[go: up one dir, main page]

JP2010073729A - Method for cleaning semiconductor heat-treating tool - Google Patents

Method for cleaning semiconductor heat-treating tool Download PDF

Info

Publication number
JP2010073729A
JP2010073729A JP2008236410A JP2008236410A JP2010073729A JP 2010073729 A JP2010073729 A JP 2010073729A JP 2008236410 A JP2008236410 A JP 2008236410A JP 2008236410 A JP2008236410 A JP 2008236410A JP 2010073729 A JP2010073729 A JP 2010073729A
Authority
JP
Japan
Prior art keywords
cleaning
heat treatment
treatment jig
hydrofluoric acid
water
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.)
Withdrawn
Application number
JP2008236410A
Other languages
Japanese (ja)
Other versions
JP2010073729A5 (en
Inventor
Koji Matsumoto
光二 松本
Hisashi Adachi
尚志 足立
B Shabani Mohammad
モハマッド.ビー.シャバニ
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sumco Corp
Original Assignee
Sumco Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Sumco Corp filed Critical Sumco Corp
Priority to JP2008236410A priority Critical patent/JP2010073729A/en
Publication of JP2010073729A publication Critical patent/JP2010073729A/en
Publication of JP2010073729A5 publication Critical patent/JP2010073729A5/ja
Withdrawn legal-status Critical Current

Links

Landscapes

  • Cleaning Or Drying Semiconductors (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for cleaning a semiconductor heat-treating tool, which excellently removes contaminants and prevents surface roughening etc., of the semiconductor heat-treating tool. <P>SOLUTION: The present invention relates to the method of cleaning the semiconductor heat-treating tool used to hold a silicon substrate when the silicon substrate is heat-treated, and made of silicon. The method uses, as a cleaning liquid, a mixed liquid of nitric acid, acetic acid, and water or a mixture of water and acetic acid, prepared such that the nitric acid is blended at a mass rate of 1 to 8%, the acetic acid is blended at a mass rate of 35 to 70%, and water or a mixture of water and acetic acid is blended at a mass rate of 30 to 60%, and includes a cleaning step of cleaning the semiconductor heat-treating tool by etching the semiconductor heat-treating tool made of silicon using the cleaning liquid. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は、半導体熱処理治具の洗浄方法に関する。   The present invention relates to a method for cleaning a semiconductor heat treatment jig.

従来、例えばLSIデバイス製造プロセスにおいては、半導体シリコン基板(シリコンウェーハ)には酸化や拡散、成膜などの各処理工程毎で、高温の熱処理が繰り返し施される。このような熱処理の際には、通常はこのシリコン基板を所望の状態に保持するため、サセプタやウエハボートなどの熱処理治具が用いられる。   Conventionally, in an LSI device manufacturing process, for example, a semiconductor silicon substrate (silicon wafer) is repeatedly subjected to high-temperature heat treatment in each processing step such as oxidation, diffusion, and film formation. During such heat treatment, a heat treatment jig such as a susceptor or a wafer boat is usually used to hold the silicon substrate in a desired state.

このような熱処理治具としては、これ自身が汚染の原因とならないよう、例えば高純度な炭化珪素質材料が用いられている(例えば、特許文献1、特許文献2参照)。
ところが、熱処理温度が1100℃以上の高温になると、例えばシリコンとの熱膨張係数の違いからシリコンウェーハにスリップ転位を生じるため、熱処理治具としても、高純度なシリコンからなるものが用いられる。
特開平8−78376号公報 特開平5−243169号公報
As such a heat treatment jig, for example, a high-purity silicon carbide material is used so as not to cause contamination itself (see, for example, Patent Document 1 and Patent Document 2).
However, when the heat treatment temperature is higher than 1100 ° C., for example, slip dislocation occurs in the silicon wafer due to the difference in thermal expansion coefficient from silicon, and therefore, a heat treatment jig made of high-purity silicon is used.
JP-A-8-78376 JP-A-5-243169

しかしながら、このようなシリコンからなる熱処理治具にあっては、例えば金属工具により研削などの加工させるために、金属汚染されてしまうことがある。そして、このように金属汚染された熱処理治具をシリコン基板の熱処理に用いた場合、特に高温で熱処理した際には汚染物質(汚染金属)が拡散しやすくなるため、汚染物質が熱処理しているシリコン基板側に移行し、これを汚染してしまうことがある。   However, such a heat treatment jig made of silicon may be contaminated with metal due to, for example, grinding with a metal tool. When such a metal-contaminated heat treatment jig is used for heat treatment of a silicon substrate, the contaminant (contaminated metal) is likely to diffuse particularly when heat-treated at a high temperature. It may shift to the silicon substrate side and contaminate it.

すると、この汚染されたシリコン基板上に作製された半導体装置は、その電気特性が著しく劣化してしまうことがある。そこで、シリコン基板の熱処理に用いる熱処理治具については、使用に先立って洗浄処理を行い、汚染物質を十分に除去しておく必要がある。   Then, the electrical characteristics of the semiconductor device manufactured on the contaminated silicon substrate may be remarkably deteriorated. Therefore, a heat treatment jig used for heat treatment of the silicon substrate needs to be cleaned prior to use to sufficiently remove contaminants.

本発明は前記事情に鑑みてなされたもので、その目的とするところは、汚染物質を良好に除去することができ、しかも半導体熱処理治具の表面荒れ等も防止した、半導体熱処理治具の洗浄方法を提供することにある。   The present invention has been made in view of the above circumstances, and an object of the present invention is to clean a semiconductor heat treatment jig that can satisfactorily remove contaminants and prevent surface roughness of the semiconductor heat treatment jig. It is to provide a method.

本発明の半導体熱処理治具の洗浄方法は、シリコン基板を熱処理する際にこれを保持するために用いられる、シリコンからなる半導体熱処理治具の洗浄方法であって、
洗浄液として、弗酸の配合比が質量比で1%以上8%以下、硝酸の配合比が質量比で35%以上70%以下、水の配合比が質量比で30%以上60%以下に調製された弗酸と硝酸と水との混合液を用い、この洗浄液によって前記のシリコンからなる半導体熱処理治具をエッチングすることで、該半導体熱処理治具を洗浄する洗浄工程を有することを特徴としている。
The method for cleaning a semiconductor heat treatment jig of the present invention is a method for cleaning a semiconductor heat treatment jig made of silicon, which is used to hold a silicon substrate when it is heat-treated,
The cleaning liquid is prepared so that the mixing ratio of hydrofluoric acid is 1% to 8% by mass, the mixing ratio of nitric acid is 35% to 70% by mass, and the mixing ratio of water is 30% to 60% by mass. A cleaning step of cleaning the semiconductor heat treatment jig by using the mixed liquid of hydrofluoric acid, nitric acid and water and etching the semiconductor heat treatment jig made of silicon with the cleaning liquid. .

この半導体熱処理治具の洗浄方法によれば、弗酸と硝酸と水との混合液を洗浄液として用いているので、硝酸によってシリコンからなる半導体熱処理治具の表面を酸化し、弗酸によって形成したシリコン酸化層を溶解・除去することを繰り返すことにより、半導体熱処理治具の表層部をエッチングすることができる。また、弗酸、硝酸、水を前記した適宜な配合比に規定したので、後述する実験結果に示すように、半導体熱処理治具の表面に荒れなどの異常を生じることなく、良好にエッチングすることができる。   According to this method for cleaning a semiconductor heat treatment jig, since a mixed liquid of hydrofluoric acid, nitric acid and water is used as the cleaning liquid, the surface of the semiconductor heat treatment jig made of silicon is oxidized with nitric acid and formed with hydrofluoric acid. By repeatedly dissolving and removing the silicon oxide layer, the surface layer portion of the semiconductor heat treatment jig can be etched. In addition, since hydrofluoric acid, nitric acid, and water are specified in the above-described appropriate blending ratio, as shown in the experimental results described later, the surface of the semiconductor heat treatment jig can be etched well without causing abnormalities such as roughness. Can do.

本発明の他の半導体熱処理治具の洗浄方法は、シリコン基板を熱処理する際にこれを保持するために用いられる、シリコンからなる半導体熱処理治具の洗浄方法であって、
洗浄液として、弗酸の配合比が質量比で1%以上8%以下、硝酸の配合比が質量比で35%以上70%以下、酢酸と水との混合物の配合比が質量比で30%以上60%以下に調製された弗酸と硝酸と酢酸と水との混合液を用い、この洗浄液によって前記のシリコンからなる半導体熱処理治具をエッチングすることで、該半導体熱処理治具を洗浄する洗浄工程を有することを特徴としている。
Another method for cleaning a semiconductor heat treatment jig of the present invention is a method for cleaning a semiconductor heat treatment jig made of silicon, which is used to hold a silicon substrate when it is heat-treated,
As the cleaning liquid, the mixing ratio of hydrofluoric acid is 1% to 8% by mass, the mixing ratio of nitric acid is 35% to 70% by mass, and the mixture ratio of acetic acid and water is 30% or more by mass. A cleaning process for cleaning the semiconductor heat treatment jig by using a mixed liquid of hydrofluoric acid, nitric acid, acetic acid and water prepared to 60% or less and etching the semiconductor heat treatment jig made of silicon with the cleaning liquid. It is characterized by having.

この半導体熱処理治具の洗浄方法によれば、弗酸と硝酸と酢酸と水との混合液を洗浄液として用いているので、硝酸によってシリコンからなる半導体熱処理治具の表面を酸化し、弗酸によって形成したシリコン酸化層を溶解・除去することを繰り返すことにより、半導体熱処理治具の表層部をエッチングすることができる。また、弗酸、硝酸、酢酸と水との混合物を前記した適宜な配合比に規定したので、後述する実験結果に示すように、半導体熱処理治具の表面に荒れなどの異常を生じることなく、良好にエッチングすることができる。また、酢酸を加えることにより弗酸、硝酸と混ざりやすくなり、ムラなくエッチングすることができる。   According to this method for cleaning a semiconductor heat treatment jig, since a mixed liquid of hydrofluoric acid, nitric acid, acetic acid and water is used as the cleaning liquid, the surface of the semiconductor heat treatment jig made of silicon is oxidized by nitric acid, and the hydrofluoric acid is used. By repeatedly dissolving and removing the formed silicon oxide layer, the surface layer portion of the semiconductor heat treatment jig can be etched. In addition, since the mixture of hydrofluoric acid, nitric acid, acetic acid and water is defined as the appropriate blending ratio described above, as shown in the experimental results described later, without causing abnormalities such as roughening on the surface of the semiconductor heat treatment jig, It can etch well. Further, by adding acetic acid, it becomes easy to mix with hydrofluoric acid and nitric acid, and etching can be performed without unevenness.

また、前記半導体熱処理治具の洗浄方法においては、前記洗浄工程の後、該半導体熱処理治具を、弗酸水溶液に浸漬する弗酸処理工程と、その後、該半導体熱処理治具を水でリンスするリンス工程とを有するのが好ましい。その場合に、前記弗酸水溶液の弗酸の濃度が、質量比で0.5%以上20%以下であるのが好ましい。
このようにすれば、洗浄工程で半導体熱処理治具の表面に酸化膜が形成されても、弗酸処理工程においてこの半導体熱処理治具を弗酸水溶液に浸漬することにより、酸化膜を除去することができるうえエッチング処理後の硝酸による酸化を抑えることができ、汚染の焼きつきやエッチングムラを無くすことができる。また、その後リンス工程において水でリンスすることにより、半導体熱処理治具の表面に残った弗酸成分等を除去することができる。
In the method for cleaning a semiconductor heat treatment jig, after the cleaning step, the semiconductor heat treatment jig is immersed in a hydrofluoric acid aqueous solution, and then the semiconductor heat treatment jig is rinsed with water. A rinsing step. In that case, the concentration of hydrofluoric acid in the hydrofluoric acid aqueous solution is preferably 0.5% or more and 20% or less by mass ratio.
In this way, even if an oxide film is formed on the surface of the semiconductor heat treatment jig in the cleaning process, the oxide film can be removed by immersing the semiconductor heat treatment jig in the hydrofluoric acid aqueous solution in the hydrofluoric acid treatment process. In addition, oxidation by nitric acid after the etching process can be suppressed, and contamination burn-in and uneven etching can be eliminated. Further, the hydrofluoric acid component remaining on the surface of the semiconductor heat treatment jig can be removed by rinsing with water in the rinsing step.

また、前記半導体熱処理治具の洗浄方法においては、前記洗浄工程の前に、前記洗浄液を用いてダミーのシリコンを洗浄する、ダミー洗浄工程を有するのが好ましい。
このようにすれば、洗浄液中にダミーのシリコンを溶出させることで該洗浄液の初期のエッチング能を抑えることができる。したがって、半導体熱処理治具を該洗浄液に接触させた際、初期において急激なエッチングが起こり、これによってエッチングムラが生じるのを防止し、エッチング量を適正にすることができる。
The method for cleaning a semiconductor heat treatment jig preferably includes a dummy cleaning step of cleaning dummy silicon using the cleaning liquid before the cleaning step.
In this way, the initial etching ability of the cleaning liquid can be suppressed by eluting the dummy silicon into the cleaning liquid. Therefore, when the semiconductor heat treatment jig is brought into contact with the cleaning solution, rapid etching occurs in the initial stage, thereby preventing etching unevenness and making the etching amount appropriate.

本発明の半導体熱処理治具の洗浄方法にあっては、硝酸と弗酸との作用によって半導体熱処理治具の表層部をエッチングすることができ、これにより、例えば半導体熱処理治具の表層部に残存する汚染金属などの汚染物質を良好に除去することができる。また、弗酸、硝酸、水を適宜な配合比に規定し、あるいは、弗酸、硝酸、酢酸と水との混合物を適宜な配合比に規定したので、半導体熱処理治具の表面に荒れなどの異常を生じさせることなく、良好にエッチングすることができる。したがって、半導体熱処理治具の強度や精度を損なうことなく、これを良好に洗浄することができるため、半導体熱処理治具の破損やスリップ転位の起点となる凹凸ができることを防止して繰り返しによる長期使用を可能にし、コストの低減化を図ることができ、ウェーハの歩留まりを上げることができる。   In the method for cleaning a semiconductor heat treatment jig according to the present invention, the surface layer portion of the semiconductor heat treatment jig can be etched by the action of nitric acid and hydrofluoric acid. It is possible to satisfactorily remove contaminants such as contaminating metals. In addition, hydrofluoric acid, nitric acid, and water are regulated to an appropriate blending ratio, or a mixture of hydrofluoric acid, nitric acid, acetic acid, and water is regulated to an appropriate blending ratio. Etching can be satisfactorily performed without causing abnormality. Therefore, it can be cleaned well without losing the strength and accuracy of the semiconductor heat treatment jig, preventing the semiconductor heat treatment jig from being damaged and the formation of irregularities as the starting point of slip dislocation, and using it for a long period of time. Can be achieved, the cost can be reduced, and the yield of the wafer can be increased.

以下、本発明の半導体熱処理治具の洗浄方法を詳しく説明する。
本発明の洗浄方法の対象となる半導体熱処理治具(以下、熱処理治具と記す)としては、例えばLSIデバイス製造プロセスに供される半導体シリコン基板(シリコンウェーハ。以下、シリコン基板と記す。)を熱処理する際に、これを保持するのに用いられるシリコン製のもので、形態としては、サセプタやウエハボート、プロセスチューブ、容器など、シリコン基板に直接接触してこれを保持するものであれば、特に限定されることなく種々のものが適用可能である。
Hereinafter, the method for cleaning a semiconductor heat treatment jig of the present invention will be described in detail.
As a semiconductor heat treatment jig (hereinafter referred to as a heat treatment jig) to be subjected to the cleaning method of the present invention, for example, a semiconductor silicon substrate (silicon wafer; hereinafter referred to as a silicon substrate) used in an LSI device manufacturing process. It is made of silicon used to hold this during heat treatment, and the form is a susceptor, wafer boat, process tube, container, etc., as long as it is in direct contact with the silicon substrate and holds it, Various things are applicable without being specifically limited.

シリコン治具によるシリコン基板の熱処理については、特に高温熱処理の際に用いられ、具体的には、1100℃以上の高温で熱処理される際に好適に用いられる。しかし、シリコン治具は研削などの加工により金属汚染されていることがしばしばある。このような金属汚染されたシリコン治具を前出のような高温で用いると、例えば半導体シリコン基板中に金属が熱拡散し、その上に作製された半導体装置の特性を劣化させてしまう。   The heat treatment of the silicon substrate with the silicon jig is used particularly at the time of high temperature heat treatment, and specifically, it is suitably used when heat treatment is performed at a high temperature of 1100 ° C. or higher. However, the silicon jig is often contaminated with metal by processing such as grinding. When such a metal-contaminated silicon jig is used at a high temperature as described above, for example, the metal is thermally diffused into the semiconductor silicon substrate, and the characteristics of the semiconductor device fabricated thereon are deteriorated.

そこで、シリコン基板の熱処理に用いられる熱処理治具については、使用に先立って洗浄処理を行う。
すなわち、本発明はこのような洗浄処理に適用されるもので、シリコン製の熱処理治具中の汚染物質を除去するための方法である。本発明においては、第1の実施形態として、弗酸と硝酸と水との混合液からなる洗浄液(以下、第1の洗浄液と記す)を用いて熱処理治具の洗浄を行う。また、第2の実施形態として、弗酸と硝酸と酢酸と水との混合液からなる洗浄液(以下、第2の洗浄液と記す)を用いて熱処理治具の洗浄を行う。
Accordingly, a heat treatment jig used for heat treatment of the silicon substrate is subjected to a cleaning process before use.
That is, the present invention is applied to such a cleaning process, and is a method for removing contaminants in a silicon heat treatment jig. In the present invention, as a first embodiment, the heat treatment jig is cleaned using a cleaning liquid (hereinafter, referred to as a first cleaning liquid) made of a mixed liquid of hydrofluoric acid, nitric acid, and water. In the second embodiment, the heat treatment jig is cleaned using a cleaning liquid (hereinafter referred to as a second cleaning liquid) made of a mixed liquid of hydrofluoric acid, nitric acid, acetic acid, and water.

第1の洗浄液は、前記したように弗酸と硝酸と水との混合液からなるもので、特に弗酸の配合比が質量比で1%以上8%以下、硝酸の配合比が質量比で35%以上70%以下、水の配合比が質量比で30%以上60%以下に調製されたものである。また、第2の洗浄液は、前記したように弗酸と硝酸と酢酸と水との混合液からなるもので、特に弗酸の配合比が質量比で1%以上8%以下、硝酸の配合比が質量比で35%以上70%以下、酢酸と水との混合物の配合比が質量比で30%以上60%以下に調製されたものである。   The first cleaning liquid is composed of a mixed liquid of hydrofluoric acid, nitric acid and water as described above. In particular, the mixing ratio of hydrofluoric acid is 1% to 8% by mass, and the mixing ratio of nitric acid is by mass. 35% to 70%, and the mixing ratio of water is 30% to 60% by mass. The second cleaning liquid is composed of a mixed liquid of hydrofluoric acid, nitric acid, acetic acid and water as described above. In particular, the mixing ratio of hydrofluoric acid is 1% to 8% by mass, and the mixing ratio of nitric acid. Is prepared in a mass ratio of 35% to 70% and a mixture ratio of a mixture of acetic acid and water is 30% to 60% by mass ratio.

このような第1の洗浄液、第2の洗浄液にあっては、硝酸によってシリコンからなる熱処理治具の表面を酸化し、弗酸によって形成したシリコン酸化層を溶解することにより、このシリコン酸化膜を熱処理治具から除去することができる。したがって、このような酸化と溶解・除去とを繰り返すことにより、半導体熱処理治具の表層部をエッチングすることができる。すなわち、表層部に拡散された汚染金属等の汚染物質を、エッチングによって良好に除去することができる。   In the first cleaning liquid and the second cleaning liquid, the surface of the heat treatment jig made of silicon is oxidized with nitric acid, and the silicon oxide layer formed with hydrofluoric acid is dissolved. It can be removed from the heat treatment jig. Therefore, the surface layer portion of the semiconductor heat treatment jig can be etched by repeating such oxidation and dissolution / removal. That is, contaminants such as contaminated metals diffused in the surface layer can be satisfactorily removed by etching.

ただし、このような酸化と溶解・除去とは、それぞれの反応速度が速くなり、エッチング速度が速くなると、熱処理治具の表面が荒れてしまったりエッチング速度が制御できないためにエッチングムラを引き起こす。すなわち、表面荒れが起こると、高温での熱処理の際に凹凸によりそこを起点としてスリップ転位が導入されやすくなる。また、エッチングムラは治具の寸法精度を狂わせ、ウェーハの機械搬送などに支障をきたす。   However, such oxidation and dissolution / removal increase the respective reaction rates, and when the etching rate is increased, the surface of the heat treatment jig is roughened, and the etching rate cannot be controlled, thereby causing uneven etching. That is, when surface roughness occurs, slip dislocations are likely to be introduced starting from the unevenness during heat treatment at a high temperature. In addition, the etching unevenness deviates the dimensional accuracy of the jig, and hinders the mechanical transfer of the wafer.

そこで、本発明では、硝酸による酸化能、弗酸による溶解・除去能を制御し、これによって両者の作用に基づくエッチング能を制御することにより、エッチング速度を適正に制御するようにしている。すなわち、第1の洗浄液ではこれら硝酸、弗酸に水を加えて混合し、かつ、それぞれの配合比を所定比に調製することで、この第1の洗浄液によるエッチング速度を適正に制御している。また、第2の洗浄液ではこれら硝酸、弗酸に酢酸と水との混合液を加えて混合し、かつ、それぞれの配合比を所定比に調製することで、この第1の洗浄液によるエッチング速度を適正に制御している。   Therefore, in the present invention, the etching rate is appropriately controlled by controlling the oxidizing ability by nitric acid and the dissolving / removing ability by hydrofluoric acid, thereby controlling the etching ability based on the action of both. That is, in the first cleaning liquid, water is added to and mixed with these nitric acid and hydrofluoric acid, and the respective mixing ratios are adjusted to predetermined ratios, so that the etching rate by the first cleaning liquid is appropriately controlled. . Further, in the second cleaning liquid, a mixed liquid of acetic acid and water is added to nitric acid and hydrofluoric acid and mixed, and the respective mixing ratios are adjusted to a predetermined ratio, so that the etching rate by the first cleaning liquid can be increased. Appropriate control.

エッチング速度を適正にするには、第1の洗浄液、あるいは第2の洗浄液において弗酸の配合比(混合比)を、質量比で全体の1%以上8%以下に調製する。1%未満にすると、エッチング速度が遅くなり過ぎてエッチングが進みにくくなり、洗浄工程に要する時間が長くなって生産性が損なわれるからである。また、8%を超えると、エッチング速度が速くなり過ぎて前述したように熱処理治具に表面荒れが起き易くなってしまうからである。したがって、弗酸の配合比(混合比)を1%以上8%以下に調製する必要があり、特に4%程度にするのが好ましい。   In order to make the etching rate appropriate, the blending ratio (mixing ratio) of hydrofluoric acid in the first cleaning liquid or the second cleaning liquid is adjusted to 1% or more and 8% or less of the entire mass ratio. If it is less than 1%, the etching rate becomes too slow and etching becomes difficult to proceed, and the time required for the cleaning process becomes longer and the productivity is impaired. On the other hand, if it exceeds 8%, the etching rate becomes too fast, and the surface roughness of the heat treatment jig tends to occur as described above. Therefore, it is necessary to adjust the blending ratio (mixing ratio) of hydrofluoric acid to 1% or more and 8% or less, and it is particularly preferable to set it to about 4%.

また、硝酸の配合比(混合比)については、質量比で全体の35%以上70%以下に調製する。35%未満であると、酸化反応が抑えられる分エッチング速度も進みにくくなり、洗浄工程に要する時間が長くなって生産性が損なわれるからである。また、70%を超えると、酸化反応が速くなる分エッチング速度も速くなり、前述したように熱処理治具に表面荒れが起き易くなってしまうからである。したがって、硝酸の配合比(混合比)を1%以上8%以下に調製する必要があり、特に45%程度にするのが好ましい。   Moreover, about the compounding ratio (mixing ratio) of nitric acid, it prepares by 35 to 70% of the whole by mass ratio. If it is less than 35%, the etching rate is difficult to proceed as much as the oxidation reaction is suppressed, and the time required for the cleaning process becomes longer and the productivity is impaired. On the other hand, if it exceeds 70%, the etching rate increases as the oxidation reaction increases, and the surface roughness of the heat treatment jig tends to occur as described above. Therefore, it is necessary to adjust the mixing ratio (mixing ratio) of nitric acid to 1% or more and 8% or less, and it is particularly preferably about 45%.

なお、これら弗酸や硝酸は、洗浄液の調製に際しては、弗酸水溶液、硝酸水溶液として、用いられ、混合される。すなわち、一般に市販される試薬などの形態で用いられ、混合されて洗浄液に調製される。
そして、これら弗酸水溶液中、および硝酸水溶液中の水は、第1の洗浄液を構成する水、あるいは第2の洗浄液を構成する水となる。
These hydrofluoric acid and nitric acid are used and mixed as a hydrofluoric acid aqueous solution and a nitric acid aqueous solution when preparing the cleaning liquid. That is, it is generally used in the form of a commercially available reagent, etc., and mixed to prepare a cleaning liquid.
The water in the hydrofluoric acid aqueous solution and the nitric acid aqueous solution becomes water constituting the first cleaning liquid or water constituting the second cleaning liquid.

第1の洗浄液においては、弗酸、硝酸の他に水が配合される。水は、前記したように弗酸や硝酸を溶解することでこれらを水溶液とし、これによって洗浄液の作製(調製)を容易にするとともに、弗酸、硝酸を薄めることで、これらの溶解・除去能や酸化能を抑え、エッチング速度を適正範囲に抑えるためのものである。このような水の、第1の洗浄液における配合比(混合比)については、質量比で全体の30%以上60%以下に調製される。30%未満であると、エッチング速度が速くなってしまい、熱処理治具に表面荒れが起きやすくなってしまうからである。また、60%を超えると、弗酸、硝酸によるエッチング能が低下することで、洗浄処理後の熱処理治具に部分的に集中した状態で汚染物質が残留してしまうおそれがあるからである。したがって、水の配合比(混合比)を30%以上60%以下に調製する必要があり、特に50%程度にするのが好ましい。   In the first cleaning liquid, water is blended in addition to hydrofluoric acid and nitric acid. As described above, water dissolves hydrofluoric acid and nitric acid to make them aqueous solutions, thereby facilitating the preparation (preparation) of the cleaning liquid, and diluting hydrofluoric acid and nitric acid to dissolve and remove them. In order to suppress the oxidation ability and the etching rate within an appropriate range. The blending ratio (mixing ratio) of such water in the first cleaning liquid is adjusted to 30% or more and 60% or less of the whole by mass ratio. This is because if it is less than 30%, the etching rate is increased, and the surface roughness of the heat treatment jig tends to occur. On the other hand, if it exceeds 60%, the etching ability by hydrofluoric acid and nitric acid is lowered, and there is a possibility that contaminants may remain in a state of being partially concentrated on the heat treatment jig after the cleaning treatment. Therefore, it is necessary to adjust the mixing ratio (mixing ratio) of water to 30% or more and 60% or less, and it is particularly preferable to set the mixing ratio to about 50%.

一方、第2の洗浄液においては、弗酸、硝酸の他に、酢酸と水との混合物が配合される。すなわち、この第2の洗浄液では、弗酸水溶液と硝酸水溶液に対して酢酸水溶液が加えられ、さらに必要に応じて水が加えられることにより、弗酸、硝酸、酢酸、水の4成分系の洗浄液が形成される。酢酸と水は、第1の洗浄液における水と同様に、弗酸、硝酸を薄めることで、これらの溶解・除去能や酸化能を抑え、エッチング速度を適正範囲に抑えるためのものである。このような酢酸と水との混合物の、第2の洗浄液における配合比(混合比)については、質量比で全体の30%以上60%以下に調製される。30%未満であると、エッチング速度が速くなってしまい、熱処理治具に表面荒れが起きやすくなってしまうからである。また、60%を超えると、弗酸、硝酸によるエッチング能が低下することで、洗浄処理後の熱処理治具に部分的に集中した状態で汚染物質が残留してしまうおそれがあるからである。したがって、酢酸と水との混合物の配合比(混合比)を30%以上60%以下に調製する必要があり、特に50%程度にするのが好ましい。   On the other hand, in the second cleaning liquid, a mixture of acetic acid and water is blended in addition to hydrofluoric acid and nitric acid. That is, in this second cleaning liquid, an aqueous acetic acid solution is added to an aqueous hydrofluoric acid solution and an aqueous nitric acid solution, and water is added as necessary, so that a four-component cleaning solution of hydrofluoric acid, nitric acid, acetic acid and water is added. Is formed. Acetic acid and water are used to reduce the dissolution / removal ability and oxidation ability and to keep the etching rate within an appropriate range by diluting hydrofluoric acid and nitric acid, similarly to the water in the first cleaning liquid. The blending ratio (mixing ratio) of such a mixture of acetic acid and water in the second cleaning liquid is adjusted to 30% or more and 60% or less of the entire mass ratio. This is because if it is less than 30%, the etching rate is increased, and the surface roughness of the heat treatment jig tends to occur. On the other hand, if it exceeds 60%, the etching ability by hydrofluoric acid and nitric acid is lowered, and there is a possibility that contaminants may remain in a state of being partially concentrated on the heat treatment jig after the cleaning treatment. Therefore, it is necessary to adjust the blending ratio (mixing ratio) of the mixture of acetic acid and water to 30% or more and 60% or less, and particularly preferably about 50%.

なお、第1の洗浄液については、前記の弗酸、硝酸、水の3成分以外にも、エッチング能に影響を与えない範囲で水と同等の機能を有するものや、意図しない不純物などが入っていてもよい。同様に、第2の洗浄液についても、前記の弗酸、硝酸、酢酸、水の4成分以外に、エッチング能に影響を与えない範囲で酢酸や水と同等の機能を有するものや、意図しない不純物などが入っていてもよい。また、水については、当然ながら純水を用いるのが好ましい。   In addition to the above three components of hydrofluoric acid, nitric acid, and water, the first cleaning liquid contains a liquid having a function equivalent to that of water as long as it does not affect the etching performance, and an unintended impurity. May be. Similarly, with respect to the second cleaning liquid, in addition to the above four components of hydrofluoric acid, nitric acid, acetic acid, and water, those having functions equivalent to acetic acid and water as long as they do not affect the etching performance, and unintended impurities Etc. may be included. Of course, it is preferable to use pure water.

本発明の洗浄方法では、このような第1あるいは第2の洗浄液を用い、シリコンからなる熱処理治具をエッチングすることで、これを洗浄する(洗浄工程)。具体的には、洗浄液を入れた処理槽中に熱処理治具を浸漬し、所定時間経過後、引き上げる。すると、前述したように硝酸の酸化能、弗酸による溶解・除去能により、熱処理治具の表層部が良好にエッチングされる。また、弗酸、硝酸、水、あるいは弗酸、硝酸、酢酸、水を適宜な配合比に規定し調製しているで、熱処理治具の表面に荒れなどの異常を生じることなく、良好にエッチングされる。   In the cleaning method of the present invention, such a first or second cleaning solution is used to etch a heat treatment jig made of silicon, thereby cleaning it (cleaning step). Specifically, the heat treatment jig is immersed in a treatment tank containing a cleaning solution and pulled up after a predetermined time has elapsed. Then, as described above, the surface layer portion of the heat treatment jig is satisfactorily etched by the ability to oxidize nitric acid and the ability to dissolve and remove with hydrofluoric acid. In addition, hydrofluoric acid, nitric acid, water, or hydrofluoric acid, nitric acid, acetic acid, and water are prepared with an appropriate blending ratio, so that etching can be performed satisfactorily without causing abnormalities such as roughening on the surface of the heat treatment jig. Is done.

なお、処理槽中の前記洗浄液については、撹拌機などを用いて十分に混合しておくのが好ましく、処理中においても、撹拌・混合を行うのが好ましい。
また、洗浄液の温度については、常温(例えば20℃)から70℃程度の範囲に調製しておくのが好ましい。常温より低温にすれば、エッチング速度を抑えることはできるものの、冷却が必要となり、コストアップを招いてしまうからである。また、70℃を超えると、酸化や溶解・除去の反応が活性化され、エッチングムラを生じるおそれがあるからである。
In addition, about the said washing | cleaning liquid in a processing tank, it is preferable to fully mix using a stirrer etc., and it is preferable to perform stirring and mixing also during a process.
In addition, the temperature of the cleaning liquid is preferably adjusted in a range from room temperature (for example, 20 ° C.) to about 70 ° C. This is because if the temperature is lower than room temperature, the etching rate can be suppressed, but cooling is required, resulting in an increase in cost. Moreover, when it exceeds 70 degreeC, reaction of oxidation, melt | dissolution / removal is activated, and there exists a possibility of producing an etching nonuniformity.

また、洗浄時間(浸漬時間)については、熱処理治具の汚染の度合いや、洗浄液の弗酸や硝酸の濃度(混合比)によっても異なるものの、5分〜20分程度、好ましくは10分程度とされる。このような時間で行えば、比較的時間管理が容易であり、かつ、生産性も良好になるからである。なお、洗浄液の各薬液(弗酸、硝酸)の濃度(配合比)からシリコンに対するエッチング速度を実験やシミュレーション等によって予め求めておき、熱処理治具の汚染の度合から、この熱処理治具をどの程度の深さまでエッチングするかを決定し、このエッチング深さに基づいて洗浄時間を決定するのが好ましい。   The cleaning time (immersion time) varies depending on the degree of contamination of the heat treatment jig and the concentration (mixing ratio) of hydrofluoric acid and nitric acid in the cleaning liquid, but is about 5 to 20 minutes, preferably about 10 minutes. Is done. This is because the time management is relatively easy and the productivity is improved by performing in such a time. It should be noted that the etching rate for silicon is determined in advance by experiments and simulations from the concentration (mixing ratio) of each chemical solution (hydrofluoric acid, nitric acid) in the cleaning liquid, and how much this heat treatment jig is used from the degree of contamination of the heat treatment jig. It is preferable to determine whether the etching is performed up to this depth, and to determine the cleaning time based on this etching depth.

ただし、本発明では、このような洗浄工程に先立ち、この洗浄工程に用いる洗浄液を用いて、ダミー洗浄処理を行うのが好ましい。このダミー洗浄処理を行うダミー洗浄工程は、具体的には、熱処理治具のダミーとなるシリコン、例えばシリコン基板やこれを適宜な形状・大きさに切断したシリコンブロックを、前記洗浄液中に所定時間浸漬し、その後引き上げることで行う。なお、このダミーのシリコンについては、汚染のおそれがない純度の高いものを用いる。   However, in the present invention, prior to such a cleaning process, it is preferable to perform a dummy cleaning process using a cleaning liquid used in this cleaning process. Specifically, the dummy cleaning process for performing the dummy cleaning process is performed by using a silicon serving as a dummy for the heat treatment jig, for example, a silicon substrate or a silicon block obtained by cutting the silicon substrate in an appropriate shape and size in the cleaning liquid for a predetermined time. Immerse and then pull it up. As the dummy silicon, high-purity silicon that does not cause contamination is used.

このようなダミー洗浄処理を行うと、洗浄処理に用いていない純粋な洗浄液中にシリコンを溶出させることで、該洗浄液の初期のエッチング能を抑えることができる。したがって、前記の洗浄工程において熱処理治具を該洗浄液に接触させた際、初期において急激なエッチングが起こり、これによってエッチングムラが生じるのを防止し、エッチング量を適正にすることができる。   When such a dummy cleaning process is performed, the initial etching ability of the cleaning liquid can be suppressed by eluting silicon into a pure cleaning liquid not used in the cleaning process. Therefore, when the heat treatment jig is brought into contact with the cleaning solution in the cleaning step, it is possible to prevent rapid etching in the initial stage, thereby causing uneven etching, and make the etching amount appropriate.

このダミー洗浄処理における、ダミーのシリコンの浸漬時間としては、洗浄液の量やダミーの大きさによっても異なるものの、5分〜30分程度、好ましくは15分程度とされる。このような時間で行えば、比較的時間管理が容易であり、かつ、生産性も良好になるからである。   In this dummy cleaning process, the immersion time of the dummy silicon is about 5 to 30 minutes, preferably about 15 minutes, although it varies depending on the amount of the cleaning liquid and the size of the dummy. This is because the time management is relatively easy and the productivity is improved by performing in such a time.

また、本発明では、前記の洗浄工程の後、処理後の熱処理治具を、弗酸処理工程において弗酸水溶液に浸漬するのが好ましい。このように弗酸水溶液に浸漬することにより、前記の洗浄工程で熱処理治具の表面に酸化膜が形成され、それが残っていても、弗酸水溶液で酸化膜を除去し、純粋なシリコン面を露出させることができるうえ、汚染の焼きつきやエッチングムラを無くすことができる。   In the present invention, it is preferable that the heat treatment jig after the treatment is immersed in a hydrofluoric acid aqueous solution in the hydrofluoric acid treatment step after the cleaning step. By immersing in the hydrofluoric acid aqueous solution in this manner, an oxide film is formed on the surface of the heat treatment jig in the cleaning step, and even if it remains, the oxide film is removed with the hydrofluoric acid aqueous solution to obtain a pure silicon surface. Can be exposed and contamination burn-in and etching unevenness can be eliminated.

ここで、この弗酸処理工程に用いる弗酸水溶液としては、弗酸の濃度が、質量比で0.5%以上20%以下のものを用いるのが好ましい。0.5%未満では、酸化膜の溶解・除去能が低く、処理に比較的長い時間を要することで、生産性が低下する。また、20%を超えると、溶解・除去能が高くなり過ぎ、エッチングムラを生じるおそれがあるからである。   Here, as the hydrofluoric acid aqueous solution used in this hydrofluoric acid treatment step, it is preferable to use a hydrofluoric acid concentration having a mass ratio of 0.5% to 20%. If it is less than 0.5%, the ability to dissolve and remove the oxide film is low, and the processing requires a relatively long time, so that the productivity is lowered. On the other hand, if it exceeds 20%, the dissolution / removal ability becomes too high, and etching unevenness may occur.

そして、このような弗酸処理工程を終了したら、続いて、処理後の熱処理治具をリンス工程において水でリンスするのが好ましい。このリンス工程においては、水として、当然ながら半導体プロセスで一般的に用いられる純水を用いる。処理の形態としては、例えば純水を入れた処理槽中に浸漬し、さらに処理槽中の純水をオーバーフローさせることで行う。また、純水をシャワー状に噴出させ、これで熱処理治具をリンス処理するようにしてもよい。処理時間については、熱処理治具に弗酸や弗酸処理工程で生じた塩などが残留しないよう、これらを確実に除去できるように十分な長さ(例えば1時間程度)で行う。   When such a hydrofluoric acid treatment step is completed, it is preferable to subsequently rinse the heat treatment jig after the treatment with water in the rinse step. In this rinsing step, as a matter of course, pure water generally used in a semiconductor process is used as water. As a form of the treatment, for example, the treatment is performed by immersing in a treatment tank containing pure water and overflowing the pure water in the treatment tank. Further, pure water may be ejected in the form of a shower so that the heat treatment jig is rinsed. The treatment time is set to a sufficient length (for example, about 1 hour) so that hydrofluoric acid and salts generated in the hydrofluoric acid treatment process do not remain in the heat treatment jig so that they can be removed reliably.

このように水(純水)でリンスすることにより、熱処理治具の表面に残った弗酸成分等を除去することができる。
なお、本発明の洗浄方法においては、洗浄工程後、熱処理治具にほとんど酸化膜が残らない場合には、前記の弗酸処理工程を省略することができる。ただし、その場合にも、洗浄工程によって熱処理治具表面に洗浄液が残留するため、この洗浄工程後にリンス工程を行うのが好ましい。
また、洗浄工程で使用する洗浄液については、前記のダミー洗浄処理を行う以外は、汚染物質が入り込むのを防止するため、別の処理に供することなく、調製後の純粋な状態で用いるのが望ましい。
By rinsing with water (pure water) in this way, the hydrofluoric acid component remaining on the surface of the heat treatment jig can be removed.
In the cleaning method of the present invention, the hydrofluoric acid treatment step can be omitted if almost no oxide film remains on the heat treatment jig after the cleaning step. However, even in that case, since the cleaning liquid remains on the surface of the heat treatment jig by the cleaning process, it is preferable to perform a rinsing process after the cleaning process.
In addition, the cleaning liquid used in the cleaning step is preferably used in a pure state after preparation without being subjected to another process in order to prevent contamination from entering, except for performing the dummy cleaning process described above. .

このように本発明の熱処理治具の洗浄方法にあっては、硝酸と弗酸との作用によって半導体熱処理治具の表層部をエッチングすることができ、これにより、例えば熱処理治具の表層部に拡散した汚染金属などの汚染物質を良好に除去することができる。したがって、このような洗浄を行った熱処理治具によれば、これを用いてシリコン基板を熱処理した際、汚染物質を拡散してシリコン基板を汚染してしまうおそれがなく、よって、汚染物質に起因する特性低下を防止することができる。   As described above, in the method for cleaning a heat treatment jig of the present invention, the surface layer portion of the semiconductor heat treatment jig can be etched by the action of nitric acid and hydrofluoric acid. Contaminants such as diffused contaminant metals can be removed well. Therefore, according to the heat treatment jig subjected to such cleaning, when the silicon substrate is heat-treated using the jig, there is no risk of diffusing the contaminants and contaminating the silicon substrate. It is possible to prevent the deterioration of characteristics.

また、弗酸、硝酸、水を適宜な配合比に規定し、あるいは、弗酸、硝酸、酢酸と水との混合物を適宜な配合比に規定したので、熱処理治具の表面に荒れなどの異常を生じさせることなく、良好にエッチングすることができる。したがって、熱処理治具の強度を損なうことなく、これを良好に洗浄することができるため、熱処理治具の破損やスリップ転位の起点となる凹凸ができることを防止して繰り返しによる長期使用を可能にし、コストの低減化を図ることができ、ウェーハの歩留まりを上げることができる。   In addition, hydrofluoric acid, nitric acid, and water are specified in an appropriate mixing ratio, or a mixture of hydrofluoric acid, nitric acid, acetic acid, and water is specified in an appropriate mixing ratio. Etching can be carried out satisfactorily without causing. Therefore, since it can be cleaned well without losing the strength of the heat treatment jig, it is possible to prevent the heat treatment jig from being damaged and to form irregularities that become the starting point of slip dislocation, and to be used for a long time by repetition. Costs can be reduced and the yield of wafers can be increased.

[実験例]
次に、熱処理に供した後のシリコン製の熱処理治具を、本発明に係る洗浄液を用いて以下のように洗浄処理した。
[Experimental example]
Next, the heat treatment jig made of silicon after being subjected to the heat treatment was cleaned as follows using the cleaning liquid according to the present invention.

(実施例1)
純水30L(リットル)と、質量比で50%の弗酸7Lと、質量比で70%の硝酸70Lと、を処理槽内にて混合した。各薬液の濃度から、この混合液の各成分比(配合比)は、質量比で弗酸が3%、硝酸が46%、水が51%となり、本発明における前記第1の洗浄液となった。
このようにして調製した洗浄液を前記処理槽内にてよく撹拌し混合した後、この洗浄液中にダミーのシリコンを浸漬した。そして、その状態で15分間放置した後、このダミーのシリコンを洗浄液中から取り出した(ダミー洗浄工程)。
Example 1
30 L (liters) of pure water, 7 L of hydrofluoric acid having a mass ratio of 50%, and 70 L of nitric acid having a mass ratio of 70% were mixed in a treatment tank. From the concentration of each chemical solution, each component ratio (compounding ratio) of this mixed solution was 3% hydrofluoric acid, 46% nitric acid, and 51% water in mass ratio, which was the first cleaning liquid in the present invention. .
The cleaning liquid thus prepared was thoroughly stirred and mixed in the treatment tank, and then dummy silicon was immersed in the cleaning liquid. Then, after leaving in that state for 15 minutes, the dummy silicon was taken out of the cleaning solution (dummy cleaning step).

続いて、前記の熱処理治具を前記洗浄液中に浸漬し、10分間放置して洗浄処理(エッチング処理)を行った(洗浄工程)。ここでは、エッチング深さを30μmに想定し、処理時間(エッチング時間)を決定した。なお、この洗浄処理中、洗浄液については攪拌機によって撹拌・混合を行った。また、洗浄液の温度については、常温(約20℃)で行った。   Subsequently, the heat treatment jig was immersed in the cleaning solution and left for 10 minutes to perform a cleaning process (etching process) (cleaning process). Here, the etching time was assumed to be 30 μm, and the processing time (etching time) was determined. During this cleaning process, the cleaning liquid was stirred and mixed with a stirrer. Moreover, about the temperature of the washing | cleaning liquid, it carried out at normal temperature (about 20 degreeC).

洗浄処理後、洗浄液からすばやく熱処理治具を引き上げ、別に用意した弗酸水溶液(質量比で弗酸の濃度が2.5%)中に10分間浸漬した(弗酸処理工程)。その後、弗酸水溶液中から熱処理治具を引き上げ、別に用意した処理槽中の純水中に浸漬し、1時間放置した。この処理槽では、純水をオーバーフローさせつつ、熱処理治具を純水でリンスした(リンス工程)。その後、純水中から熱処理治具を引き上げ、クリーン度の高い場所で自然乾燥させた。
このようにして洗浄・乾燥を行った熱処理治具について、その汚染の状態と外観とを調べた。
After the cleaning treatment, the heat treatment jig was quickly pulled up from the cleaning solution and immersed in a separately prepared hydrofluoric acid aqueous solution (the concentration of hydrofluoric acid was 2.5% by mass ratio) for 10 minutes (hydrofluoric acid treatment step). Thereafter, the heat treatment jig was pulled up from the hydrofluoric acid aqueous solution, immersed in pure water in a separately prepared treatment tank, and left for 1 hour. In this treatment tank, the heat treatment jig was rinsed with pure water while rinsing the pure water (rinsing step). Thereafter, the heat treatment jig was pulled up from the pure water and naturally dried in a clean place.
The heat treatment jig cleaned and dried in this manner was examined for its contamination state and appearance.

(実施例2)
酢酸30L(リットル)と、質量比で50%の弗酸4Lと、質量比で70%の硝酸40Lと、を処理槽内にて混合した。各薬液の濃度から、この混合液の各成分比(配合比)は、質量比で弗酸が3%、硝酸が38%、酢酸と水との混合物が60%となり、本発明における前記第2の洗浄液となった。
このようにして洗浄液を調製したら、以下、前記の実施例1と同様にしてダミー洗浄工程、洗浄工程、弗酸処理工程、リンス工程を順次行い、さらに乾燥した。
このようにして洗浄・乾燥を行った熱処理治具について、その汚染の状態と外観とを実施例1と同様にして調べた。
(Example 2)
30 L (liter) of acetic acid, 4 L of hydrofluoric acid having a mass ratio of 50%, and 40 L of nitric acid having a mass ratio of 70% were mixed in a treatment tank. From the concentration of each chemical solution, each component ratio (mixing ratio) of this mixed solution is 3% by weight in hydrofluoric acid, 38% in nitric acid, and 60% in a mixture of acetic acid and water. It became the washing liquid.
After preparing the cleaning solution in this manner, the dummy cleaning step, the cleaning step, the hydrofluoric acid treatment step, and the rinsing step were sequentially performed in the same manner as in Example 1 and further dried.
The heat treatment jig thus cleaned and dried was examined for contamination and appearance in the same manner as in Example 1.

(比較例1)
質量比で50%の弗酸16Lと、質量比で70%の硝酸64Lと、を処理槽内にて混合した。各薬液の濃度から、この混合液の各成分比(配合比)は、質量比で弗酸が10%、硝酸が56%、水が34%となり、弗酸の配合比(濃度)が、本発明における前記第1の洗浄液の基準を満たしていないものとなった。
このようにして洗浄液を調製したら、以下、前記の実施例1と同様にしてダミー洗浄工程、洗浄工程、弗酸処理工程、リンス工程を順次行い、さらに乾燥した。
このようにして洗浄・乾燥を行った熱処理治具について、その汚染の状態と外観とを実施例1と同様にして調べた。
(Comparative Example 1)
16 L of hydrofluoric acid having a mass ratio of 50% and 64 L of nitric acid having a mass ratio of 70% were mixed in a treatment tank. From the concentration of each chemical solution, the component ratio (mixing ratio) of this liquid mixture is 10% for hydrofluoric acid, 56% for nitric acid and 34% for water, and the mixing ratio (concentration) of hydrofluoric acid is as follows. The first cleaning liquid standard in the invention was not satisfied.
After preparing the cleaning solution in this manner, the dummy cleaning step, the cleaning step, the hydrofluoric acid treatment step, and the rinsing step were sequentially performed in the same manner as in Example 1 and further dried.
The heat treatment jig thus cleaned and dried was examined for contamination and appearance in the same manner as in Example 1.

(比較例2)
純水60Lと、質量比で50%の弗酸2Lと、質量比で70%の硝酸20Lと、を処理槽内にて混合した。各薬液の濃度から、この混合液の各成分比(配合比)は、質量比で弗酸が1%、硝酸が17%、水が82%となり、水と硝酸の配合比(濃度)が、本発明における前記第1の洗浄液の基準を満たしていないものとなった。
このようにして洗浄液を調製したら、以下、前記の実施例1と同様にしてダミー洗浄工程、洗浄工程、弗酸処理工程、リンス工程を順次行い、さらに乾燥した。
このようにして洗浄・乾燥を行った熱処理治具について、その汚染の状態と外観とを実施例1と同様にして調べた。
(Comparative Example 2)
60 L of pure water, 2 L of hydrofluoric acid having a mass ratio of 50%, and 20 L of nitric acid having a mass ratio of 70% were mixed in a treatment tank. From the concentration of each chemical solution, each component ratio (combination ratio) of this mixed solution is 1% hydrofluoric acid, 17% nitric acid, 82% water, and the mixing ratio (concentration) of water and nitric acid is: The criteria for the first cleaning liquid in the present invention were not satisfied.
After preparing the cleaning solution in this manner, the dummy cleaning step, the cleaning step, the hydrofluoric acid treatment step, and the rinsing step were sequentially performed in the same manner as in Example 1 and further dried.
The heat treatment jig thus cleaned and dried was examined for contamination and appearance in the same manner as in Example 1.

(比較例3)
純水40Lと、質量比で50%の弗酸4Lと、質量比で40%の硝酸20Lと、を処理槽内にて混合した。各薬液の濃度から、この混合液の各成分比(配合比)は、質量比で弗酸が2%、硝酸が34%、水が64%となり、水と硝酸の配合比(濃度)が、本発明における前記第1の洗浄液の基準を満たしていないものとなった。
このようにして洗浄液を調製したら、以下、前記の実施例1と同様にしてダミー洗浄工程、洗浄工程、弗酸処理工程、リンス工程を順次行い、さらに乾燥した。
このようにして洗浄・乾燥を行った熱処理治具について、その汚染の状態と外観とを実施例1と同様にして調べた。
(Comparative Example 3)
40 L of pure water, 4 L of hydrofluoric acid having a mass ratio of 50%, and 20 L of nitric acid having a mass ratio of 40% were mixed in a treatment tank. From the concentration of each chemical solution, each component ratio (combination ratio) of this mixed solution is 2% hydrofluoric acid, 34% nitric acid, 64% water, and the mixing ratio (concentration) of water and nitric acid is: The criteria for the first cleaning liquid in the present invention were not satisfied.
After preparing the cleaning solution in this manner, the dummy cleaning step, the cleaning step, the hydrofluoric acid treatment step, and the rinsing step were sequentially performed in the same manner as in Example 1 and further dried.
The heat treatment jig thus cleaned and dried was examined for contamination and appearance in the same manner as in Example 1.

(比較例4)
前記の熱処理後の熱処理治具を、洗浄処理することなく、そのまま汚染の状態と外観とを実施例1と同様にして調べた。
(Comparative Example 4)
The heat treatment jig after the heat treatment was examined in the same manner as in Example 1 for the state of contamination and the appearance without washing.

洗浄・乾燥後の熱処理治具の、汚染の状態と外観を調べた結果を以下に示す。
実施例1; 汚染量 <1 、 外観 問題なし
実施例2; 汚染量 <1 、 外観 問題なし
比較例1; 汚染量 <1 、 外観 エッチングムラ有り
比較例2; 汚染量 100 、 外観 問題なし
比較例3; 汚染量 30 、 外観 色ムラ有り
比較例4; 汚染量 100 、 外観 問題なし
The results of examining the contamination state and appearance of the heat treatment jig after washing and drying are shown below.
Example 1; Contamination Amount <1, Appearance No problem Example 2; Contamination Amount <1, Appearance no problem Comparative Example 1 Contamination Amount <1, Appearance Etching unevenness Comparative Example 2 Contamination Amount 100 Appearance No problem Comparative Example 3; Contamination amount 30, Appearance Color unevenness Comparative example 4; Contamination amount 100, Appearance No problem

以上の結果より、本発明の実施例1、実施例2は、熱処理後汚染量が100の熱処理治具(比較例4)を、汚染量を1未満(<1)にまで洗浄(エッチング)することができ、さらに、外観についても、表面荒れ等の問題がなく、良好に洗浄できることが確認された。   From the above results, in Examples 1 and 2 of the present invention, the heat treatment jig (Comparative Example 4) whose contamination amount after heat treatment is 100 is cleaned (etched) to a contamination amount of less than 1 (<1). In addition, it was confirmed that the appearance can be satisfactorily cleaned without problems such as surface roughness.

Claims (5)

シリコン基板を熱処理する際にこれを保持するために用いられる、シリコンからなる半導体熱処理治具の洗浄方法であって、
洗浄液として、弗酸の配合比が質量比で1%以上8%以下、硝酸の配合比が質量比で35%以上70%以下、水の配合比が質量比で30%以上60%以下に調製された弗酸と硝酸と水との混合液を用い、この洗浄液によって前記のシリコンからなる半導体熱処理治具をエッチングすることで、該半導体熱処理治具を洗浄する洗浄工程を有することを特徴とする半導体熱処理治具の洗浄方法。
A method of cleaning a semiconductor heat treatment jig made of silicon, which is used to hold a silicon substrate when it is heat-treated,
The cleaning liquid is prepared so that the mixing ratio of hydrofluoric acid is 1% to 8% by mass, the mixing ratio of nitric acid is 35% to 70% by mass, and the mixing ratio of water is 30% to 60% by mass. A cleaning step of cleaning the semiconductor heat treatment jig by using the mixed liquid of hydrofluoric acid, nitric acid and water and etching the semiconductor heat treatment jig made of silicon with the cleaning liquid. Cleaning method for semiconductor heat treatment jig.
シリコン基板を熱処理する際にこれを保持するために用いられる、シリコンからなる半導体熱処理治具の洗浄方法であって、
洗浄液として、弗酸の配合比が質量比で1%以上8%以下、硝酸の配合比が質量比で35%以上70%以下、酢酸と水との混合物の配合比が質量比で30%以上60%以下に調製された弗酸と硝酸と酢酸と水との混合液を用い、この洗浄液によって前記のシリコンからなる半導体熱処理治具をエッチングすることで、該半導体熱処理治具を洗浄する洗浄工程を有することを特徴とする半導体熱処理治具の洗浄方法。
A method of cleaning a semiconductor heat treatment jig made of silicon, which is used to hold a silicon substrate when it is heat-treated,
As the cleaning liquid, the mixing ratio of hydrofluoric acid is 1% to 8% by mass, the mixing ratio of nitric acid is 35% to 70% by mass, and the mixture ratio of acetic acid and water is 30% or more by mass. A cleaning process for cleaning the semiconductor heat treatment jig by using a mixed liquid of hydrofluoric acid, nitric acid, acetic acid and water prepared to 60% or less and etching the semiconductor heat treatment jig made of silicon with the cleaning liquid. A method for cleaning a semiconductor heat treatment jig, comprising:
前記洗浄工程の後に、該半導体熱処理治具を、弗酸水溶液に浸漬する弗酸処理工程と、その後、該半導体熱処理治具を水でリンスするリンス工程とを有することを特徴とする請求項1又は2に記載の半導体熱処理治具の洗浄方法。   2. The method according to claim 1, further comprising a hydrofluoric acid treatment step of immersing the semiconductor heat treatment jig in a hydrofluoric acid aqueous solution and a rinsing step of rinsing the semiconductor heat treatment jig with water after the cleaning step. Alternatively, the method for cleaning a semiconductor heat treatment jig according to 2. 前記弗酸水溶液の弗酸の濃度が、質量比で0.5%以上20%以下であることを特徴とする請求項3記載の半導体熱処理治具の洗浄方法。   4. The method for cleaning a semiconductor heat treatment jig according to claim 3, wherein the concentration of hydrofluoric acid in the hydrofluoric acid aqueous solution is 0.5% to 20% by mass ratio. 前記洗浄工程の前に、前記洗浄液を用いてダミーのシリコンを洗浄する、ダミー洗浄工程を有することを特徴とする請求項1〜4のいずれか一項に記載の半導体熱処理治具の洗浄方法。   5. The method for cleaning a semiconductor heat treatment jig according to claim 1, further comprising a dummy cleaning step of cleaning dummy silicon using the cleaning liquid before the cleaning step. 6.
JP2008236410A 2008-09-16 2008-09-16 Method for cleaning semiconductor heat-treating tool Withdrawn JP2010073729A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2008236410A JP2010073729A (en) 2008-09-16 2008-09-16 Method for cleaning semiconductor heat-treating tool

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2008236410A JP2010073729A (en) 2008-09-16 2008-09-16 Method for cleaning semiconductor heat-treating tool

Publications (2)

Publication Number Publication Date
JP2010073729A true JP2010073729A (en) 2010-04-02
JP2010073729A5 JP2010073729A5 (en) 2012-02-09

Family

ID=42205280

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2008236410A Withdrawn JP2010073729A (en) 2008-09-16 2008-09-16 Method for cleaning semiconductor heat-treating tool

Country Status (1)

Country Link
JP (1) JP2010073729A (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10194876A (en) * 1996-12-27 1998-07-28 Sumitomo Metal Ind Ltd Manufacturing method of jig for semiconductor
JP2000082643A (en) * 1999-07-30 2000-03-21 Canon Inc Semiconductor substrate and manufacture thereof
JP2001217219A (en) * 2000-01-31 2001-08-10 Tokyo Electron Ltd Method and device for treating liquid
WO2006080264A1 (en) * 2005-01-27 2006-08-03 Shin-Etsu Handotai Co., Ltd. Method of selective etching and silicon single crystal substrate

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10194876A (en) * 1996-12-27 1998-07-28 Sumitomo Metal Ind Ltd Manufacturing method of jig for semiconductor
JP2000082643A (en) * 1999-07-30 2000-03-21 Canon Inc Semiconductor substrate and manufacture thereof
JP2001217219A (en) * 2000-01-31 2001-08-10 Tokyo Electron Ltd Method and device for treating liquid
WO2006080264A1 (en) * 2005-01-27 2006-08-03 Shin-Etsu Handotai Co., Ltd. Method of selective etching and silicon single crystal substrate

Similar Documents

Publication Publication Date Title
EP1737026B1 (en) Method of surface treating III-V semiconductor compound based substrates and method of manufacturing III-V compound semiconductors
CN108885989A (en) The method and apparatus deposited for handling nitride structure without silica
CN100442442C (en) Manufacturing method of silicon epitaxial wafer
JP2009248021A (en) Cleaning process of silicon boat, silicon boat, heat treating method of silicon wafer, and silicon wafer
WO2005057645A1 (en) Silicon wafer processing method
WO2013179569A1 (en) Method for cleaning semiconductor wafer
JP2018170523A (en) Method for manufacturing silicon wafer
EP1956641A1 (en) Method for grinding surface of semiconductor wafer and method for manufacturing semiconductor wafer
JP2008244434A (en) Method for removing bulk metal contamination from group III-V semiconductor substrates
JP6610443B2 (en) Surface defect inspection method for semiconductor silicon wafer
KR20110036990A (en) Uniform oxide film formation method and cleaning method
JP4552415B2 (en) Method for manufacturing silicon wafer
US20040266191A1 (en) Process for the wet-chemical surface treatment of a semiconductor wafer
JP4857738B2 (en) Semiconductor wafer cleaning method and manufacturing method
JP2010073729A (en) Method for cleaning semiconductor heat-treating tool
TWI615896B (en) 矽 Wafer manufacturing method
JP2024078489A (en) Method for removing device pattern and method for evaluating crystal defect in silicon wafers using the same
JP2011508981A (en) Reduction of watermarks in HF processing of semiconductor substrates
CN116246944A (en) Method for cleaning residual silicon peroxide polishing solution on silicon carbide surface
JP2004343013A (en) Etching method of silicon material
JP6604630B2 (en) Crystal defect evaluation method for low resistance silicon single crystal substrate
JP2008227060A (en) Annealed wafer manufacturing method
KR100823714B1 (en) Cleaning solution for polymer removal and polymer removal method using same
JP2006016460A (en) Cleaning solution for silicon-including substrate and method for cleaning silicon-including substrate
JP2001176862A (en) Silicon wafer, etching liquid and method of etching therefor

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20110916

A521 Written amendment

Effective date: 20110928

Free format text: JAPANESE INTERMEDIATE CODE: A523

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20111216

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20130130

A131 Notification of reasons for refusal

Effective date: 20130212

Free format text: JAPANESE INTERMEDIATE CODE: A131

A761 Written withdrawal of application

Effective date: 20130408

Free format text: JAPANESE INTERMEDIATE CODE: A761