JP2568141B2 - Thin film forming equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film forming apparatus having an ignition preventing particle getter having an oxygen-containing layer or an oxygen-enriched layer containing fine particles of copper oxide formed on the matte surface of an electrolytic copper foil. The present invention relates to a thin film forming apparatus that prevents the generation of particles and also prevents ignition when the apparatus is exposed to the atmosphere. The oxygen-containing layer means a layer containing fine particles of copper oxide formed on the matte surface of the electrolytic copper foil, and the oxygen-enriched layer means that after the oxygen-containing layer is formed, it is further heat-treated in an oxygen-containing atmosphere. Refers to the more oxygen-enriched layer formed by.

[0002]

2. Description of the Related Art Conventionally, vapor phase growth technology has been used to form many thin films such as thin films for electrodes and diffusion barriers of integrated circuits, magnetic thin films for magnetic recording media, and ITO transparent conductive films for liquid crystal display devices. Has been done. The thin film forming technology by this vapor phase growth method includes thermal decomposition method, hydrogen reduction method, non-uniformization reaction method,
There are chemical vapor deposition such as plasma CVD method, vacuum deposition method, sputtering method, ion beam method, and discharge polymerization method.

At present, such a thin film forming process by the vapor phase growth method has been established as a mass production technique, but the problem that coarse particles generally called particles are deposited on the formed film occurs. ing. The particles are particles formed by clustering when a thin film is formed on the substrate, and the particles have a diameter of several μm.
Since many of them grow to a certain degree, if they are deposited on the substrate, problems such as short-circuiting of wiring or conversely disconnection occur in the case of LSI, which causes an increase in the defective rate. These particles have various factors such as those caused by the thin film forming method itself and those caused by the coating device.

As the particles caused by the thin film forming apparatus as described above, the deposited film adhering to the periphery of the substrate, the inner wall (furnace wall) of the apparatus, the shutter, the shield plate and the like is peeled off and scattered to adhere to the substrate. One of the major factors is that it becomes a pollution source. In order to prevent particles due to such re-peel of the adhered substance, it is necessary to keep the inner wall of the thin film forming apparatus clean. It is actually very difficult to keep such inner walls clean at all times, it takes a lot of time to be completely clean, and some parts of the inner walls and equipment cannot actually be cleaned. .

As one of the countermeasures, Al foil or electrolytic Fe
The use of pollution control materials with disposable foil foil was considered. It was considered possible to keep the inner wall in a clean state by attaching these foils to the inner wall in advance and removing this after the thin film formation (covering operation). However, fatal defects were found in these disposable foils. That is, the thin film-forming scattered material deposited on the installed foil is easily separated, and particles are still generated on the deposited film on the substrate. To prevent this peeling, the foil must be changed frequently,
The operability of thin film formation deteriorated significantly.

Under the circumstances, the applicant of the present invention has previously proposed the use of treat electrolytic copper foil in place of the conventional metal foil (JP-A-1-316456). Treated electrolytic copper foil is an electrolytic copper foil with a matte surface (matte surface) that is further subjected to electrolytic treatment to randomly deposit minute copper or copper oxide fine particles (knobs) on the matte surface. It was deposited on. The copper foil having such fine grain projections is excellent in capturing the flying particles and is excellent in that the deposited layer on the copper foil is fixed and held by the anchor effect or the pinning effect. These are called particle getters because they effectively prevent the generation of particles.

[0007]

A new problem has come to be emphasized in a thin film forming apparatus by vapor phase growth of a metal, alloy or compound such as titanium which is active against oxygen. It is a problem of ignition of active metals. When a metal or alloy that is active against oxygen is formed by vapor deposition or sputtering in an inert atmosphere or under vacuum,
Since the amount of residual oxygen in the atmosphere is very low, scattered particles are deposited on the particle getter in an activated state, and when several hundred μm or more is deposited, the internal stress generated in the deposited film exceeds the adhesion force. As a result, it peels off and becomes small pieces or fine powder that scatters and floats inside the device again. As a result, these metal and alloy particles and fine powders exist in a state where they are highly activated with respect to oxygen and have a large reaction area with oxygen.

[0008] When the device is opened to the atmosphere for cleaning or maintenance, the active deposits or scattered small particles or fine powder reacts rapidly with oxygen in the atmosphere, ignites and burns, and cleaning and maintenance work is difficult. It can be dangerous and dangerous. It can even damage the device. Also, regarding the storage and scrap processing of the collected deposits, there is a risk of ignition and combustion, and they are stored in water in a metal container with an open or lid for a long period of time, and scrap processing is performed by observing the degree of discoloration of the deposit surface. It was very difficult to do.

The object of the present invention relates to deposits deposited on a particle getter arranged in a thin film forming apparatus by vapor phase growth of a metal, alloy or compound such as titanium which is active against oxygen. It is to overcome the above ignition problem when the device is opened or the deposit is stored.

[0010]

The present inventors have formed an oxygen-containing layer or an oxygen-enriched layer on an electrolytic copper foil during the deposition of a deposit on a particle getter in order to inactivate the deposit. , The oxygen contained therein was absorbed and diffused in the deposit to inactivate the deposit, and the result of the trial was good. Thus, the present invention relates to (i) oxygen containing copper oxide fine particles on the matte surface of an electrolytic copper foil in a thin film forming apparatus by vapor phase growth of a metal, alloy or compound which is more active than oxygen against copper. Oxygen enrichment by forming an oxygen-containing layer containing fine particles of copper oxide on the matte surface of an electrolytic copper foil or an ignition-preventing particle getter on which the containing layer is formed, and then performing heat treatment in an oxygen-containing atmosphere. A layered anti-fire particle getter is placed in the device, and the anti-particle getter captures and deposits particles flying in the device and at the same time inactivates the deposit to oxygen. A thin film forming apparatus is provided. Specifically, the oxygen content of the copper foil on which the oxygen-containing layer is formed is 0.1.
The oxygen content of the copper foil having the oxygen-enriched layer is 1.0 wt% or more and 5.0 wt% or less. Preferably, the electro-deposited copper foil is corrugated or embossed to absorb the internal stress generated in the deposit. The surface roughness Rz of the electrolytic copper foil having the oxygen-containing layer or the oxygen-enriched layer is 5 to 10 μm.
It is desirable that

[0011]

[Function] The deposited layer of metal, alloy or compound which is very active against oxygen is fixed on the particle getter so as not to peel and scatter, the reaction area with oxygen is reduced, and the copper foil surface contains oxygen. Oxygen-containing layer or oxygen-enrichment on the surface of the copper foil in the active metal, alloy or compound deposits deposited on the copper foil by forming a layer or further oxygen-enriching it to form an oxygen-enriched layer It absorbs and diffuses oxygen from the layer, inactivates the deposited layer to oxygen, and overcomes the above ignition problems associated with deposits deposited on the particle getter during equipment opening or deposit storage.

[0012]

The thin film forming apparatus by vapor phase epitaxy of the present invention is particularly applicable to a thermal decomposition method, a hydrogen reduction method, a non-uniformization reaction method, a transport reaction method, a plasma, which handles metals, alloys or compounds active against oxygen. Chemical vapor deposition (CVD) such as CVD and low pressure CVD, vapor phase epitaxy (VPE) method, vacuum deposition method, sputtering method, molecular beam epitaxy (MBE)
Method, an ion beam method, a discharge polymerization method, or the like, means a thin film forming apparatus by a vapor phase growth method. An ignition preventive particle getter is provided on the inner wall of such a device and on a portion of the surface of a device / part such as a shutter, a shield plate, a bolt, and a nut, which is provided in the device, where thin film formation is unnecessary.

Examples of such oxygen-active metals, alloys or compounds are metals such as titanium, zirconium, aluminum and their alloys or compounds such as silicides of these metals.

The electrolytic copper foil (green foil) before forming the oxygen-containing layer or the oxygen-enriched layer of the present invention has fine lump-shaped protrusions (knobs) on the matte surface (matte surface). . By subjecting this to electrolytic treatment, an oxygen-containing layer containing copper oxide fine particles is randomly deposited on the minute lump-shaped protrusions (knobs) present on the electrolytic copper foil mat surface, and the oxygen-containing layer in the copper foil is contained. The ratio is 0.1 wt% or more and less than 1.0 wt%. It is necessary to form the oxygen-containing layer as an oxygen source sufficient to inactivate the deposits with respect to oxygen. Oxygen content is at least 0.1 wt% to supply sufficient oxygen
is necessary. An example of electroplating conditions for forming an oxygen-containing layer containing fine oxide particles is shown below: (A) Water-soluble copper sulfate plating bath CuSO ₄ .5H ₂ O, g / l (as Cu): 23 NaCl, ppm (as Cl): 32 H ₂ SO ₄ , g / l: 70 glue, g / l: 0.75 pure water: balance (B) plating conditions current density: 60-100 A / ft ² bath temperature: 70- 80 ° F time: 10 to 100 seconds Under electroplating conditions, the longer the plating time,
The oxygen content of the oxygen-containing layer increases.

Further, in order to maintain the effect of inactivation for a sufficiently long period, it is effective to perform the following oxygen enrichment treatment in addition to the above electrolysis treatment.
That is, a copper foil having an oxygen-containing layer formed by electrolytic treatment is heat-treated in an oxygen-containing atmosphere to form an oxygen-enriched layer, and copper having an oxygen content of 1.0 wt% or more and 5.0 wt% or less. It is to get foil. The heating atmosphere may be any atmosphere as long as it contains oxygen, but it is cost effective to perform it in the atmosphere. It was found that the longer the heat treatment time, the higher the oxygen content in the copper foil, but a maximum of 5.0 wt% oxygen is sufficient as long as it deactivates the deposited active metal and the like.

The copper foil having an oxygen-containing layer or an oxygen-enriched layer produced by these steps has a surface roughness Rz of 5.
It is desirable that the thickness is in the range of 0 to 10.0 μm. Since the protrusions due to the roughness are present, the adhesion effect with the deposit formed by depositing the scattered substances is improved by the anchor effect, and the peeling phenomenon is less likely to occur.

However, the thickness of the deposited layer is 100 μm.
In the above case, the internal stress of the deposited layer tends to exceed the fixing force, and the deposited layer peels off from the copper foil and scatters as small pieces or fine particles. In order to absorb the internal stress generated in the deposit, it is desirable to process the electrolytic copper foil in a wavy or embossed shape.

According to the present invention, the active metal, alloy or compound deposited on the copper foil is formed by forming an oxygen-containing layer on the surface of the copper foil or by oxygen-enriching it to form an oxygen-enriched layer. The oxygen from the oxygen-containing layer or the oxygen-enriched layer on the surface of the copper foil is absorbed and diffused in the deposit of (1) to inactivate the deposited layer with respect to oxygen. Therefore, the above ignition problem at the time of opening the device or storing the deposit, which is associated with the deposit deposited on the particle getter, is overcome.

When copper is plated as an oxygen-containing treatment in an electrolytic bath containing an organic additive, the fine particle thin layer may have the organic additive attached to its surface. Therefore, in order to prevent the inside of the thin film forming apparatus from being contaminated by the organic additive, it is desirable to perform ultrasonic cleaning with an organic solvent such as acetone or alcohol or heated ultrapure water before use. Note that vacuum heating may be performed for the purpose of drying after cleaning. When heating in vacuum, the maximum is 8 so that surface protrusions do not change due to growth phenomena.
It is necessary to suppress the temperature to 00 ° C.

The copper foil having an oxygen-containing layer or an oxygen-enriched layer has a brass or zinc barrier layer formed thereon for heat resistance, as described in JP-B-54-6701. It can also be rustproofed to prevent excessive oxidation during transport or storage.

The copper foil preferably has a thickness of 20 to 350 μm.
0 to 250 μm is preferable. If it is too thin, wrinkles are likely to occur when it is set in the apparatus, and if wrinkles are formed, it may cause the peeling of deposits, so it should be avoided. On the other hand, if the thickness is too large, the operability when set in the device is deteriorated and it is disadvantageous in terms of cost.

Next, the present invention will be described based on Examples and Comparative Examples.

(Examples and Comparative Examples) Treated copper foils were subjected to oxygen enrichment treatment at 200 ° C. for 30 minutes in the atmosphere, electrolytic copper foils (oxygen content: 1.6 wt%) and SUS stainless steel sheets with Ti films respectively. A 1 μm film was formed by sputtering. FIG. 1 shows the concentration distribution state of copper and oxygen in the depth direction by Auger spectroscopic analysis on the matte side of the electrolytic copper foil before Ti film formation. In FIG. 1, a high oxygen concentration region is observed in the vicinity of the surface over 1 μm or more. FIG. 2 shows T along the depth direction in a Ti film formed on an electrolytic copper foil subjected to oxygen enrichment treatment.
The concentration distribution of i, Cu, and O is shown. FIG. 3 shows Ti, O, Fe along the depth direction in the Ti film formed on the SUS plate.
3 shows the concentration distribution of Cr and Cr. As shown in FIG. 2, the oxygen concentration distribution shows that the Ti-
An almost constant oxygen concentration was shown toward the copper foil interface, and the tendency did not change even at the Ti-copper foil interface, and the oxygen concentration near the copper foil surface existing before the Ti film formation as shown in FIG. High areas are not observed. On the other hand, T formed on the SUS plate
Regarding the oxygen concentration distribution in the i film, the oxygen peak intensity drops to the background noise level except for the several atomic layers near the surface, and the oxygen concentration is extremely low. From the above, as shown in FIGS. 4 to 6 which schematically explain the oxygen concentration in FIGS. 1, 2 and 3, oxygen in the oxygen-enriched layer extending over 1 μm or more on the matte surface of the electrolytic copper foil is Ti. When the film is formed, it is absorbed and diffused in the Ti film, so that the oxygen concentration in the Ti film becomes high. That is, Ti is inactivated with respect to oxygen. On the other hand, the Ti film formed on the SUS plate has a low oxygen concentration and Ti is deposited in an activated state.

Next, as a result of evaluating the ignitability by a scratch test by rubbing with # 600 sandpaper,
The Ti film formed on the oxygen-enriched electrolytic copper foil did not ignite, but the Ti film formed on the SUS plate did.

[0025]

EFFECTS OF THE INVENTION It is possible to prevent ignition and combustion of a device such as cleaning and maintenance of a thin film forming device when it is opened to the atmosphere, and to make cleaning work safe and easy. As for the storage and scrap disposal method of the deposits after recovery, it is possible to eliminate the long-term inactivation treatment required for ignition / fire prevention measures, which is conventionally required, and dispose of the deposits safely and easily. be able to.

[Brief description of drawings]

FIG. 1 shows the concentration distribution state of copper and oxygen in the depth direction by Auger spectroscopic analysis on the matte side surface of an electrolytic copper foil subjected to oxygen enrichment treatment before Ti film formation.

FIG. 2 Ti and C by Auger spectroscopy along the depth direction in a Ti film formed on an oxygen-enriched electrolytic copper foil
The concentration distribution of u and O is shown.

FIG. 3 shows the concentration distributions of Ti, O, Fe, and Cr in the Ti film formed on the SUS plate by Auger spectroscopy along the depth direction.

FIG. 4 is an explanatory view schematically explaining only the oxygen concentration distribution of FIG.

FIG. 5 is an explanatory view schematically explaining only the oxygen concentration distribution of FIG.

FIG. 6 is an explanatory diagram schematically explaining only the oxygen concentration distribution of FIG.

Front page continuation (72) Shinichi Kanao 5-20-1 Kamimizuhoncho, Kodaira-shi, Tokyo Inside the Musashi Factory, Hitachi Ltd. (72) Susumu Sawada 187 Usba, Hwagawa-cho, Kitaibaraki-city, Ibaraki Address 4 days Main Mining Co., Ltd. Isohara Factory (72) Inventor Yoshitaka Sumiya, 187 Usuba, Hachikawa-cho, Kitaibaraki City, Ibaraki Prefecture Address 4 days Main Mining Co., Ltd. Isohara Factory (72) Inventor Hironori Wada Hana Kitabaraki, Ibaraki Prefecture Kawamachi Usoba No.187, 4th, Minoru Co., Ltd. Isohara factory (56) Reference JP-A-1-188672 (JP, A)

Claims (8)

(57) [Claims] 1. A thin film forming apparatus by vapor phase growth of a metal, alloy or compound which is more active than oxygen against copper,
An ignition preventive particle getter having an oxygen-containing layer containing fine copper oxide particles formed on the matte surface of the electrolytic copper foil is disposed in the device, and the particles scattered in the device are captured by the ignition preventive particle getter, and A thin film forming apparatus characterized in that it is deposited there, and at the same time, the deposit is inactivated by oxygen. 2. The thin film forming apparatus according to claim 1, wherein the electrolytic copper foil having the oxygen-containing layer has an oxygen content of 0.1 wt% or more and less than 1.0 wt%. 3. The electrolytic copper foil having an oxygen-containing layer formed thereon is corrugated or embossed.
Thin film forming equipment. 4. The thin film forming apparatus according to claim 1, wherein the electrolytic copper foil having the oxygen-containing layer has a surface roughness Rz of 5 to 10 μm. 5. A thin film forming apparatus by vapor phase growth of a metal, alloy or compound which is more active than oxygen against copper,
An anti-ignition particle getter with an oxygen-enriched layer formed by forming an oxygen-containing layer containing fine copper oxide particles on the matte surface of electrolytic copper foil and then heat-treating it in an oxygen-containing atmosphere was placed in the device. A thin film forming apparatus, which is provided, wherein particles that fly in the apparatus are captured by the ignition preventive particle getter and deposited there, and at the same time, the deposit is inactivated by oxygen. 6. The thin film forming apparatus according to claim 5, wherein the electrolytic copper foil having the oxygen-enriched layer has an oxygen content of 1.0 wt% or more and 5.0 wt% or less. 7. The electro-deposited copper foil having an oxygen-enriched layer formed thereon is corrugated or embossed.
Thin film forming equipment. 8. The thin film forming apparatus according to claim 5, wherein the electrolytic copper foil having the oxygen-enriched layer has a surface roughness Rz of 5 to 10 μm.