JP2004018332A - Method for manufacturing silicon tetrafluoride - Google Patents
Method for manufacturing silicon tetrafluoride Download PDFInfo
- Publication number
- JP2004018332A JP2004018332A JP2002177850A JP2002177850A JP2004018332A JP 2004018332 A JP2004018332 A JP 2004018332A JP 2002177850 A JP2002177850 A JP 2002177850A JP 2002177850 A JP2002177850 A JP 2002177850A JP 2004018332 A JP2004018332 A JP 2004018332A
- Authority
- JP
- Japan
- Prior art keywords
- silicon
- silicon tetrafluoride
- gas
- arsenic
- phosphorus
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Abstract
Description
【0001】
【発明の属する技術分野】
本発明は、エレクトロニクス分野、光学分野等で使用される高純度四フッ化珪素の製造法に関するものである。
【0002】
【従来の技術および発明が解決しようとする課題】
四フッ化珪素(SiF4)は、石英系ファイバーのフッ素ドープ剤、半導体リソグラフィー用フォトマスク材料の原料、半導体製造用CVD原料ガスなどに利用されその使用量は年々増加している。これら用途に使用される四フッ化珪素は、非常に純度の高いものが求められているが、中でもリンおよびヒ素成分はごく微量であっても悪影響があるため、この両元素に対する純度要求は特に厳しい。このためリン、ヒ素成分含有量の低い四フッ化珪素を効率よく製造する技術が求められている。
【0003】
リン、ヒ素を含まない四フッ化珪素を得ようとすればリン、ヒ素を含有しない高純度の珪素およびフッ化水素原料を使用すればよいが、かかる原料は高価であり製造コストの面で不利である。そのため純度の低い廉価な原料を使用するときには原料に由来する不純物を反応ガスから精製除去する必要がある。
【0004】
また、式(1)は、珪素とフッ化水素ガスとの反応によって四フッ化珪素を製造する反応である。
【0005】
Si(固体)+4HF(気体) → SiF4(気体)+2H2(気体)(1)
当該反応において、原料の珪素に含まれる不純物であるリン、ヒ素がフッ素化されてPF3(bp.=−101.1℃),PF5(bp.=−84.6℃),AsF5(bp.=−52.9℃)等の蒸気圧を有する化合物が形成され、あるいはもう一方の原料であるフッ化水素に含まれている同様な化合物が、四フッ化珪素生成ガス(式(1)の右辺に相当するSiF4とH2との体積比が1対2の混合ガス)中に混入してくるために高純度のものを得るのが困難な状態であった。
【0006】
【課題を解決するための手段】
本発明者らは、純度の低い珪素およびフッ化水素を原料とする式(1)に示す四フッ化珪素の反応を詳細に検討した結果、該反応で生成した四フッ化珪素ガスに混入してくるリン、ヒ素化合物は、該四フッ化珪素ガスを300℃以上に加熱した珪素で処理することによってガス側から除くことができることを見出し本発明に到達した。
【0007】
すなわち本発明は、珪素とフッ化水素との反応で生成した四フッ化珪素ガス中に含有するリン、ヒ素を除去するため該四フッ化珪素ガスを珪素と接触させるに際し、300〜800℃の範囲で、(V/Q)≧kの条件で珪素と該四フッ化珪素ガスを接触させること特徴とする四フッ化珪素の製造方法(ただし、Vは、珪素を充填した部分の容器の容積[リットル]を、Qは、該四フッ化珪素ガス生成ガスの流量[Nリットル/分]を、kは、k=18/(d−291)+0.04で定義され、dは、温度[℃]をそれぞれ表す。)を提供するものである。
【0008】
本発明において、精製領域における必要とする条件について述べる。加熱した珪素を充填した領域の容積をV[リットル](Vは容器の空塔容積とする)、リン、ヒ素を精製しようとする四フッ化珪素生成ガスの流量をQ[Nリットル/分]、精製領域の温度をd[℃]としたとき、V/Q≧kなる条件で該四フッ化珪素生成ガスと珪素を接触させなければならない。ただしkは、k=18/(d−291)+0.04で定義される。そのため300℃においては、V/Q≧2.04、400℃においては、V/Q≧0.21、600℃においては、V/Q≧0.10となる。そのため設定温度においてのk値より小さくなるようなV値とQ値を選択すると、リン、ヒ素の不純物が除去できなくなる。
【0009】
本発明において、精製に使用する珪素は、四フッ化珪素を製造するための原料と同一のものを使用すればよく、必ずしも高純度のものを必要とするわけではない。例えば、ポリシリコンの原料として工業的に多量に流通している、珪砂を炭素で還元して製造される純度95〜99%程度の珪素でも十分である。これら低純度の珪素には、精製しようとしている元素であるリンやヒ素が含まれており、一見精製剤としては、不適当であるように思われるかもしれないが、本製造法においては、珪素中に含まれているリンやヒ素がガス化し生成した四フッ化珪素ガス中のこれらの濃度が高くなることはない。またリンやヒ素以外の不純物についても同様に四フッ化珪素ガスを汚染することはない。生成した四フッ化珪素ガスは、体積でその約66%が水素であり、この水素と加熱した珪素の作用により、リンとヒ素が蒸気圧の低い化合物となって平衡的に固相側に偏るものと解釈されるが、リン、ヒ素の存在量がppbレベルとあまりに微少であるためその機構の詳細は解明できていない。
【0010】
さらに、リン、ヒ素の精製にあたって留意すべきは、フッ化水素の存在が精製効率を著しく低下させるという点である。この理由は、フッ化水素が、リン、ヒ素のフッ素化剤として作用するために上述した平衡が逆に移行し精製の目的と反対の現象が起きるためと考えれば理解できる。このため、精製工程においては生成した四フッ化珪素ガス中からできるだけフッ化水素を除外しておく必要がある。
【0011】
ここで本発明においては、加熱した珪素によるリン、ヒ素の精製法は、この点で特に有利なものであるということができる。なぜなら、リン、ヒ素の精製剤として作用する珪素は、同時に妨害成分であるフッ化水素とも反応してこれを消去し、しかもその結果発生するものは四フッ化珪素と水素のみであってメインのフローである四フッ化珪素の製造になんら影響を及ぼさないからである。
【0012】
生成した四フッ化珪素ガスを加熱した珪素で処理してリン、ヒ素を除去するための装置としては、ヒーターを備えた一般的な充填塔などを使用することができ、当該装置を独立した精製装置として主反応の反応器の後段に設置するのは本発明の一つの実施態様である。さらにまた主反応である珪素とフッ化水素との反応も同様な型式の反応器を利用することができるので、これら一連の操作を設備的に簡略化する目的で主反応およびリン、ヒ素の精製を一基の容器の中で連続して行うこともできる。つまり珪素を充填した反応容器の一方から原料のフッ化水素ガスを供給し気相がバックミキシングを起こさないいわゆるピストンフロー方式で流通させ他端から排出することで、容器の上流側部分が主反応領域、下流側部分がリン、ヒ素の精製領域として作用するのである。
【0013】
式(1)に示す主反応は、室温ではほとんど進行せず温度を上げると250℃付近から反応速度が急に大きくなり、特に温度的な上限はない。一方、300℃以下では、リンやヒ素はほとんど除去されないので必要下限温度は、リン、ヒ素の精製の方が若干高いがこちらもまた特に温度上限はない。そこで、主反応と精製を同一容器で行なおうとするときは、主反応部と精製部に温度分布をつける等の複雑な構造とする必要はなく、両工程で必要な高い方の温度設定に合わせればよい。また両工程とも温度が高いほど反応速度が速いので、珪素の融点(1420℃)までの範囲でなるべく高温で実施するのが効率面では有利であるが、反応器材料に汎用金属が使用できる800℃以下で実施するのが工業的応用としては有利である。実用的には400℃〜600℃で十分な反応速度を示すこの温度範囲が最適である。
【0014】
また、本発明の方法によってリン、ヒ素を除かれた四フッ化珪素ガスは、次いで四フッ化珪素と水素の蒸気圧差を利用する等の通常の分離法を応用して水素を除き純粋な四フッ化珪素を得ることができる。
【0015】
【実施例】
以下、本発明を実施例をもって詳細に説明する。
【0016】
比較例1〜5、実施例1〜5
珪砂の炭素還元法で製造した純度98%の粒子状珪素(粒径5mmφから15mmφの破砕物)を計量して円筒縦型の容器に仕込んだ。容器は、内径80mmφ、高さ500mmのNi製で、天板にはガスを供給するノズルと温度計のスタンドを、底板にはガスを排出するノズルを備えている。容器外周には、電気ヒーターを配しており内部を所定の温度に保つことができる仕様になっている。
【0017】
天板ノズルから、四フッ化珪素=33vol%、P=550wtppb、As=46wtppb、残部が水素からなるガスを0.2Nリットル/分〜4.4Nリットル/分の流量で供給し、Si充填部をピストンフロー方式で上から下方に通過しながらほぼ大気圧にて流通させた。温度条件250〜600℃で珪素と接触させた。下部ノズルから排出したガスを純水に吸収させ、リンについてはイオンクロマトグラフィーで、ヒ素についてはICP−MSで分析した。それらの結果と実験条件を表1に示した。
【0018】
実施例6〜7
天板ノズルから供給するガスが、フッ化水素を1000volppm追加して含む組成である以外は実施例1および実施例3と同様の方法で処理した。それぞれ実施例6、実施例7として結果を表1に示した。またこれら出口ガスはFT−IRで分析しフッ化水素が存在していない(20volppm以下)ことを確認した。
【0019】
【表1】
【0020】
【発明の効果】
本発明により、低純度SiとHFとの反応で、エレクトロニクス分野用途グレードの高純度SiF4を安価に製造することが可能となった。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing high-purity silicon tetrafluoride used in the fields of electronics, optics, and the like.
[0002]
2. Description of the Related Art
Silicon tetrafluoride (SiF 4 ) is used as a fluorine dopant for quartz fibers, a raw material for a photomask material for semiconductor lithography, a CVD raw material gas for semiconductor production, and the like, and its usage is increasing year by year. The silicon tetrafluoride used for these applications is required to have a very high purity, but the phosphorus and arsenic components are harmful even in a very small amount. Strict. Therefore, there is a need for a technique for efficiently producing silicon tetrafluoride having a low phosphorus and arsenic component content.
[0003]
To obtain phosphorus and arsenic-free silicon tetrafluoride, high-purity phosphorus and arsenic-free silicon and hydrogen fluoride raw materials may be used, but such raw materials are expensive and disadvantageous in terms of production cost. It is. Therefore, when an inexpensive raw material with low purity is used, it is necessary to purify and remove impurities derived from the raw material from the reaction gas.
[0004]
Equation (1) is a reaction for producing silicon tetrafluoride by a reaction between silicon and hydrogen fluoride gas.
[0005]
Si (solid) + 4HF (gas) → SiF 4 (gas) + 2H 2 (gas) (1)
In this reaction, phosphorus and arsenic, which are impurities contained in silicon as a raw material, are fluorinated and PF 3 (bp. = − 101.1 ° C.), PF 5 (bp. = − 84.6 ° C.), AsF 5 ( bp. =-52.9 ° C.), or a similar compound contained in the other material, hydrogen fluoride, is converted to a silicon tetrafluoride producing gas (formula (1) ), The volume ratio of SiF 4 and H 2 corresponding to the right side of (1) is mixed into the mixed gas having a ratio of 1: 2), so that it was difficult to obtain a high-purity product.
[0006]
[Means for Solving the Problems]
The present inventors have studied in detail the reaction of silicon tetrafluoride represented by the formula (1) using low-purity silicon and hydrogen fluoride as raw materials. The inventors have found that the coming phosphorus and arsenic compounds can be removed from the gas side by treating the silicon tetrafluoride gas with silicon heated to 300 ° C. or higher.
[0007]
That is, the present invention provides a method for removing phosphorus and arsenic contained in a silicon tetrafluoride gas generated by a reaction between silicon and hydrogen fluoride, when the silicon tetrafluoride gas is brought into contact with silicon to remove 300 to 800 ° C. A method for producing silicon tetrafluoride, wherein silicon and the silicon tetrafluoride gas are brought into contact with each other under the condition of (V / Q) ≧ k (where V is the volume of a vessel filled with silicon) [Liter], Q is the flow rate of the silicon tetrafluoride gas generating gas [N liter / min], k is defined as k = 18 / (d-291) +0.04, and d is the temperature [ ° C].).
[0008]
In the present invention, conditions required in the purification region will be described. The volume of the region filled with the heated silicon is V [liter] (V is the empty space volume of the container), and the flow rate of the silicon tetrafluoride producing gas for purifying phosphorus and arsenic is Q [N liter / min]. When the temperature of the purification region is d [° C.], the silicon tetrafluoride-producing gas must be brought into contact with silicon under the condition of V / Q ≧ k. Here, k is defined as k = 18 / (d-291) +0.04. Therefore, at 300 ° C., V / Q ≧ 2.04, at 400 ° C., V / Q ≧ 0.21, and at 600 ° C., V / Q ≧ 0.10. Therefore, if a V value and a Q value that are smaller than the k value at the set temperature are selected, the phosphorus and arsenic impurities cannot be removed.
[0009]
In the present invention, the same silicon as the raw material for producing silicon tetrafluoride may be used as the silicon used for the purification, and high-purity silicon is not necessarily required. For example, silicon having a purity of about 95 to 99% produced by reducing silica sand with carbon, which is industrially distributed in large quantities as a raw material for polysilicon, is sufficient. These low-purity silicon contain phosphorus and arsenic, which are the elements to be purified, and may seem seemingly unsuitable as a purifying agent. The concentration of these in the silicon tetrafluoride gas generated by gasification of phosphorus and arsenic contained therein does not increase. Similarly, impurities other than phosphorus and arsenic do not contaminate the silicon tetrafluoride gas. Approximately 66% by volume of the generated silicon tetrafluoride gas is hydrogen. By the action of this hydrogen and heated silicon, phosphorus and arsenic become compounds having a low vapor pressure and are equilibrium shifted toward the solid phase. However, since the abundances of phosphorus and arsenic are too small at the ppb level, the details of the mechanism have not been elucidated.
[0010]
Furthermore, it should be noted that the purification of phosphorus and arsenic significantly reduces the purification efficiency due to the presence of hydrogen fluoride. The reason for this can be understood from the assumption that hydrogen fluoride acts as a fluorinating agent for phosphorus and arsenic, so that the above-mentioned equilibrium shifts in the opposite direction and a phenomenon opposite to the purpose of purification occurs. For this reason, in the purification process, it is necessary to remove hydrogen fluoride as much as possible from the generated silicon tetrafluoride gas.
[0011]
Here, in the present invention, the method for purifying phosphorus and arsenic using heated silicon can be said to be particularly advantageous in this regard. This is because silicon, which acts as a purifier for phosphorus and arsenic, also reacts with hydrogen fluoride, an interfering component, to eliminate it, and only silicon tetrafluoride and hydrogen are generated as a result, resulting in the main component. This is because it has no influence on the production of silicon tetrafluoride as a flow.
[0012]
As a device for treating the generated silicon tetrafluoride gas with heated silicon to remove phosphorus and arsenic, a general packed tower equipped with a heater can be used. It is one embodiment of the present invention that the apparatus is installed downstream of the main reaction reactor. In addition, since the same type of reactor can be used for the reaction between silicon and hydrogen fluoride, which is the main reaction, the main reaction and the purification of phosphorus and arsenic are performed in order to simplify the series of operations in equipment. Can be continuously performed in a single container. In other words, by supplying hydrogen fluoride gas as a raw material from one side of a reaction vessel filled with silicon, flowing the gas phase in a so-called piston flow method in which back mixing does not occur, and discharging the gas from the other end, the upstream side portion of the vessel performs the main reaction. The region and the downstream portion act as a phosphorus and arsenic purification region.
[0013]
The main reaction shown in the formula (1) hardly progresses at room temperature, and when the temperature is increased, the reaction rate rapidly increases from around 250 ° C., and there is no particular upper limit in temperature. On the other hand, when the temperature is 300 ° C. or lower, phosphorus and arsenic are hardly removed, so that the required lower limit temperature is slightly higher in the case of purifying phosphorus and arsenic, but also there is no particular upper limit. Therefore, when the main reaction and purification are to be performed in the same vessel, there is no need to use a complicated structure such as providing a temperature distribution in the main reaction section and the purification section. Just match. In both processes, the higher the temperature, the higher the reaction rate. Therefore, it is advantageous in terms of efficiency to carry out the reaction at a temperature as high as possible up to the melting point of silicon (1420 ° C.). It is advantageous to carry out at a temperature of not more than ℃ for industrial applications. Practically, this temperature range that shows a sufficient reaction rate at 400 ° C. to 600 ° C. is optimal.
[0014]
In addition, the silicon tetrafluoride gas from which phosphorus and arsenic have been removed by the method of the present invention is then purified by a conventional separation method such as utilizing the vapor pressure difference between silicon tetrafluoride and hydrogen to remove pure hydrogen. Silicon fluoride can be obtained.
[0015]
【Example】
Hereinafter, the present invention will be described in detail with reference to examples.
[0016]
Comparative Examples 1 to 5, Examples 1 to 5
Particulate silicon having a purity of 98% (crushed product having a particle size of 5 mmφ to 15 mmφ) produced by the carbon reduction method of silica sand was weighed and charged in a cylindrical vertical container. The container is made of Ni having an inner diameter of 80 mmφ and a height of 500 mm. The top plate has a nozzle for supplying gas and a thermometer stand, and the bottom plate has a nozzle for discharging gas. An electric heater is arranged on the outer periphery of the container so that the inside can be maintained at a predetermined temperature.
[0017]
From the top plate nozzle, a gas composed of silicon tetrafluoride = 33 vol%, P = 550 wtppb, As = 46 wtppb, and the balance hydrogen is supplied at a flow rate of 0.2 Nl / min to 4.4 Nl / min, and the Si filling portion is provided. While flowing from above to below in a piston flow system, was flowed at almost atmospheric pressure. It was brought into contact with silicon at a temperature condition of 250 to 600 ° C. The gas discharged from the lower nozzle was absorbed in pure water, and phosphorus was analyzed by ion chromatography, and arsenic was analyzed by ICP-MS. Table 1 shows the results and the experimental conditions.
[0018]
Examples 6 and 7
The processing was performed in the same manner as in Examples 1 and 3, except that the gas supplied from the top plate nozzle had a composition containing 1000 vol ppm of hydrogen fluoride. The results are shown in Table 1 as Example 6 and Example 7, respectively. These outlet gases were analyzed by FT-IR, and it was confirmed that hydrogen fluoride was not present (20 vol ppm or less).
[0019]
[Table 1]
[0020]
【The invention's effect】
According to the present invention, it has become possible to produce high-purity SiF 4 of a grade for use in the electronics field at low cost by the reaction between low-purity Si and HF.
Claims (1)
ただし、Vは、珪素を充填した部分の容器の容積[リットル]を、
Qは、該四フッ化珪素ガス生成ガスの流量[Nリットル/分]を、
kは、k=18/(d−291)+0.04で定義され、
dは、温度[℃]をそれぞれ表す。When the silicon tetrafluoride gas is contacted with silicon to remove phosphorus and arsenic contained in the silicon tetrafluoride gas generated by the reaction between silicon and hydrogen fluoride, (V) / Q) A method for producing silicon tetrafluoride, comprising bringing silicon into contact with the silicon tetrafluoride gas under the condition of ≧ k.
Here, V is the volume [liter] of the container filled with silicon,
Q is the flow rate [N liter / minute] of the silicon tetrafluoride gas generating gas,
k is defined as k = 18 / (d-291) +0.04;
d represents a temperature [° C.], respectively.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2002177850A JP3986376B2 (en) | 2002-06-19 | 2002-06-19 | Method for producing silicon tetrafluoride |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2002177850A JP3986376B2 (en) | 2002-06-19 | 2002-06-19 | Method for producing silicon tetrafluoride |
Publications (2)
Publication Number | Publication Date |
---|---|
JP2004018332A true JP2004018332A (en) | 2004-01-22 |
JP3986376B2 JP3986376B2 (en) | 2007-10-03 |
Family
ID=31175733
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2002177850A Expired - Fee Related JP3986376B2 (en) | 2002-06-19 | 2002-06-19 | Method for producing silicon tetrafluoride |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP3986376B2 (en) |
-
2002
- 2002-06-19 JP JP2002177850A patent/JP3986376B2/en not_active Expired - Fee Related
Also Published As
Publication number | Publication date |
---|---|
JP3986376B2 (en) | 2007-10-03 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
RU2368568C2 (en) | Method of obtaining silicon | |
EP2033937B1 (en) | Method for producing trichlorosilane and method for producing polycrystalline silicon | |
JP5442780B2 (en) | Purification method by distillation of chlorosilane | |
TWI474976B (en) | Production of polycrystalline silicon in substantially closed-loop processes that involve disproportionation operations | |
JP5122700B1 (en) | Monosilane purification method | |
EP3061727B1 (en) | Method for manufacturing polycrystalline silicon | |
KR20110015527A (en) | Method and system for the production of pure silicon | |
JP5511667B2 (en) | Method for producing hydrogen gas from hydrogen halide, mixed gas containing hydrogen and silicon halide, method for producing silicon compound using the hydrogen gas, and plant for the method | |
JP2017141150A (en) | Purification method of fluorine compound gas | |
AU782332B2 (en) | Method and apparatus for the production of nitrogen trifluoride | |
WO2017138366A1 (en) | Method for purifying fluorine compound gas | |
US8404205B2 (en) | Apparatus and method for producing polycrystalline silicon having a reduced amount of boron compounds by forming phosphorus-boron compounds | |
US7906094B2 (en) | Method for producing a high purity trisilane product from the pyrolysis of disilane | |
JP3986376B2 (en) | Method for producing silicon tetrafluoride | |
KR102326287B1 (en) | Method for manufacturing polycrystalline silicon | |
JP2003160324A (en) | Production method for silicon tetrafluoride | |
KR102405910B1 (en) | Pentachlorodisilane production method and pentachlorodisilane produced by same | |
JP5566290B2 (en) | Method for producing hydrogen gas from hydrogen halide, mixed gas containing hydrogen and silicon halide, method for producing silicon compound using the hydrogen gas, and plant for the method | |
JP3986375B2 (en) | Method for purifying silicon tetrafluoride | |
JP4588396B2 (en) | Method for producing tetrafluorosilane | |
JP2015113250A (en) | Method for purifying tetrachlorosilane | |
JP4498152B2 (en) | Method for purifying trimethylsilane | |
KR101556825B1 (en) | Device for separating exhaust emission discharged from cvd reactor for preparation of polysilicon and method for separating exhaust emission using the same | |
KR101556824B1 (en) | Device for separating exhaust emission discharged from cvd reactor for preparation of polysilicon and method for separating exhaust emission using the same | |
JPS6163515A (en) | Production of monosilane |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20050111 |
|
RD01 | Notification of change of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7421 Effective date: 20060421 |
|
A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20070628 |
|
TRDD | Decision of grant or rejection written | ||
A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20070710 |
|
A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20070710 |
|
R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100720 Year of fee payment: 3 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100720 Year of fee payment: 3 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100720 Year of fee payment: 3 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110720 Year of fee payment: 4 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110720 Year of fee payment: 4 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120720 Year of fee payment: 5 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120720 Year of fee payment: 5 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120720 Year of fee payment: 5 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130720 Year of fee payment: 6 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130720 Year of fee payment: 6 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
LAPS | Cancellation because of no payment of annual fees |