JP3907402B2 - Dummy wafer - Google Patents

Description

【００６８】
実施例１〜３のダミーウェハーは、せん断吸着力が０．０３Ｎ／ｃｍ²、ダストかみ込み時吸着力低下が９２以上であり、ダスト付着時のせん断吸着力が極めて優れていることが確かめられた。また、キズの発生も全く見られず、破損が極めて少ないことが分かった。また、センサー認識性についても、検出エラーが全く見られず、光センサーによる検知が良好に行われていることが分かった。
【００６９】
また、搬送性についても、所定の位置に設置できなかったものが全く無く、搬送性が向上していることが分かった。耐熱性についても、異常が全く認められず、極めて良好な状態であることが確認された。金属汚染についても、全く問題がなかった。
【００７０】
一方、比較例１は、搬送性、耐熱性、金属汚染については問題が無かったものの、せん断吸着力が０．０１Ｎ／ｃｍ²であり、また、ダストかみ込み時吸着力低下が４８と大きく低下し、ダスト付着時のせん断吸着力が劣っていることが分かった。また、キズの発生が認められ、センサー認識性についても、検出エラーが発生しており、光センサーによる検知が良好に行われないことが分かった。
比較例２は、せん断吸着力が０．０１Ｎ／ｃｍ²、ダストかみ込み時吸着力低下が９３であり、キズ、搬送性、金属汚染については問題が無かったものの、センサー認識性及び耐熱性が劣っていることが確かめられた。
【００７１】
比較例３は、せん断吸着力が０．０６Ｎ／ｃｍ²と極めて高く、耐熱性についても問題が無かったものの、ダストかみ込み時吸着力低下が４２と低く、キズの発生も認められ、センサー認識性及び耐熱性も劣っており、金属汚染ではＮｉが検出された。
比較例４は、せん断吸着力が０．０２Ｎ／ｃｍ²、ダストかみ込み時吸着力低下が９５であり、キズ、センサー認識性、搬送性、金属汚染については問題が無かったものの、耐熱性が劣っていることが確かめられた。
【００７２】
以上、本発明のダミーウェハーの各実施形態について図面に基づき説明してきたが、具体的な構成は本実施形態に限定されるものではなく、本発明の要旨を逸脱しない範囲で設計の変更等が可能である。
例えば、本実施形態のダミーウェハーは、半導体製造プロセスにおいて用いられるシリコンウェハーと略同一の径で、その重量がシリコンウェハーと略同一の重量となるように構成したが、その径や重量については適宜変更可能であり、シリコンウェハーと全く同一とする必要性は全く無い。
【００７３】
【発明の効果】
以上説明した様に、本発明のダミーウェハーによれば、板状の基体の一方の主面または両方の主面に、接着剤層を介して導電体層と樹脂フィルムが形成されたので、この導電体層とサセプターとの距離を短縮することができ、より大きな静電吸着力を得ることができる。
また、樹脂フィルムに直接導電体層を形成したものであるから、積層部分の総膜厚さを薄くすることができ、その分、基体自体の厚みを厚くすることができ、ダミーウェハーの長寿命化、反りの減少を図ることができる。
また、導電体層の表面が樹脂フィルムにより覆われることとなるので、発塵源となるおそれが無く、金属汚染を防止することができる。
【００７４】
また、前記導電体層と前記樹脂フィルムとの間に、薄厚の下地層を形成すれば、前記導電体層と前記樹脂フィルムとの間に熱膨張率差があった場合においても、剥離等を防止することができる。
また、前記導電体層を、前記基体より面積が狭く、かつ、その端縁部を前記接着剤層により覆った構成とすれば、スパッタ装置等に用いた場合に、前記導電体層の放電を防止することができる。
以上により、軽量で、搬送性が良く、破損、ダスト、金属汚染が少なく、静電吸着力が強く、光センサによる検知が可能で、繰り返し使用することができると共に、安価な、ダミーウェハーを提供することができる。
【図面の簡単な説明】
【図１】 本発明の第１の実施形態のダミーウェハーを示す断面図である。
【図２】 本発明の第２の実施形態のダミーウェハーを示す断面図である。
【符号の説明】
１ ウェハー基体（板状の基体）
１ａ 表面（一方の主面）
２ 接着剤層
３ 導電体層
４ 耐熱性樹脂フィルム
５ 下地層[0001]
BACKGROUND OF THE INVENTION
The present invention is suitably used when performing a dummy process in a manufacturing process of a semiconductor integrated circuit or a semiconductor memory, and in particular, a thin film growth process such as sputtering or a CVD (Chemical Vapor Deposition) method, plasma etching, reactive ion etching, etc. The present invention relates to a dummy wafer suitable for use in dummy processing in various processing steps such as dry etching and plasma cleaning.
[0002]
[Prior art]
Conventionally, in a semiconductor manufacturing process such as a semiconductor integrated circuit and a semiconductor memory, for example, an operation test of various processing apparatuses such as a plasma etching apparatus, a CVD apparatus, and a sputtering apparatus, alignment of the number of wafers during batch processing, and a loading effect countermeasure Therefore, so-called dummy processing is performed in which various processes are performed using a dummy wafer on which no actual IC pattern is formed. Further, when cleaning a reaction chamber of various plasma apparatuses such as a plasma CVD apparatus by plasma cleaning, for example, a dummy wafer is used to protect the substrate holding electrode from plasma.
[0003]
Conventionally, dummy wafers used in semiconductor device manufacturing processes include the following.
(A) Silicon dummy wafer (b) Quartz dummy wafer (c) Ceramic dummy wafer The wafer base is made of ceramics such as alumina or aluminum nitride (d) Glassy carbon dummy wafer wafer base is clear Composed of amorphous carbon that does not show the crystal structure
Moreover, in a semiconductor manufacturing apparatus, it is necessary to fix a wafer to a sample table or the like using a clamp or the like. The main method of fixing the wafer is a mechanical clamp (mechanical clamp). In this case, since a plurality of peripheral portions of the wafer are fixed by the clamp, an unusable region is generated on the surface of the wafer. Therefore, in order to use the wafer surface effectively, a method of fixing the wafer using an electrostatic chuck using electrostatic attraction has begun to be adopted.
[0005]
[Problems to be solved by the invention]
However, the conventional dummy wafer has the following problems.
(A) Silicon dummy wafer The mainstream of conventional dummy wafers is this dummy wafer. Since this silicon wafer is the same as the wafer for manufacturing semiconductor devices and is almost disposable, the amount used is almost the same as the number of wafers for manufacturing actual semiconductor devices. For this reason, about half of the silicon wafers are wasted, which has been a factor in raising the manufacturing cost of semiconductor devices.
[0006]
In addition, when the demand for semiconductor devices increases, the consumption of silicon wafers for manufacturing semiconductor devices and dummy wafers will increase, so the supply of silicon wafers will not be in time, and the supply of polysilicon, which is the raw material, will soon be tight. I was in a situation where I would end up.
Therefore, in order to solve this problem, attempts have been made to develop dummy wafers using materials other than silicon. As a result, dummy wafers of various materials as described in (b) to (d) described above are obtained. It has been put into practical use. However, these dummy wafers have another problem as described below.
[0007]
(B) Quartz dummy wafer Since quartz is an insulating material, a mechanical clamping method is often adopted as its clamping method. In addition, a structure in which a conductor layer is provided on a quartz dummy wafer has been proposed for application to an electrostatic chuck mounting type apparatus. However, the conductor layer is likely to be a source of dust generation and causes metal contamination. There is a problem of becoming.
In addition, a transparent or translucent quartz dummy wafer may not be detected by an optical sensor because it easily transmits light. Therefore, it is necessary to roughen the surface to prevent light transmission or to provide a coating for preventing light transmission.
[0008]
(C) Since the ceramic dummy wafer substrate is made of ceramics such as alumina and aluminum nitride, it is excellent in plasma resistance and chemical resistance, but it is an insulating material as in (b) above. There is a problem that the electrostatic adsorption is weak. Moreover, it may not be detected by the optical sensor, and a light shielding part is necessary. Further, since the specific gravity is larger than that of a silicon wafer, there is a problem that a burden is imposed on the transport system.
(D) It tends to become a glassy carbon dummy wafer dust source.
[0009]
The present invention has been made in view of the above circumstances, is lightweight, has good transportability, has little damage, dust and metal contamination, has a strong electrostatic adsorption force, can be detected by an optical sensor, and is used repeatedly. An object of the present invention is to provide a dummy wafer that can be manufactured at low cost.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, the present invention employs the following dummy wafer.
That is, the dummy wafer of the present invention is characterized in that a conductor layer and a resin film are formed on one main surface or both main surfaces of a plate-like substrate via an adhesive layer.
[0011]
In this dummy wafer, since the resin film is formed on the conductor layer, the distance between the conductor layer and the susceptor is shortened, and a larger electrostatic adsorption force can be obtained.
Further, since the resin film is formed directly on the conductor layer, the total thickness of the laminated portion is reduced, and the thickness of the substrate can be increased accordingly. As a result, the lifetime of the dummy wafer can be extended and the warpage can be reduced.
Further, since the surface of the conductor layer is covered with the resin film, there is no possibility of becoming a dust generation source, and metal contamination is also prevented.
[0012]
It is preferable to form a thin base layer between the conductor layer and the resin film.
Since this thin base layer has a function as a buffer layer, even when there is a difference in thermal expansion coefficient between the conductor layer and the resin film, there is no possibility of peeling or the like.
[0013]
It is preferable that the conductor layer has a smaller area than the base body and an edge portion of the conductor layer is covered with the adhesive layer.
With such a configuration, for example, when used in a sputtering apparatus or the like, there is no possibility that the conductor layer will cause a discharge.
[0014]
The resin film is preferably a heat resistant resin film.
The substrate is preferably made of any one of quartz, glass, ceramics, silicon, and carbon.
The adhesive layer is preferably a thermosetting adhesive or a two-component curable adhesive.
The adhesive layer preferably contains at least one elastomer component.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the dummy wafer of the present invention will be described with reference to the drawings. In addition, the dummy wafer of each embodiment shown below shows an example of the dummy wafer of this invention, and this invention is not limited only to the following embodiment.
[0016]
“First Embodiment”
FIG. 1 is a cross-sectional view showing a dummy wafer according to a first embodiment of the present invention. This dummy wafer has a diameter substantially the same as that of a silicon wafer used in a manufacturing process of a semiconductor integrated circuit or a semiconductor memory, and its weight. Is configured to have substantially the same weight as the silicon wafer.
[0017]
A conductor layer 3 is formed on the surface (one main surface) 1 a of a wafer substrate (plate-shaped substrate) 1 which is a main part of the dummy wafer via an adhesive layer 2. The heat-resistant resin film 4 is directly formed.
The outer diameter of the conductor layer 3 is smaller than the outer diameter of the wafer substrate 1. Therefore, the area of the conductor layer 3 is narrow, and the edge portion is covered with the adhesive layer 2.
[0018]
As a material constituting the wafer substrate 1, quartz, glass, ceramics, silicon, or carbon is preferably used.
As the ceramic, any of alumina, aluminum nitride, silicon nitride, zirconia, mullite, steatite, and silicon carbide is preferably used.
[0019]
The conductor layer 3 is usually made of Cu, Ni, Cr, Al, Ag, Au, Sn, Fe, Pb or the like and having a thickness of 10 μm or less formed by vapor deposition, sputtering, plating, or the like. Alternatively, a conductive layer may be formed by depositing a conductive material or a semiconductor material such as Si using CVD or the like.
[0020]
In order to prevent electric discharge from occurring, the conductor layer 3 is preferably in a state of being enclosed by the adhesive layer 2 so that the edge thereof is not exposed to the outside.
Moreover, after laminating | stacking as a conductor layer on a heat resistant resin film, the method of forming the pattern by an etching is the most preferable.
[0021]
The film thickness of the heat resistant resin film 4 is preferably in the range of 10 to 600 μm, more preferably in the range of 25 to 150 μm. When the film thickness is less than 10 μm, there is a problem in terms of workability, and there is a possibility that scratches due to dust reach the wafer substrate 1. Moreover, when it becomes thicker than 600 micrometers, heat conductivity may worsen, and a malfunction may be produced in a conveyance property because of curvature or the thickness.
Also, when holding the dummy wafer of this embodiment by electrostatic attraction, it is advantageous that the heat-resistant resin film is thin from the viewpoint of securing the attraction force, but in the case of holding by other methods such as mechanical holding Not so.
[0022]
As the heat resistant resin film 4, polyimide film, fluororesin film, silicone resin film, aramid film, polyethylene naphthalate (PEN) film, polyether ether ketone (PEEK) film, polyether sulfone (PES) film, Examples thereof include a polysulfone (PSF) film, a polyetherimide (PEI) film, a polyphenylene sulfide (PPS) film, and a polybenzimidazole (PBI) film.
[0023]
Among these resin films, particularly preferred resin films are a polyimide film and a polyetherimide (PEI) film.
Examples of the polyimide film include Kapton (Kapton: manufactured by DuPont), Apical (manufactured by Kaneka Chemical Co., Ltd.), Upilex (manufactured by Ube Industries), Nitmid (manufactured by Nitto Denki Kogyo Co., Ltd.), and the like.
Examples of the polyetherimide (PEI) film include a superior film (manufactured by Mitsubishi Plastics).
[0024]
In addition to these, examples of the plastic film having a heat resistance of 150 ° C. or higher include stretched polyethylene terephthalate, stretched nylon, cellulose triacetate, and the like. From the use of a dummy wafer, the above-described resin film having better heat resistance is preferred. preferable.
[0025]
The adhesive layer 2 has a dynamic elastic modulus at 25 ° C. of 10 ⁴ MPa or less, and must have excellent adhesion and heat resistance to the wafer substrate 1 and the heat-resistant resin film 4, respectively. A curable adhesive or a two-component curable adhesive is preferred. For example, adhesives such as polyester, polyurethane, polyimide, epoxy, modified polyamide, and rubber are effective, and these adhesives can be used alone or as a mixture. Among these, epoxy adhesives are particularly preferable from the viewpoints of adhesiveness and heat resistance.
[0026]
For this adhesive layer 2, it is effective to use a filler having a particle size of 5 μm or less, such as alumina, zirconium boride, boron nitride, silica, etc., dispersed in a solid content ratio of 5 to 80%. Is. In addition, since adhesiveness falls contrary to the effect of heat conductivity, or metal contamination may occur from the end face, sufficient consideration is required for use.
[0027]
The thickness of the coating film of the adhesive layer 2 is suitably 2 to 40 μm so that the adhesive force can be maintained, and most preferably within the range of 5 to 25 μm from the viewpoint of manufacturing and workability. In some cases, it is effective to increase the thickness of the adhesive layer to reduce the weight of the dummy wafer and the fact that the layer has a stress relaxation function. .
[0028]
Here, an epoxy adhesive that is particularly preferably used will be described with an example.
Although there is no limitation as an epoxy resin, what has two or more epoxy groups in 1 molecule is used suitably. For example, glycidyl ethers, glycidyl esters, glycidyl amines, linear aliphatic epoxides, alicyclic epoxides, and the like.
[0029]
Examples of glycidyl ethers include bisphenol A, bisphenol F, bisphenol AD, bisphenol S, tetramethyl bisphenol A, tetramethyl bisphenol F, tetramethyl bisphenol AD, tetramethyl bisphenol S, tetrachlorobisphenol A, and tetrabromobisphenol A. Diglycidyl ethers of dihydric phenols such as: polyglycidyl ethers of novolac resins such as phenol novolak, cresol novolak, brominated phenol novolak; alkylene glycols such as polyethylene glycol, polypropylene glycol, butanediol, or diglycidyl ethers of polyalkylene glycol Can be given.
[0030]
Examples of glycidyl esters include glycidyl ester of hexahydrophthalic acid and glycidyl ester of dimer acid, and examples of glycidyl amines include triglycidylaminodiphenylmethane, triglycidylaminophenol, triglycidyl isocyanurate, and the like. can give.
Examples of the linear aliphatic epoxide include epoxidized polybutadiene and epoxidized soybean oil. Examples of the alicyclic epoxide include 3,4-epoxy-6-methylcyclohexyl methyl carboxylate, 3,4- Examples thereof include epoxy cyclohexyl methyl carboxylate.
These epoxy resins can be used alone or in combination.
[0031]
Examples of the curing agent for the epoxy resin include bis (4-aminophenyl) sulfone, bis (4-aminophenyl) methane, 1,5-diaminonaphthalene, p-phenylenediamine, m-phenylenediamine, and o-phenylenediamine. , 2,6-dichloro-1,4-benzenediamine, 1,3- (p-aminophenyl) propane, m-xylenediamine and other aromatic amine compounds, ethylenediamine, diethylenetriamine, tetraethylenepentamine, diethylaminopropylamine , Hexamethylenediamine, mensendiamine, isophoronediamine, bis (4-amino-3-methyldicyclohexyl) methane, polymethylenediamine, polyetherdiamine, and other aliphatic amine compounds, polyaminoamide compounds, dodecyl anhydride Acid, aliphatic acid anhydrides such as polyadipic acid anhydride and polyazeline acid anhydride, alicyclic acid anhydrides such as hexahydrophthalic anhydride and methylhexahydrophthalic anhydride, phthalic anhydride, trimellitic anhydride, Mellitic acid triglycerides, benzophenone tetracarboxylic anhydride, aromatic anhydrides such as ethylene glycol bis trimellitate, glycerol tris trimellitate, basic active hydrogen compounds such as dicyandiamide, organic acid dihydrazide, imidazole compounds, Lewis acid And Brested acid salts, polymercaptan compounds, phenol resins, urea resins, melamine resins, isocyanates and blocked isocyanate compounds.
[0032]
In the dummy wafer of this embodiment, the thermal expansion coefficients of the wafer base 1 and the heat-resistant resin film 4 are often different, and two methods are used to prevent the difference in the thermal expansion coefficient from increasing the warpage of the dummy wafer. be able to.
In the first method, the heat resistant resin film 4 is bonded to both surfaces of the wafer substrate 1 and the stress is antagonized, so that the warpage can be reduced as compared with the case where the heat resistant resin film 4 is bonded only to one surface.
[0033]
However, in many cases, the heat-resistant resin film 4 can be bonded only to the back surface for the purpose of each dummy wafer. Therefore, as a second method, the adhesive layer 2 can be obtained by adding an elastomer component to the adhesive. Particularly effective is a method in which the elastic modulus is reduced, the stress due to the difference in thermal expansion between the heat-resistant resin film 4 and the wafer substrate 1 is relieved, and as a result, the warpage of the dummy wafer is reduced.
[0034]
The elastomer component to be added to the adhesive is not particularly specified, but for example, isoprene rubber, butadiene rubber, styrene butadiene rubber, chloroprene rubber, nitrile rubber, butyl rubber, ethylene-propylene rubber, acrylic rubber, silicone rubber, fluoro rubber, urethane Rubbers such as rubber and polysulfide rubber, and thermoplastic elastomers (hereinafter abbreviated as TPE) are styrene TPE, olefin TPE, urethane TPE, ester TPE, amide TPE, natural rubber TPE, poly Mention may be made of vinyl chloride (PVC) TPE.
[0035]
These elastomer components can be used alone or in combination. In addition, as a method of adding to the adhesive, a method in which the elastomer component is liquefied by melting or the like and added to the adhesive, a method in which the elastomer component is compatible with the adhesive in a solid state, or a method in which the elastomer component is refined and added to the adhesive And a method of dispersing it in the adhesive as it is solid.
[0036]
A solvent can be added to the above adhesive as necessary.
Since the dummy wafer is mainly used in a vacuum, there is no particular problem as long as the solvent can be sufficiently removed by drying or the like.
[0037]
The dummy wafer of this embodiment can be manufactured by the following manufacturing method.
First, a metal thin film is formed on the heat resistant resin film 4 by vapor deposition to form the conductor layer 3. Next, the conductor layer 3 is etched to form a conductor layer 3 having a desired pattern. Next, an adhesive film having a peeling tape attached to one surface is opposed to the conductor layer 3, and these are bonded by pressure bonding using a roll laminator or the like.
[0038]
Next, the peeling tape is peeled to expose one surface of the adhesive film, and a roll laminator or a vacuum pressure heating device is used with the exposed surface facing the surface 1a of the wafer substrate 1. Then, the adhesive film is pressure-bonded to the surface 1a of the wafer substrate 1, and the two are bonded together to obtain a dummy wafer of this embodiment.
[0039]
According to the dummy wafer of the present embodiment, the conductor layer 3 is formed on the surface 1a of the wafer substrate 1 via the adhesive layer 2, and the heat-resistant resin film 4 is formed directly on the conductor layer 3. The distance between the surface of the electrostatic chuck and the conductor layer can be shortened compared with the case where the adhesive layer is interposed, and a larger electrostatic adsorption force can be obtained.
[0040]
Further, since the thin conductor layer 3 can be formed by not using an adhesive layer and by sputtering or the like, the total film thickness of the laminated portion other than the wafer substrate 1 can be reduced. Accordingly, the thickness of the wafer base 1 can be increased accordingly, and the life of the wafer can be extended, and the warpage due to the relatively thick wafer base 1 can be reduced.
[0041]
Furthermore, since the conductor layer 3 can be made thin, a step between the adhesive layer 2 and the end face of the conductor layer 3 is hardly generated. If a step is generated, a void or the like may be generated, which is not preferable for a dummy wafer used in a vacuum.
[0042]
Moreover, it is excellent in terms of productivity and cost as compared with the case where the conductor layer is formed directly on the wafer. For example, when forming a conductor layer on the wafer side, considering the use in a semiconductor process equipment, etc., the process of cutting, polishing, etc. is completed, and one or several batches of products finished in wafer shape in advance Since it is necessary to form a conductor layer by treatment, productivity is not good.
[0043]
On the other hand, in the case of a heat-resistant resin film such as a polyimide film, it is easy to continuously form a conductor layer, and there is an advantage that a patterning process by etching or the like can be performed by continuous processing. Further, the conductor layer forming process and the patterning process are not necessarily 100% productable. In this case, even if there is a slight difference in yield between an expensive wafer and a relatively inexpensive film, the present embodiment The cost advantage of the dummy wafer is obvious.
[0044]
“Second Embodiment”
FIG. 2 is a cross-sectional view showing a dummy wafer according to the second embodiment of the present invention. This dummy wafer is different from the dummy wafer according to the first embodiment described above in the first embodiment described above. In the dummy wafer, the heat-resistant resin film 4 is formed directly on the conductor layer 3, whereas in the dummy wafer of this embodiment, a thin base layer is provided between the conductor layer 3 and the heat-resistant resin film 4. 5 is formed.
Ni, Cr, Sn or the like is preferably used as the material constituting the underlayer 5. The thickness of the underlayer 5 is preferably 5 μm or less, and it is preferable that the thickness variation in the surface direction is small.
The underlayer 5 can be formed by vapor deposition, sputtering, plating, or the like.
[0045]
The dummy wafer of this embodiment is manufactured by the following manufacturing method.
First, a metal thin film is formed on the heat resistant resin film 4 by vapor deposition or sputtering to form an underlayer 5. Next, a metal thin film is formed on the base layer 5 by sputtering or plating to form the conductor layer 3. Next, the foundation layer 5 and the conductor layer 3 are etched to form the foundation layer 5 and the conductor layer 3 having a desired pattern. Next, an adhesive film having a peeling tape attached to one surface is opposed to the conductor layer 3, and these are bonded by pressure bonding using a roll laminator or the like.
[0046]
Next, the peeling tape is peeled to expose one surface of the adhesive film, and a roll laminator or a vacuum pressure heating device is used with the exposed surface facing the surface 1a of the wafer substrate 1. Then, the adhesive film is pressure-bonded to the surface 1a of the wafer substrate 1, and the two are bonded together to obtain a dummy wafer of this embodiment.
[0047]
Also in the dummy wafer of this embodiment, the same effect as the dummy wafer of the first embodiment described above can be obtained.
Moreover, since the thin base layer 5 is formed between the conductor layer 3 and the heat resistant resin film 4, the base layer 5 has a function as a buffer layer, so that the conductor layer 3 and the heat resistant resin film are provided. Even when there is a difference in the coefficient of thermal expansion from 4, there is no possibility of peeling or the like.
[0048]
【Example】
Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. In addition, since the Example shown below shows an example of this invention, this invention is not limited by these Examples.
"Creating an adhesive"
In preparing the examples and comparative examples, the following three types of adhesives were prepared in advance. These were used in the respective Examples and Comparative Examples, but the composition was not changed except for the addition of a solvent for adjusting the viscosity depending on the coating method.
[0049]
(Adhesive A)
Epoxy resin (Epicoat YL979, manufactured by Yuka Shell Co., Ltd.) 50 parts Cresol type phenolic resin (CKM2400, manufactured by Showa Polymer Co., Ltd.) 50 parts Acrylonitrile-butadiene rubber (Nippol 1001, manufactured by Nippon Zeon Co., Ltd.) 50 parts Dicyandiamide (Wako Pure Chemical Industries, Ltd.) 2 parts methyl ethyl ketone as appropriate]
(Adhesive B)
Epoxy resin (Epicoat YL979, manufactured by Yuka Shell Co., Ltd.) 100 parts Polyamide resin (Platabonda M-995, manufactured by Nippon Rilsan Co., Ltd.) 200 parts Novolak phenol resin (Tamanol 752, manufactured by Arakawa Chemical Co., Ltd.) 50 parts Dicyandiamide (Wako Pure Chemical Industries, Ltd.) ) 0.25 part methyl ethyl ketone as appropriate
(Adhesive C)
Epoxy resin (Epicoat YL979, manufactured by Yuka Shell Co., Ltd.) 100 parts One-end epoxy-modified silicone oil (X-22-173B, manufactured by Shin-Etsu Chemical Co., Ltd.) 18 parts Novolac phenol resin (Tamanol 752, manufactured by Arakawa Chemical Co., Ltd.) 50 parts Dicyandiamide (Manufactured by Wako Pure Chemical Industries, Ltd.) 0.5 part carbon black powder (manufactured by Mitsubishi Chemical Corporation) 0.2 part methyl ethyl ketone As appropriate [0052]
"Example 1"
A 1 μm thick Ni layer was formed by sputtering on a 25 μm thick polyimide film (trade name Kapton, manufactured by Toray DuPont), and a 9 μm thick Cu layer was formed by plating. A negative photosensitive film (OZATEC-T538, manufactured by Hoechst Japan) was bonded to the Cu layer side, and an electrode pattern of φ146 mm was formed by sequentially performing exposure-development-etching-washing-drying.
[0053]
Next, an adhesive A having a thickness of 20 μm, which has been coated and dried on a binder in advance and formed into a sheet, is bonded to the electrode pattern surface, and then the Cu layer pattern is centered on alumina having a diameter of 150 μm and a thickness of 600 μm. And aligned. Then, it heated at 150 degreeC for 4 hours in hot air oven, and obtained the dummy wafer with a polyimide film of Example 1.
[0054]
"Example 2"
In the same manner as in Example 1, a Ni layer having a thickness of 1 μm was formed by sputtering on an aramid film having a thickness of 25 μm (trade name: Aramika, manufactured by Asahi Kasei Co., Ltd.). The Ni layer was formed. Next, a negative photosensitive film (OZATEC-T538, manufactured by Hoechst Japan) was bonded to the Ni layer side, and an electrode pattern of φ146 mm was formed by sequentially performing exposure-development-etching-washing-drying.
[0055]
Next, an adhesive C having a thickness of 20 μm, which has been coated and dried on a binder in advance and formed into a sheet, is pasted on the electrode pattern surface, and then the Ni layer pattern is centered on a quartz plate having a diameter of 150 mm and a thickness of 600 μm. Were aligned and pasted together. Then, it heated at 150 degreeC for 4 hours in hot air oven, and obtained the dummy wafer of Example 2.
[0056]
"Example 3"
An Al layer having a thickness of 5 μm was formed on one side of a polyether ether ketone film having a thickness of 25 μm (trade name Sumilite FS, manufactured by Sumitomo Bakelite Co., Ltd.). Next, a negative photosensitive film (OZATEC-T538, manufactured by Hoechst Japan) was bonded to this surface, and an electrode pattern of φ146 mm was formed by sequentially performing exposure-development-etching-washing-drying.
[0057]
Next, an adhesive B having a thickness of 100 μm, which has been coated and dried on a binder in advance to form a sheet, is bonded to the electrode pattern surface, and then the Ni layer pattern is centered on a SiC plate having a diameter of 150 μm and a thickness of 400 μm. Aligned and pasted together. Then, it heated at 150 degreeC for 4 hours in hot air oven, and obtained the dummy wafer of Example 3.
[0058]
“Comparative Example 1”
A quartz wafer having a diameter of 150 mm and a thickness of 600 μm was used as Comparative Example 1.
"Comparative Example 2"
A 25 μm thick polyester film (trade name: Teijin Tetron Film, manufactured by Teijin Ltd.) is coated with adhesive A using a coating device, and dried at 170 ° C. with a drying device attached to the coating device. A polyester film with an adhesive having a thickness of 20 μm was prepared. Subsequently, this polyester film with an adhesive was bonded to a quartz wafer having a diameter of 150 mm and a thickness of 600 μm using a roll laminator and heated in a hot air oven at 150 ° C. for 4 hours to obtain a dummy wafer of Comparative Example 2.
[0059]
“Comparative Example 3”
A Ni film having a thickness of 2 μm was formed by sputtering on one side and the whole surface of a SiC plate having a diameter of 150 mm and a thickness of 600 μm, and Comparative Example 3 was obtained.
“Comparative Example 4”
A Ni film having a thickness of 2 μm was formed by sputtering on one side and the entire surface of an alumina plate having a diameter of 150 mm and a thickness of 600 μm, and the adhesive surface of the polyester film with an adhesive obtained in Comparative Example 2 was formed on the surface of the Ni film. Were laminated using a roll laminator and heated in a hot air oven at 150 ° C. for 4 hours to obtain a dummy wafer of Comparative Example 4.
[0060]
The dummy wafers of Examples 1 to 3 and Comparative Examples 1 to 4 thus obtained were subjected to evaluation tests for the following evaluation items.
(1) Place a dummy wafer on an electrostatic chuck (dipole, electrode area 50 mm x 50 mm) with a high resistance ceramic on the surface, and pull the dummy wafer in a horizontal direction at a constant speed (20 mm / 1 min) A dummy wafer was adsorbed by applying a DC voltage of 2.5 kV to the electric chuck. At this time, a value obtained by dividing the force applied in the horizontal direction by the electrode area was defined as a shear adsorption force.
[0061]
(2) Decrease in adsorption force when dust is contained Twenty 20 μm spherical silica particles are adhered near the center of the back side of the dummy wafer, and the shear adsorption force at the time of dust adhesion is measured in the same manner as in (1). The influence of the reduction in the adsorption force due to dust was evaluated by obtaining the adsorption force at the time of dust adhesion when the initial adsorption force in the absence of dust was taken as 100.
[0062]
(3) Scratches The operations of placing, pressing and releasing the dummy wafers prepared in Examples 1 to 3 and Comparative Examples 1 to 4 on a mechanical chuck device having alumina on the suction surface were repeated 100 times. Then, the dummy wafer back surface and the mechanical chuck | zipper surface of each Example 1-3 and Comparative Examples 1-4 were observed, and the condition of generation | occurrence | production of a damage | wound was observed.
Here, “◯” indicates that no scratches are observed, and “X” indicates that scratches are observed even a little.
[0063]
(4) Sensor recognizability The position of the dummy wafer created in Examples 1 to 3 and Comparative Examples 1 to 4 is detected with a laser using a transfer device equipped with a laser position detection sensor, and the process proceeds to the next operation. The operation was repeated 20 times, and the sensor recognizability was evaluated by the presence or absence of a detection error.
Here, “◯” indicates that the position was detected without any problem after 50 operations, and “X” indicates that a position detection error occurred even once.
[0064]
(5) Transportability The dummy wafer created in Examples 1 to 3 and Comparative Examples 1 to 4 is taken out from the wafer cassette using the transport device, and placed in a predetermined position 50 times. The case where it was able to be installed at “” was marked as “X” when it could not be installed at a predetermined position even once.
[0065]
(6) Heat resistance The dummy wafer prepared in Examples 1 to 3 and Comparative Examples 1 to 4 is placed on a sample stage in a vacuum vessel and mechanically pressed with a frame-shaped ring to fix the dummy wafer. did. Thereafter, the inside of the vacuum vessel was depressurized to 2.0 Pa by a dry pump, and left for 20 hours while being heated so that the temperature of the dummy wafer surface was 150 ° C. by a heater installed in the sample stage. Thereafter, the temperature was returned to room temperature and atmospheric pressure, and the conditions such as peeling, voids, and alteration of the dummy wafer and the heat resistant film, the adhesive layer, and the conductor layer were observed. Here, the case where no abnormality was found was “◯”, and the case where abnormality was found was “x”.
[0066]
(7) Metal contamination contamination was evaluated by preparing an evaluation sample by the following simulation.
A 10 mm × 10 mm cleaned 99.99% pure alumina plate was placed on the back of the dummy wafers created in Examples 1 to 3 and Comparative Examples 1 to 4, and pressed with a load of 1.0 kg from above. . Thereafter, the load was released, the alumina plate was removed, and the alumina plate was placed again to apply the load. After this operation was repeated 20 times, the degree of metal contamination was measured by the contamination EDX method on the ceramic surface.
[0067]
The above evaluation test results are shown in Table 1.
[Table 1]

[0068]
The dummy wafers of Examples 1 to 3 have a shear adsorption force of 0.03 N / cm ² and a decrease in adsorption force of 92 or more when entrained with dust. It is confirmed that the shear adsorption force when dust adheres is extremely excellent. It was. Further, no scratches were observed, and it was found that the damage was extremely small. In addition, regarding sensor recognizability, no detection error was observed, and it was found that detection by the optical sensor was performed well.
[0069]
Further, regarding the transportability, it was found that there was nothing that could not be installed at a predetermined position, and the transportability was improved. As for heat resistance, no abnormality was observed, and it was confirmed that the film was in a very good state. There was no problem with metal contamination.
[0070]
On the other hand, in Comparative Example 1, although there were no problems in terms of transportability, heat resistance, and metal contamination, the shear adsorption force was 0.01 N / cm ² , and the decrease in adsorption force when dust was trapped was greatly reduced to 48. It was also found that the shear adsorption force when dust adhered was inferior. Moreover, generation | occurrence | production of a damage | wound was recognized and the detection error about the sensor recognizability also generate | occur | produced and it turned out that the detection by an optical sensor is not performed favorably.
Comparative Example 2 has a shear adsorption force of 0.01 N / cm ² and a reduction in adsorption force of 93 when dust is contained. There were no problems with scratches, transportability, and metal contamination, but sensor recognizability and heat resistance were good. It was confirmed that it was inferior.
[0071]
In Comparative Example 3, the shear adsorption force was as extremely high as 0.06 N / cm ² and there was no problem with respect to heat resistance, but the decrease in adsorption force during dust entrapment was as low as 42, and generation of scratches was recognized. The heat resistance and the heat resistance were also poor, and Ni was detected in metal contamination.
Comparative Example 4 has a shear adsorption force of 0.02 N / cm ² and a reduction in adsorption force of 95 when dust is contained, and there are no problems with respect to scratches, sensor recognizability, transportability, and metal contamination. It was confirmed that it was inferior.
[0072]
As mentioned above, although each embodiment of the dummy wafer of this invention has been demonstrated based on drawing, a concrete structure is not limited to this embodiment, A design change etc. are in the range which does not deviate from the summary of this invention. Is possible.
For example, the dummy wafer according to the present embodiment is configured to have substantially the same diameter as the silicon wafer used in the semiconductor manufacturing process, and the weight of the dummy wafer is approximately the same as that of the silicon wafer. There is no need to make it exactly the same as a silicon wafer.
[0073]
【The invention's effect】
As described above, according to the dummy wafer of the present invention, the conductor layer and the resin film are formed on one main surface or both main surfaces of the plate-like substrate via the adhesive layer. The distance between the conductor layer and the susceptor can be shortened, and a larger electrostatic adsorption force can be obtained.
In addition, since the conductor layer is formed directly on the resin film, the total thickness of the laminated part can be reduced, and the thickness of the substrate itself can be increased correspondingly, resulting in a long life of the dummy wafer. And reduction of warpage can be achieved.
Further, since the surface of the conductor layer is covered with the resin film, there is no possibility of becoming a dust generation source, and metal contamination can be prevented.
[0074]
Further, if a thin base layer is formed between the conductor layer and the resin film, even if there is a difference in thermal expansion coefficient between the conductor layer and the resin film, peeling or the like is performed. Can be prevented.
In addition, if the conductor layer has a smaller area than the base body and its edge is covered with the adhesive layer, the conductor layer can be discharged when used in a sputtering apparatus or the like. Can be prevented.
The above provides a dummy wafer that is lightweight, has good transportability, has little damage, dust and metal contamination, has strong electrostatic attraction, can be detected by an optical sensor, can be used repeatedly, and is inexpensive. can do.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a dummy wafer according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a dummy wafer according to a second embodiment of the present invention.
[Explanation of symbols]
1 Wafer base (plate base)
1a Surface (one main surface)
2 Adhesive layer 3 Conductor layer 4 Heat resistant resin film 5 Base layer

Claims (4)

An adhesive layer made of a thermosetting adhesive or a two-component curable adhesive is provided on one or both main surfaces of a plate-like substrate made of any one of quartz, glass, ceramics, silicon, and carbon. A dummy wafer in which a conductor layer is formed, and a heat-resistant resin film is directly formed on the conductor layer .   The dummy wafer according to claim 1, wherein a thin base layer is formed between the conductor layer and the resin film.   The dummy wafer according to claim 1, wherein the conductor layer has a smaller area than the base body, and an edge portion of the conductor layer is covered with the adhesive layer. The adhesive layer according to claim 1 to any one of claims dummy wafers 3, characterized by comprising the elastomer component contains at least one kind.

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