shield fixing screw 3. The roughened copper foil 4 of the present invention is spot-welded to a stainless steel plate 5 serving as a support plate having a thickness of 1.2 mm, for example, and fixed with a cap screw 6 or the like.
The stainless steel plate 5 serving as a support plate serves as a reinforcement for the copper foil 4 having a low waist. Further, since the stainless steel plate 5 used in this case has high corrosion resistance, there is an advantage that there is no corrosion and no diffusion of contaminants due to corrosion inside the sputtering apparatus even in a corrosive atmosphere.
[0018]
FIG. 2 shows a cross section of the fixing portion. The head of the shield fixing screw 3 is covered with a cap 6. Macro unevenness is formed on the surface of the cap 6, and micro unevenness is formed by blasting or the like to obtain a rough surface having a surface roughness Ra of 1 to 20 μm.
The weight of one stainless steel plate 5 spot-welded to the copper foil 4 is 1500 g, and attachment and removal with screws 6 can be performed very easily. Further, the support plate 5 to which the used metal foil 4 is attached is usually discarded as it is (recycling as a material is possible).
[0019]
FIG. 3 shows an example in which the support plate 7 divided into four parts is installed on the shield as shown in FIG. A copper foil (particle getter) is attached to each support plate 7. The clearance 8 between the support plates 7 is 1 mm or less.
FIG. 4 shows an example in which an inner shield 9 and an outer shield 10 are provided. The inner shield 9 has a tapered portion 2 inside and is structurally the same as the integrated type. Similarly, the roughened copper foil 4 of the present invention can be bonded by spot welding to a stainless steel plate 5 serving as a support plate having a thickness of 1.2 mm, for example, and fixed by a cap screw 6 or the like.
[0020]
The contamination prevention apparatus for a thin film forming apparatus of the present invention is particularly effective when used for a shield such as sputtering. In general, a taper is provided on the upper surface of the shield edge portion for preventing adhesion to the substrate. However, it is effective to install a support plate having a metal foil attached to the surface covering the taper.
In particular, a large amount of material adheres to this surface and often causes generation of particles. Therefore, it is necessary to increase the accuracy of preventing contamination. The taper has a width of 20 to 30 mm, and a support plate is used in which a metal foil is spot-welded at intervals of 5 to 50 mm on the surface of the taper.
[0021]
The taper portion is a portion where the deposited film thickness is increased and stress is greatly applied. In particular, when the spot welded portion is less than 5 mm (dense) or exceeds 50 mm, in any case, peeling of the film easily occurs. The moderate deformability of the foil has an effect of suppressing peeling. Furthermore, as described above, it is possible to effectively prevent peeling from the welded portion by making the spot welded portion denser than other places.
When welding to the support plate, it is desirable to weld spot welds other than the taper at intervals exceeding 15 mm. Dense spot welding reduces workability (regeneration process). It is desirable that the plurality of support plates be densely installed at intervals of 1 mm or less in order to enhance the contamination prevention effect. The adhesion force due to the anchor effect can be effectively exhibited.
[0022]
【The invention's effect】
The anti-contamination device for thin film forming apparatus of the present invention makes it easy to replace the anti-polluting device (particle getter), shorten the downtime of the apparatus, and the inner wall and apparatus of the thin film forming apparatus. It is possible to effectively prevent the deposits formed on the surface of the device member inside the substrate from being peeled off and to suppress the generation of particles.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of an integral shield device of a sputtering apparatus.
FIG. 2 shows a cross section of an attachment portion for fixing a shield and a support plate.
FIG. 3 is a view showing an example in which a four-part support plate having a particle getter (copper foil) attached to a shield is installed.
FIG. 4 is a diagram illustrating an example of a shield device including an inner shield and an outer shield of a sputtering device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Integrated shield 2 Tapered part 3 Shield fixing screw 4 Copper foil 5 Support plate 6 Cap screw 7 Divided support plate 8 to which particle getter (copper foil) is attached Clearance 9 Inner shield 10 Outer shield

Claims (11)

  A metal foil that captures substances adhering to shields around the substrate other than the substrate is attached to the support plate in advance, and one or more of the support plates attached to the metal foil are installed so as to be replaceable with the shield in the thin film forming apparatus. A device for preventing contamination of an apparatus, wherein a taper is provided on the upper surface of the edge portion of the shield, and a support plate having a metal foil for capturing the adhering substance attached to the surface covering the taper of the shield is installed in a replaceable manner. An anti-contamination device for a thin film forming apparatus.   2. The antifouling device for a thin film forming apparatus according to claim 1, wherein the metal foil is attached to the support plate by spot welding.   3. The pollution control device for a thin film forming apparatus according to claim 1, wherein the support plate is a metal plate such as stainless steel, titanium, or aluminum.   The contamination prevention apparatus for a thin film forming apparatus according to any one of claims 1 to 3, wherein the taper has a width of 20 to 30 mm.   The contamination prevention device for a thin film forming apparatus according to any one of claims 1 to 4, wherein a support plate on which metal foil is spot-welded at intervals of 5 to 50 mm is installed in a taper.   The pollution control device for a thin film forming apparatus according to any one of claims 1 to 5, wherein a plurality of support plates are densely installed with a gap of 1 mm or less.   7. The anti-contamination device for a thin film forming apparatus according to claim 1, wherein the support plate is fixed by mechanical means such as hooking, fixing and screwing.   The contamination prevention apparatus for a thin film forming apparatus according to claim 1, wherein the thin film forming apparatus is a sputtering apparatus.   The contamination prevention apparatus for a thin film forming apparatus according to any one of claims 1 to 8, wherein the support plate has a thickness of 0.5 to 3 mm.   Form macro unevenness in the exposed part in the thin film forming device of the fixing tool that is fixed by mechanical means such as hooking, fixing and screwing the support plate, and further forming micro unevenness by blasting etc. The contamination preventing apparatus for a thin film forming apparatus according to any one of claims 1 to 9, wherein the apparatus has a rough surface with a surface roughness Ra of 1 to 20 µm. The contamination prevention apparatus for a thin film forming apparatus according to any one of claims 1 to 10 , wherein the support plate is divided so that the weight of one sheet is 3 kg or less.

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