JP2004259828A - Semiconductor exposure system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor exposure system which can prevent decrease of light transmittance of an optical element included in the system which uses an ultraviolet laser beam as the exposing light. <P>SOLUTION: The semiconductor exposure system is equipped with an illumination optical system IS which illuminates a mask M by making a laser beam output from a laser beam source 2 the exposing light, and a projection optical system PL which is stored in a mirror cylinder 22 and forms a pattern image of the mask M on a photosensitive substrate W. Fluorine gas is enclosed in the mirror cylinder 22. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【００６０】
【実施例】
図２に示すチャンバ６０及び支持台５８の材質を純アルミニウムとし、ガス供給管６２及びガス排出管６４の材質を純ニッケルとする。また、ガス供給管６２のバルブ６２ａ及びガス排出管６４のバルブ６４ａの材質をステンレスとするが、フッ素ガスが接する部分にニッケルめっきを施し、フッ素ガスとステンレスが触れないようにする。
【００６１】
フッ素ガスの接する部分を純ニッケルまたは純アルミニウムとした理由は、特願２００２−１９８１６５に記載したように、全元素中で最も反応性の高いフッ素が純ニッケルまたは純アルミニウム以外の金属と反応した場合には揮発性フッ化物が生成される場合が多く、それら揮発性フッ化物が光学素子を汚染する不純物となるためである。例えば、ステンレスとフッ素ガスを接触させた場合には、室温においてさえ反応が進行してＣｒＦ_５ガスを生成する。ＣｒＦ_５ガスは、光学素子に被覆されている光学薄膜表面に吸着したのち、チャンバや露光装置の鏡筒内にわずかに存在するＨ_２Ｏと反応してＣｒ_２Ｏ_３となる。生成されたＣｒ_２Ｏ_３は、光学薄膜表面に固着して、光を吸収する。一方、フッ素はアルミニウムやニッケルとも反応してフッ化アルミニウムやフッ化ニッケルとなるが、これら生成されたフッ化物は不揮発性固体であるため、光学素子を汚染する物質とはなりえない。
【００６２】
まず、蛍石光学素子５４ａ〜５４ｅをチャンバ６０内に装填し、ガス供給管６２よりＨｅガスで１０００ｐｐｍ（０．１パーセント）に希釈済みのフッ素ガスをチャンバ６０内に流通させた。フッ素ガス流通を開始してから充分に時間が経過し、チャンバ６０内のガス雰囲気が安定したところで、ガス排出管６４よりチャンバ６０内流通ガスを少量サンプルリングした。サンプリングしたガスを用いて、レーザ照射前のチャンバ６０内の残留汚染物質成分を分析した。その結果、ガスクロマトグラフ質量分析法で分析した全有機物濃度は１０μｇ／ｍ^３、ＮＨ_３濃度は０．２μｇ／ｍ^３であった。また、酸素および水分濃度計で測定したＨ_２Ｏ、Ｏ_２濃度はいずれも５ｐｐｍ程度であった。
【００６３】
上記ガス雰囲気下において、レーザ照射試験を行った。まず、蛍石光学素子５４ａ〜５４ｅをＦ_２レーザ光が通過しない位置に配置し、ジュールメータ７０に達した光量Ｔ_０を測定し、蛍石光学素子１つ当りの透過率Ｔを数式１を用いて算出した。次に、蛍石光学素子５４ａ〜５４ｅをＦ_２レーザ光が通過する位置に配置し、Ｆ_２レーザ光を所望のドーズ量だけ照射した。再び、ジュールメータ７０に達した光量Ｔ_１を測定し、透過率Ｔを数式１を用いて算出した。以下、同様にして、蛍石光学素子５４ａ〜５４ｅに対して所望のドーズ量のＦ_２レーザ照射を行う毎に、光量Ｔ_１を測定し、数式１を用いて透過率Ｔを算出することを繰り返した。
【００６４】
図４は、Ｆ_２レーザ照射による透過率Ｔの変動の様子を示す図である。Ｆ_２レーザ照射ドーズ量によらず、透過率Ｔが一切変動していないことが容易にわかる。即ち、フッ素雰囲気下でＦ_２レーザ照射を行なえば、有機物やアンモニアが光学薄膜上で固着または重合して光吸収物質が形成することなく、かつ、Ｈ_２Ｏ，Ｏ_２がＦ_２レーザ照射時に膜と反応して酸化物や水酸化物薄層が形成されて光吸収が発生することもない。また、長期にわたるＦ_２レーザ照射によっても光学素子の透過率低下を一切発生させない。
【００６５】
なお、この実施例においては、フッ素ガスを希釈するためにＨｅガスを用いた実験結果を示したが、Ｈｅ、Ｎｅ、Ａｒ、Ｋｒ、Ｘｅ及びＮ_２ガスの少なくとも１つのガスを希釈ガスとして使用しても効果が同じであることを確認した。また、この実施例においては、フッ素ガス濃度１０００ｐｐｍ（０．１パーセント）の実験結果を示したが、フッ素ガス濃度としては０．０００１〜１００パーセントの何れにおいても効果があることを確認した。なお、高い化学反応力を持つフッ素が接ガス部分に及ぼす長期的な腐食影響を考慮すると、フッ素ガス濃度は１パーセント以下とすることが望ましい。一方、フッ素ガス濃度が低濃度すぎると汚染物質の化学的除去効果が不十分となるため、フッ素ガス濃度は１０ｐｐｍ（０．００１パーセント）以上であることが望ましい。なお、ガス排出管６４の後段にフッ素ガス除害用吸着カラム６５を取り付けて、排出ガスを安全かつ低環境負荷とした。
【００６６】
【比較例】
図２に示すチャンバ６０、支持台５８、ガス供給管６２、ガス排出管６４、バルブ６２ａ及び６４ａの材質は全てステンレスとする。蛍石光学素子５４ａ〜５４ｅをチャンバ６０内に装填し、ガス供給管６２よりチャンバ６０内にＮ_２ガスを流通させる。流通を開始してから充分に時間が経過してチャンバ６０内のガス雰囲気が安定したところで、ガス排出管６４よりチャンバ６０内流通ガスを少量サンプルリングした。サンプリングしたガスを用いて、チャンバ６０内の残留汚染物質成分を分析した。その結果、ガスクロマトグラフ質量分析法で分析した全有機物濃度は１０μｇ／ｍ^３、ＮＨ_３濃度は０．２μｇ／ｍ^３であった。また、酸素および水分濃度計で測定したＨ_２Ｏ，Ｏ_２濃度はいずれも５ｐｐｍ程度であった。レーザ照射前の残留ガス成分および濃度は、実施例の場合と全く同一であった。
【００６７】
上記ガス雰囲気下において、レーザ照射試験を行った。図４は、レーザ照射による透過率変動の様子を示す図である。レーザ照射ドーズ量とともに透過率が低下していく様子が示されている。有機物やアンモニアが膜上で固着または重合して光吸収物質を形成し且つＨ_２Ｏ，Ｏ_２がレーザ照射時に膜と反応して酸化物や水酸化物薄層を形成し、光吸収が発生したことが原因である。
【００６８】
【発明の効果】
この発明の半導体露光装置によれば、Ｆ_２レーザに代表される真空紫外光を露光光源に用いる半導体露光装置において、鏡筒内または照明光学系格納容器内をフッ素雰囲気にすることにより、鏡筒内または照明光学系格納容器内に残留する有機物及びアンモニア等の不純物がフッ素雰囲気中のフッ素ガスと化学反応を起こし気化するため、鏡筒または照明光学系格納容器に含まれる光学素子及び光学薄膜への不純物の付着、光学薄膜表面の曇りの発生、光学薄膜表面の酸化または水酸化を防止することができる。また、レーザ光源がフッ素レーザ光源である場合に使用される光学素子及び光学薄膜はフッ化物材料であるため、光学素子及び光学薄膜がフッ素雰囲気中のフッ素ガスと化学反応を起こすことなく、光学素子及び光学薄膜の光透過率の低下を防ぐことができる。
【００６９】
また、この発明の半導体露光装置によれば、鏡筒内または照明光学系格納容器内をフッ素雰囲気にした場合にフッ素雰囲気中のフッ素ガスが鏡筒または照明光学系格納容器の内側表面を形成しているニッケル、ニッケル系合金、モネル、アルミニウム及びアルミニウム系合金等の金属類と化学反応を起こしてフッ化物を生成する。しかしながら、生成されたフッ化物は不揮発性固体であるため、鏡筒に含まれる光学素子及び光学薄膜を汚染する不純物とはなりえない。従って、光学素子及び光学薄膜の光透過率の低下を防ぐことができる。
【００７０】
また、この発明の半導体露光装置によれば、鏡筒内または照明光学系格納容器内に封入されているフッ素ガスまたは汚染物質の濃度に基づいて、フッ素ガスの交換を行なう。従って、時間経過と共にフッ素ガスが減少または汚染物質が増大し光学素子及び光学薄膜の光透過率の低下を招く前に、フッ素ガスの交換を行なうことができ、光学素子及び光学薄膜の光透過率の低下を防ぐことができる。
【００７１】
また、この発明の半導体露光装置によれば、鏡筒内または照明光学系格納容器内のフッ素ガスの濃度を０．０００１パーセントより低濃度とすると、鏡筒内または照明光学系格納容器内の汚染物質の化学的除去効果を十分に得ることができなくなるため、封入するフッ素ガスの濃度を０．０００１〜１００パーセントの何れかに設定する。従って、鏡筒内または照明光学系格納容器内に含まれる光学素子及び光学薄膜への汚染物質の付着を防ぐことができ、光学素子及び光学薄膜の光透過率の低下を防ぐことができる。
【００７２】
また、この発明の半導体露光装置を用いれば、感光基板上に微細回路パターンを焼き付けている最中の光透過率低下や照度ムラの発生を防止することができる。従って、真空紫外光を用いる次世代半導体露光装置の生産性を著しく向上させることができる。
【図面の簡単な説明】
【図１】この発明の実施の形態にかかる半導体露光装置の構成図である。
【図２】この発明の実施の形態にかかるＦ_２レーザ照射実験装置の構成図である。
【図３】この発明の実施の形態にかかるＦ_２レーザ照射実験装置内で支持台が稼動する様子を示す図である。
【図４】この発明の実施例において、蛍石光学素子にＦ_２レーザ照射して透過率Ｔを連続計測した結果を示すグラフである。
【符号の説明】
Ｍ…マスク、ＩＳ…照明光学系、ＰＬ…投影光学系、Ｗ…ウエハ（感光基板）、ＷＳ…ウエハステージ、２…レーザ光源部、４…コリメートレンズ、６…フライアイレンズ、８…σ絞り、１０…ミラー、１２…コンデンサレンズ系、１４…照明光学系格納容器、２０…制御部、２２…鏡筒、１４ａ、２２ａ…フッ素ガス供給部、１４ｂ、２２ｂ…フッ素ガス排出部、１６、２４…フッ素ガス置換装置、１８、２６…フッ素ガス濃度検出器、１９、２８…汚染物質濃度検出器、４０…レーザ照射実験装置、４２…Ｆ_２レーザ発振器、４４…導波管、４８、６８…シャッタ、５０、６６…フッ化物窓、５４ａ〜５４ｅ…蛍石光学素子、５６ａ〜５６ｅ…光学薄膜、５８…支持台、６０…チャンバ、６２…ガス供給管、６４…ガス排出管、６５…フッ素ガス除害用吸着カラム、７０…ジュールメータ。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a semiconductor exposure apparatus using ultraviolet laser light as exposure light.
[0002]
[Prior art]
In recent years, high integration and high density of semiconductor integrated circuits have been advanced. In order to realize higher integration and higher density of the semiconductor integrated circuit, it is necessary to further reduce the line width of the circuit or to further fine the pattern. For this reason, there is a demand for ever-increasing resolution of a reduced projection exposure apparatus for manufacturing a semiconductor circuit.
[0003]
In order to increase the resolution in the exposure apparatus, the wavelength of the exposure light source has been shortened to g-line (wavelength: 436 nm), i-line (wavelength: 365 nm) and KrF excimer laser (wavelength: 248 nm). ArF excimer laser (wavelength 193 nm), F ₂ The laser (wavelength: 157 nm) has been further shortened in wavelength.
[0004]
In a semiconductor exposure apparatus using an ArF excimer laser as an exposure light source, dozens of optical elements of various shapes and uses are arranged between a light source and a wafer, and each optical element surface has a purpose. The corresponding optical thin film is coated. In addition, in the lens barrel storing these optical elements, N ₂ An inert gas such as a gas is circulated.
[0005]
Further, the vacuum ultraviolet wavelength F shorter than the ArF excimer laser is used. ₂ In a semiconductor exposure apparatus using a laser as an exposure light source, quartz glass and all other oxides conventionally used as a lens material absorb light and do not transmit, so that F ₂ CaF with high light transmittance even at the wavelength of laser ₂ Single-crystal fluorite is used as a lens material, and MgF ₂ , AlF ₃ , LaF ₃ , GdF ₃ And the like are used as a film material. Further, He gas or N 2 is contained in the lens barrel in which the optical element and the like are stored. ₂ It has been studied to distribute an inert gas such as a gas.
[0006]
In such a semiconductor exposure apparatus, the installation environment of the exposure apparatus and N ₂ Trace amounts of organic substances and impurities such as ammonia contained in the gas are introduced into the lens barrel, adhere to the thin film on the surface of the optical element, and polymerize or adhere after laser irradiation. As a result, the optical element The light transmittance of the film decreases. In one semiconductor exposure apparatus, all the optical elements to be used are installed in the same lens barrel, so that they are contaminated by impurities present in the lens barrel, and the transmittance is reduced almost equally. Here, assuming that the transmittance of one coated surface of an optical element is T and the transmittance decrease due to contamination is ΔT, the two-sided transmittance of this optical element after contamination is (T−ΔT). ² It becomes. Assuming that the number of all optical elements is n, the transmittance reduction amount in the entire system is (T−ΔT) ²ⁿ It becomes. Accordingly, the amount of exposure light that reaches the wafer through the tens of optical elements from the laser light source and reaches the wafer is fatally small when there is contamination compared to the ideal state where there is no contamination. Would. Of course, efforts are made to minimize the amount of impurities brought into the lens barrel, but it is impossible to completely reduce the amount of impurities. This is a problem that always arises.
[0007]
In addition, since water vapor and oxygen gas absorb and do not transmit vacuum ultraviolet light, H ₂ O, O ₂ The higher the concentration, the lower the overall system transmittance. ₂ In an exposure apparatus using a laser as exposure light, water vapor and oxygen gas contained in an inert gas introduced into the lens barrel are reduced as much as possible, and H remaining in the lens barrel is reduced. ₂ O, O ₂ Needs to be reduced as much as possible. Further, since the optical thin film formed at a relatively low temperature is more porous than the bulk, the area where water vapor and oxygen gas enter the optical thin film through gaps between the films and are adsorbed is large. H ₂ O, O ₂ As the amount of adsorbed in the film increases, the overall transmittance of the exposure apparatus decreases. In addition, H in the membrane ₂ On the O adsorption surface, the fluoride of the film material and the adsorbed H ₂ O reacts chemically to form an oxide thin layer and a hydroxide thin layer on the adsorption surface. Since the thin oxide layer and the thin hydroxide layer absorb vacuum ultraviolet light, the overall system transmittance is further reduced.
[0008]
The inventor has reported that H has been applied to the optical thin film coated on the optical element surface. ₂ O, O ₂ In order to reduce the adsorption area, an application has been filed for an invention for making an optical thin film as dense as possible (Japanese Patent Application No. 2001-218045). Also, H ₂ O, O ₂ The thin film of hydroxide and the thin layer of oxide generated by the adsorption of the compound are returned to the fluoride by a post-fluorination reaction, and the structure of the optical thin film is densified by heat treatment of the optical thin film. ₂ O, O ₂ Also, an application has been filed for an invention in which a decrease in the light transmittance is suppressed as much as possible by drastically reducing the adsorption area such as (Japanese Patent Application No. 2001-264512 and Japanese Patent Application No. 2002-198165).
[0009]
[Problems to be solved by the invention]
In the above-described semiconductor exposure apparatus, when water vapor, oxygen gas, or the like is mixed in the lens barrel, the water vapor or oxygen gas does not absorb and transmit the vacuum ultraviolet light, and the overall system light transmittance is reduced. From the H into the lens barrel ₂ O, O ₂ It is necessary to minimize the intrusion of water vapor and oxygen gas contained in the inert gas flowing through the lens barrel as much as possible.
[0010]
In addition, trace amounts of organic substances and impurities such as ammonia contained in the inert gas are guided into the lens barrel, and are deposited on the optical thin film coated on the surfaces of a plurality of optical elements stored in the lens barrel. It is necessary to solve the problem that impurities such as the organic substance and ammonia adhere and polymerize or fix after laser irradiation, thereby reducing the light transmittance of the optical element.
[0011]
An object of the present invention is to provide a semiconductor exposure apparatus that can prevent a light transmittance of an optical element included in a semiconductor exposure apparatus using ultraviolet laser light as exposure light from decreasing.
[0012]
[Means for Solving the Problems]
A semiconductor exposure apparatus according to claim 1, wherein an illumination optical system for illuminating a mask using light emitted from a laser light source as exposure light, and a pattern image of the mask stored in a lens barrel and formed on a photosensitive substrate. A semiconductor exposure apparatus including a projection optical system, wherein a fluorine gas is sealed in the lens barrel.
[0013]
The semiconductor exposure apparatus according to claim 2 is characterized in that the laser light source is a fluorine laser light source.
[0014]
According to the semiconductor exposure apparatus of the first and second aspects, the interior of the lens barrel in which the projection optical system is stored is made to have a fluorine atmosphere, so that impurities such as organic substances and ammonia remaining in the lens barrel are reduced. Since a chemical reaction occurs with the fluorine gas in the fluorine atmosphere and the gas is vaporized, impurities can be prevented from adhering to the optical element and the optical thin film included in the lens barrel. Further, since the optical element and the optical thin film used when the laser light source is a fluorine laser light source are made of a fluoride material, the optical element and the optical thin film do not cause a chemical reaction with fluorine gas in a fluorine atmosphere, and the optical element and the optical thin film do not react with each other. In addition, it is possible to prevent a decrease in light transmittance of the optical thin film.
[0015]
According to a third aspect of the present invention, in the semiconductor exposure apparatus, a portion at least 20 nm from the inner surface of the lens barrel is formed of at least one of nickel, a nickel-based alloy, monel, aluminum, and an aluminum-based alloy. It is characterized by having.
[0016]
According to the semiconductor exposure apparatus of the third aspect, when the inside of the lens barrel in which the projection optical system is stored is made to have a fluorine atmosphere, the fluorine gas in the fluorine atmosphere forms the inner surface of the lens barrel. Contact with metals such as nickel, nickel-based alloys, monel, aluminum, and aluminum-based alloys to cause a chemical reaction to generate fluoride. However, since the generated fluoride is a nonvolatile solid, it cannot be a contaminant that contaminates the optical element and the optical thin film included in the lens barrel. Therefore, it is possible to prevent a decrease in light transmittance of the optical element and the optical thin film.
[0017]
Further, in the semiconductor exposure apparatus according to the present invention, the lens barrel preferably supplies a fluorine gas into the lens barrel, and supplies a fluorine gas into the lens barrel. A gas discharge section.
[0018]
According to the semiconductor exposure apparatus of the fourth aspect, the fluorine gas sealed in the lens barrel in which the projection optical system is stored can be exchanged. Also, it is possible to prevent a decrease in the light transmittance of the optical element and the optical thin film.
[0019]
Further, the semiconductor exposure apparatus according to claim 5, wherein the lens barrel includes an in-lens fluorine gas concentration detecting unit for detecting a fluorine gas concentration in the lens barrel, and the detecting unit detects the fluorine gas concentration in the lens barrel. When the detected fluorine gas concentration value is smaller than a predetermined value, the fluorine gas sealed in the lens barrel is discharged from the fluorine gas discharge part in the lens barrel, and the fluorine gas supply part in the lens barrel is newly supplied. The present invention is characterized in that a suitable fluorine gas is supplied to exchange the fluorine gas sealed in the lens barrel.
[0020]
According to the semiconductor exposure apparatus of the fifth aspect, the fluorine gas is exchanged based on the concentration of the fluorine gas sealed in the lens barrel in which the projection optical system is stored. Therefore, the fluorine gas can be exchanged before the fluorine gas in the lens barrel decreases with time and the light transmittance of the optical element and the optical thin film decreases, and the light transmittance of the optical element and the optical thin film can be reduced. Drop can be prevented.
[0021]
7. The semiconductor exposure apparatus according to claim 6, further comprising: a contaminant concentration detecting section for detecting the contaminant concentration in the lens barrel, wherein the contaminant detected by the contaminant concentration detecting section in the lens barrel. When the detected concentration value exceeds a predetermined value, the fluorine gas sealed in the lens barrel is discharged from the fluorine gas discharge part in the lens barrel, and new fluorine gas is supplied from the fluorine gas supply part in the lens barrel. It is characterized by supplying and exchanging the fluorine gas sealed in the lens barrel.
[0022]
According to the semiconductor exposure apparatus of the sixth aspect, the fluorine gas sealed in the lens barrel is exchanged based on the concentration of contaminants in the lens barrel in which the projection optical system is stored. Therefore, fluorine gas can be exchanged before the contaminants in the lens barrel increase with time and the light transmittance of the optical element and the optical thin film is reduced, and the light transmittance of the optical element and the optical thin film can be reduced. Drop can be prevented.
[0023]
Further, the semiconductor exposure apparatus according to claim 7 is characterized in that the illumination optical system is stored in an illumination optical system storage container, and the illumination optical system storage container is filled with fluorine gas.
[0024]
According to the semiconductor exposure apparatus of the present invention, by setting the inside of the illumination optical system storage container to a fluorine atmosphere, impurities such as organic substances and ammonia remaining in the illumination optical storage container are reduced to the fluorine gas in the fluorine atmosphere. Since a chemical reaction is caused and vaporized, it is possible to prevent contaminants from adhering to the optical element and the optical thin film included in the illumination optical system storage container. Therefore, it is possible to prevent a decrease in light transmittance of the optical element and the optical thin film.
[0025]
Further, in the semiconductor exposure apparatus according to claim 8, a portion at least up to 20 nm from the inner surface of the illumination optical system housing is made of at least one of nickel, nickel-based alloy, monel, aluminum, and aluminum-based alloy. It is characterized by comprising.
[0026]
According to the semiconductor exposure apparatus of the present invention, when the interior of the illumination optical system storage container is set to a fluorine atmosphere, the fluorine gas in the fluorine atmosphere forms nickel forming the inner surface of the illumination optical system storage container, Contact with nickel-based alloys, monel, aluminum, aluminum-based alloys, etc. to cause a chemical reaction to generate fluoride. However, since the generated fluoride is a nonvolatile solid, it cannot be an impurity that contaminates the optical element and the optical thin film included in the illumination optical system. Therefore, it is possible to prevent a decrease in light transmittance of the optical element and the optical thin film.
[0027]
Further, in the semiconductor exposure apparatus according to claim 9, the illumination optical system storage container supplies a fluorine gas into the illumination optical system storage container, and a fluorine gas supply unit in the storage container. A fluorine gas discharge section in a storage container for discharging fluorine gas.
[0028]
According to the semiconductor exposure apparatus of the ninth aspect, since the fluorine gas sealed in the illumination optical system storage container can be exchanged, even when the exposure apparatus is operated for a long time, the optical element and A decrease in light transmittance of the optical thin film can be prevented.
[0029]
Further, the semiconductor exposure apparatus according to claim 10 includes a storage container fluorine gas concentration detection unit that detects a fluorine gas concentration in the illumination optical system storage container, and is detected by the storage container fluorine gas concentration detection unit. When the detected fluorine gas concentration value is smaller than a predetermined value, when the illumination optical system is stored from the fluorine gas discharge unit in the storage container when the fluorine optical gas is discharged from the storage container fluorine gas discharge unit into the illumination optical system storage container. Exchanging the fluorine gas sealed in the illumination optical system storage container by discharging the fluorine gas sealed in the container and supplying new fluorine gas from the storage container fluorine gas supply unit. It is characterized by.
[0030]
According to the semiconductor exposure apparatus of the tenth aspect, the fluorine gas is exchanged based on the concentration of the fluorine gas sealed in the illumination optical system storage container. Therefore, the fluorine gas can be exchanged before the fluorine gas in the storage container for the illumination optical system decreases with time and the light transmittance of the optical element and the optical thin film is reduced, and the light of the optical element and the optical thin film can be exchanged. A decrease in transmittance can be prevented.
[0031]
The semiconductor exposure apparatus according to claim 11 further includes a contaminant concentration detector in the storage container that detects a contaminant concentration in the illumination optical system storage container, and the concentration is detected by the contaminant concentration detector in the storage container. When the detected contaminant concentration value exceeds a predetermined value, the fluorine gas sealed in the illumination optical system storage container is discharged from the fluorine gas discharge unit in the storage container, and the fluorine gas supply unit in the storage container is discharged. A new fluorine gas is supplied to replace the fluorine gas enclosed in the illumination optical system storage container.
[0032]
According to the semiconductor exposure apparatus of the eleventh aspect, the fluorine gas sealed in the illumination optical system storage container is exchanged based on the concentration of the contaminant in the illumination optical system storage container. Therefore, the fluorine gas can be exchanged before the contaminants in the illumination optical system storage container increase with time and the light transmittance of the optical element and the optical thin film decreases, and the light of the optical element and the optical thin film can be changed. A decrease in transmittance can be prevented.
[0033]
Further, in the semiconductor exposure apparatus according to the twelfth aspect, the concentration of the fluorine gas sealed in the lens barrel or the housing of the illumination optical system is 0.0001 to 100%, and the concentration of the helium gas, neon gas, argon gas, At least one of krypton gas, xenon gas and nitrogen gas is used as a diluent gas.
[0034]
According to the semiconductor exposure apparatus of the twelfth aspect, when the concentration of fluorine gas in the lens barrel in which the projection optical system is stored or in the storage container of the illumination optical system is lower than 0.0001%, Since the effect of chemically removing contaminants inside or inside the illumination optical system storage container cannot be sufficiently obtained, the concentration of the fluorine gas to be enclosed is set to any of 0.0001 to 100%. Therefore, it is possible to prevent contaminants from adhering to the optical element and the optical thin film included in the lens barrel or the illumination optical system storage container, and to prevent a decrease in light transmittance of the optical element and the optical thin film.
[0035]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a semiconductor exposure apparatus according to this embodiment.
[0036]
The semiconductor exposure apparatus shown in FIG. 1 includes an illumination optical system IS for illuminating a mask M, a projection optical system PL for forming a pattern image of the mask M, and a wafer (photosensitive) coated with a photosensitive resin such as a photoresist. And a wafer swage WS for holding the wafer W. Here, the illumination optical system IS is a vacuum ultraviolet light F ₂ It is composed of a laser light source unit 2 for supplying laser light (fluorine laser light, wavelength of 157 nm), a collimator lens 4, a fly-eye lens 6 as an optical integrator, a σ stop 8, a mirror 10, a condenser lens system 12, and the like. The exposure light supplied from the optical system IS illuminates the mask M. The pattern image of the mask M is projected and exposed on a wafer W coated with a photoresist via a projection optical system PL. Note that F ₂ Instead of the laser light source unit 2 that supplies laser light, a laser light source unit that supplies ArF excimer laser light (argon fluoride excimer laser light, wavelength 193 nm) that is deep ultraviolet light may be used.
[0037]
Here, the illumination optical system IS and the mask M are housed in the illumination optical system storage container 14 which is a closed space. Here, the illumination optical system housing 14 is made of at least one of nickel, a nickel-based alloy, monel, aluminum, and an aluminum-based alloy. Note that the illumination optical system storage container 14 may be configured such that a portion at least 20 nm from the inner surface is made of at least one of nickel, a nickel-based alloy, monel, aluminum, and an aluminum-based alloy.
[0038]
When the material of the illumination optical containment container 14 is a metal other than nickel, a nickel-based alloy, monel, aluminum and an aluminum-based alloy, the fluorine gas comes into contact with the fluorine gas and reacts with the fluorine gas to generate volatile fluoride. Since these volatile fluorides become impurities that contaminate the optical elements contained in the illumination optical system container 14, the material of the illumination optical system container 14 is made of nickel, nickel-based alloy, monel, aluminum, and aluminum-based alloy. At least one of them. That is, when stainless steel and fluorine gas are brought into contact, the reaction proceeds and CrF ₅ Generate gas. CrF ₅ After the gas is adsorbed on the surface of the optical thin film coated on the optical element, the H slightly present in the illumination optical system housing 14 is removed. ₂ Reacts with O and Cr ₂ O ₃ It becomes. Generated Cr ₂ O ₃ Adheres to the surface of the optical thin film and absorbs light. On the other hand, fluorine also reacts with aluminum and nickel to form aluminum fluoride and nickel fluoride. Since the generated fluoride is a non-volatile solid, it contaminates the optical element contained in the illumination optical system housing 14. It cannot be a substance to do.
[0039]
Further, the illumination optical system storage container 14 is filled with fluorine gas. The concentration of the fluorine gas to be enclosed is set to 0.0001 to 100%, and He (helium) gas, Ne (neon) gas, Ar (argon) gas, Kr (krypton) gas, Xe (xenon) gas and N ₂ At least one of the (nitrogen) gases is used as a dilution gas.
[0040]
Further, a fluorine gas replacement device 16 in the storage container is connected to the illumination optical system storage container 14. The illumination optical system storage container 14 is configured so that fluorine gas is supplied from the storage container fluorine gas supply unit 14a by the storage container fluorine gas replacement device 16 and fluorine gas is discharged from the storage container fluorine gas discharge unit 14b. Have been. When replacing the fluorine gas in the illumination optical system storage container 14, the fluorine gas replacement device 16 in the storage container removes the fluorine gas in the storage container in order to discharge the fluorine gas safely and with a low environmental load. A harmful adsorption column (not shown) is provided.
[0041]
Further, the illumination optical system storage container 14 is connected to a fluorine gas concentration detector 18 in the storage container and a contaminant concentration detector 19 in the storage container. Fluorescent gas concentration detected value in the illumination optical system storage container 14 detected by the fluorine gas concentration detector 18 in the storage container, and pollutant in the illumination optical system storage container 14 detected by the contaminant concentration detector 19 in the storage container. The density detection value is output to the control unit 20. Here, the contaminants are generated by the installation environment of the exposure apparatus, or include organic substances, impurities such as ammonia, water vapor, oxygen gas, and the like contained in the gas sealed in the illumination optical system container 14. That is.
[0042]
The control unit 20 determines whether or not the detected value of the fluorine gas concentration in the illumination optical system storage container 14 output from the storage container fluorine gas concentration detector 18 is smaller than a predetermined value. When it is determined that the detected value of the concentration of fluorine gas in the illumination optical system storage container 14 is smaller than a predetermined value, the control unit 20 outputs a control signal to the storage container fluorine gas replacement device 16. By discharging the fluorine gas sealed in the illumination optical system storage container 14 from the fluorine gas discharge portion 14b in the storage container and supplying new fluorine gas from the fluorine gas supply portion 14a in the storage container, the illumination optical system is stored. The fluorine gas in the container 14 is exchanged.
[0043]
Further, the control unit 20 determines whether or not the detected value of the concentration of the contaminant in the storage container 14 of the illumination optical system output from the concentration detector 19 of the contaminant in the storage container is larger than a predetermined value. If it is determined that the detected value of the contaminant concentration in the illumination optical system storage container 14 is larger than the predetermined value, the control unit 20 outputs a control signal to the storage container fluorine gas replacement device 16. By discharging the fluorine gas sealed in the illumination optical system storage container 14 from the fluorine gas discharge portion 14b in the storage container and supplying new fluorine gas from the fluorine gas supply portion 14a in the storage container, the illumination optical system is stored. The fluorine gas in the container 14 is exchanged.
[0044]
Further, the projection optical system PL, the wafer W, and the wafer stage WS are housed in a lens barrel 22 which is a closed space. Here, the lens barrel 22 is made of at least one of nickel, a nickel-based alloy, Monel, aluminum, and an aluminum-based alloy. It is sufficient that the lens barrel 22 has a portion at least 20 nm from the inner surface made of at least one of nickel, nickel-based alloy, monel, aluminum, and aluminum-based alloy.
[0045]
When the material of the lens barrel 22 is a metal other than nickel, a nickel-based alloy, monel, aluminum and an aluminum-based alloy, the fluorine gas comes into contact with the fluorine gas and reacts with the fluorine gas to generate volatile fluorides. Since the crystalline fluoride becomes an impurity contaminating the optical element contained in the lens barrel 22, the material of the lens barrel 22 is at least one of nickel, nickel-based alloy, monel, aluminum, and aluminum-based alloy. That is, when stainless steel and fluorine gas are brought into contact, the reaction proceeds and CrF ₅ Generate gas. CrF ₅ After the gas is adsorbed on the surface of the optical thin film coated on the optical element, the H ₂ Reacts with O and Cr ₂ O ₃ It becomes. Generated Cr ₂ O ₃ Adheres to the surface of the optical thin film and absorbs light. On the other hand, fluorine also reacts with aluminum and nickel to form aluminum fluoride and nickel fluoride. Since the generated fluoride is a non-volatile solid, it is a substance that pollutes the optical element contained in the lens barrel 22. Can not be.
[0046]
The lens barrel 22 is filled with fluorine gas. The concentration of the fluorine gas to be sealed is set to 0.0001 to 100%, and He gas, Ne gas, Ar gas, Kr gas, Xe gas and N gas are used. ₂ At least one of the gases is used as a diluent gas.
[0047]
The lens barrel 22 is connected to a fluorine gas replacement device 24 in the lens barrel. The lens barrel 22 is configured such that fluorine gas is supplied from the fluorine gas supply part 22a in the lens barrel and fluorine gas is discharged from the fluorine gas discharge part 22b in the lens barrel by the fluorine gas replacement device 24 in the lens barrel. I have. The fluorine gas replacement device 24 in the lens barrel is used to remove fluorine gas in the lens barrel 22 in order to discharge fluorine gas safely and with a low environmental load when replacing fluorine gas in the lens barrel 22. A column (not shown) is provided.
[0048]
The lens barrel 22 is connected with a fluorine gas concentration detector 26 in the lens barrel and a pollutant detector 28 in the lens barrel. The detected value of the fluorine gas concentration in the lens barrel 22 detected by the fluorine gas concentration detector 26 in the lens barrel and the detected value of the pollutant concentration in the lens barrel 22 detected by the pollutant detector 28 in the lens barrel are controlled by the control unit. 20 is output. Here, the contaminants are organic substances, impurities such as ammonia, water vapor, oxygen gas, and the like generated by the installation environment of the exposure apparatus or contained in a gas sealed in the lens barrel 22. .
[0049]
The control unit 20 determines whether or not the detected value of the concentration of fluorine gas in the lens barrel 22 output from the concentration of fluorine gas detector 26 in the lens barrel is smaller than a predetermined value. When it is determined that the detected value of the concentration of fluorine gas in the lens barrel 22 is smaller than the predetermined value, the control unit 20 outputs a control signal to the fluorine gas replacement device 24 in the lens barrel, and The fluorine gas in the lens barrel 22 is exchanged by discharging the fluorine gas in the lens barrel 22 from the fluorine gas discharge part 22b and supplying new fluorine gas from the fluorine gas supply part 24a in the lens barrel.
[0050]
Further, the control unit 20 determines whether or not the detected value of the contaminant concentration in the lens barrel 22 output from the in-lens contaminant concentration detector 28 exceeds a predetermined value. When it is determined that the detected value of the contaminant concentration in the lens barrel 22 exceeds a predetermined value, the control unit 20 outputs a control signal to the fluorine gas replacing device 24 in the lens barrel, The fluorine gas in the lens barrel 22 is exchanged by discharging the fluorine gas in the lens barrel 22 from the in-cylinder fluorine gas discharge unit 22b and supplying new fluorine gas from the in-cylinder fluorine gas supply unit 24a.
[0051]
According to the semiconductor exposure apparatus of this embodiment, fluorine gas is sealed in the illumination optical system storage container and the lens barrel. Therefore, F ₂ Even when the optical element and the optical thin film used in the exposure apparatus using laser light as an exposure light source are made of a fluoride material, impurities such as organic substances and ammonia in the illumination optical system storage container and the lens barrel may be fluorine gas. This causes a chemical reaction and vaporization, thereby preventing impurities from adhering to the optical element and the optical thin film.
[0052]
Further, when the concentration of fluorine gas in the illumination optical system storage container and the lens barrel decreases due to a chemical reaction between impurities such as organic substances and ammonia and fluorine gas with time, or in the illumination optical system storage container and the lens barrel Even when contaminants such as water vapor and oxygen gas increase, the concentration of the fluorine gas in the illumination optical system housing and the lens barrel and the concentration of the contaminants in the illumination optical system housing and the lens barrel can be reduced. In addition, since the fluorine gas is exchanged in the housing for the illumination optical system and in the lens barrel, it is possible to prevent a decrease in light transmittance of the optical element and the optical thin film.
[0053]
In the above-described embodiment, the replacement of the fluorine gas in the illumination optical system storage container or the lens barrel is performed based on the detection value detected by the fluorine gas concentration detector or the contaminant concentration detector. The flow of fluorine gas may be continued without using a fluorine gas concentration detector or a pollutant concentration detector.
[0054]
In the exposure apparatus according to this embodiment, it was confirmed by experiments using an irradiation experiment apparatus described below that the light transmittance of the optical members constituting the projection optical system and the illumination optical system did not decrease.
[0055]
FIG. 2 is a diagram showing a configuration of the laser irradiation experiment device 40. As shown in FIG. 2, in the laser irradiation experiment device 40, F ₂ F emitted from the laser oscillator 42 into the waveguide 44 ₂ The laser beam 46 passes through a shutter 48 that can be opened and closed and a fluoride window 50, and further passes through five fluorite optical elements 54a, 54b, 54c, 54d, and 54e in order. Here, the five fluorite optical elements 54a to 54e shown in FIG. 2 have optical thin films 56a, 56b, 56c, 56d, and 56e laminated on both surfaces thereof, respectively, and are mounted on a movable support base 58. I have. The fluorite optical elements 54a to 54e and the support 58 are arranged in a chamber 60 which is a closed space. Fluorine gas is sealed in the chamber 60, and a gas supply pipe 62 having an openable / closable valve 62a and a gas discharge pipe 64 having an openable / closable valve 64a are connected. The light beam transmitted through the five optical elements 54a to 54e passes through the fluoride window 66 and the shutter 68 that can be opened and closed, and reaches the joule meter 70.
[0056]
In the laser irradiation experiment apparatus 40, laser irradiation can be performed by changing the gas environment, gas concentration, and contaminant concentration enclosed in the chamber 60 in which the fluorite optical elements 54a to 54e are stored. In addition, it is possible to measure transmittance fluctuations for the fluorite optical elements 54a to 54e. Therefore, the same result as in the case where the optical element such as a lens, a prism, or a mirror is stored in the illumination optical system storage container or the lens barrel of the exposure apparatus according to this embodiment and the fluorine gas is sealed can be obtained. .
[0057]
FIG. 3 is a diagram showing a state in which the support base 58 on which the fluorite optical elements 54a to 54e are mounted is moved in the chamber 60. By moving the support 58, the fluorite optical elements 54a to 54e ₂ It can be placed at a position where laser light does not pass, ₂ It can be arranged at a position where laser light passes.
[0058]
First, the fluorite optical elements 54a to 54e are ₂ It is arranged at a position where laser light does not pass. That is, F ₂ The laser beam is not transmitted through the fluorite optical elements 54a to 54e, and the light amount T of the light reaching the joule meter 70 is set. ₀ Is measured. Next, the fluorite optical elements 54a to 54e are ₂ It is arranged at the position where the laser light passes. That is, F ₂ The laser light is transmitted through the fluorite optical elements 54a to 54e, and the light amount T of the light reaching the joule meter 70 is set. ₁ Is measured. Since the number of fluorite optical elements through which laser light passes by laser irradiation is five, the transmittance T per one optical element can be calculated by Expression 1.
[0059]
[Formula 1]

[0060]
【Example】
The material of the chamber 60 and the support 58 shown in FIG. 2 is pure aluminum, and the material of the gas supply pipe 62 and the gas discharge pipe 64 is pure nickel. The material of the valve 62a of the gas supply pipe 62 and the valve 64a of the gas discharge pipe 64 is made of stainless steel, but nickel plating is applied to a portion where the fluorine gas contacts, so that the fluorine gas does not come into contact with the stainless steel.
[0061]
The reason for contacting the fluorine gas with pure nickel or pure aluminum is that, as described in Japanese Patent Application No. 2002-198165, the most reactive fluorine among all the elements reacts with a metal other than pure nickel or pure aluminum. In many cases, volatile fluorides are generated, and these volatile fluorides become impurities that contaminate the optical element. For example, when stainless steel and fluorine gas are brought into contact, the reaction proceeds even at room temperature and CrF ₅ Generate gas. CrF ₅ After the gas is adsorbed on the surface of the optical thin film coated on the optical element, a slight amount of H gas is present in the chamber or the barrel of the exposure apparatus. ₂ Reacts with O and Cr ₂ O ₃ It becomes. Generated Cr ₂ O ₃ Adheres to the surface of the optical thin film and absorbs light. On the other hand, fluorine also reacts with aluminum and nickel to form aluminum fluoride and nickel fluoride. However, since the generated fluoride is a nonvolatile solid, it cannot be a substance that contaminates the optical element.
[0062]
First, the fluorite optical elements 54 a to 54 e were loaded into the chamber 60, and fluorine gas diluted to 1000 ppm (0.1%) with He gas from the gas supply pipe 62 was allowed to flow through the chamber 60. When a sufficient time had elapsed since the start of the flow of the fluorine gas and the gas atmosphere in the chamber 60 was stabilized, a small amount of gas flowing through the chamber 60 was sampled from the gas discharge pipe 64. Using the sampled gas, a residual contaminant component in the chamber 60 before the laser irradiation was analyzed. As a result, the total organic matter concentration analyzed by gas chromatography / mass spectrometry was 10 μg / m ³ , NH ₃ The concentration is 0.2 μg / m ³ Met. In addition, H measured with an oxygen and moisture concentration meter ₂ O, O ₂ The concentrations were all about 5 ppm.
[0063]
A laser irradiation test was performed in the above gas atmosphere. First, the fluorite optical elements 54a to 54e are ₂ The light amount T that reaches the joule meter 70 when the laser light is ₀ Was measured, and the transmittance T per one fluorite optical element was calculated using Expression 1. Next, the fluorite optical elements 54a to 54e are ₂ Arranged at a position where laser light passes, F ₂ The laser beam was irradiated by a desired dose. Again, the light amount T that has reached the joule meter 70 ₁ Was measured, and the transmittance T was calculated using Equation 1. Hereinafter, similarly, a desired dose of F is applied to the fluorite optical elements 54a to 54e. ₂ Each time laser irradiation is performed, the light amount T ₁ Was measured, and the calculation of the transmittance T using Equation 1 was repeated.
[0064]
FIG. ₂ FIG. 4 is a diagram illustrating a state of a change in transmittance T due to laser irradiation. F ₂ It is easily understood that the transmittance T does not change at all irrespective of the laser irradiation dose. That is, in a fluorine atmosphere, F ₂ When laser irradiation is performed, organic substances and ammonia are not fixed or polymerized on the optical thin film to form a light-absorbing substance, and H ₂ O, O ₂ Is F ₂ There is no occurrence of light absorption due to formation of a thin oxide or hydroxide layer by reaction with the film during laser irradiation. Also, long-term F ₂ The laser irradiation does not cause any decrease in the transmittance of the optical element.
[0065]
In this example, the experimental results using He gas for diluting the fluorine gas were shown, but He, Ne, Ar, Kr, Xe and N ₂ It was confirmed that the effect was the same even if at least one of the gases was used as the diluent gas. Further, in this example, although the experimental results at a fluorine gas concentration of 1000 ppm (0.1%) were shown, it was confirmed that the effect was obtained at any fluorine gas concentration of 0.0001 to 100%. Considering the long-term corrosion effect of fluorine having a high chemical reaction force on gas contact parts, the fluorine gas concentration is desirably 1% or less. On the other hand, if the fluorine gas concentration is too low, the effect of chemically removing contaminants will be insufficient, so the fluorine gas concentration is desirably 10 ppm (0.001%) or more. In addition, an adsorption column 65 for detoxifying fluorine gas was attached to the subsequent stage of the gas exhaust pipe 64, and the exhaust gas was made safe and had a low environmental load.
[0066]
[Comparative example]
The chamber 60, the support 58, the gas supply pipe 62, the gas exhaust pipe 64, and the valves 62a and 64a shown in FIG. 2 are all made of stainless steel. The fluorite optical elements 54a to 54e are loaded into the chamber 60, and N is introduced into the chamber 60 from the gas supply pipe 62. ₂ Distribute gas. When a sufficient time had passed since the start of the circulation and the gas atmosphere in the chamber 60 was stabilized, a small amount of gas flowing through the chamber 60 was sampled from the gas discharge pipe 64. The residual contaminant components in the chamber 60 were analyzed using the sampled gas. As a result, the total organic matter concentration analyzed by gas chromatography / mass spectrometry was 10 μg / m ³ , NH ₃ The concentration is 0.2 μg / m ³ Met. In addition, H measured with an oxygen and moisture concentration meter ₂ O, O ₂ The concentrations were all about 5 ppm. The residual gas components and concentrations before laser irradiation were exactly the same as in the example.
[0067]
A laser irradiation test was performed in the above gas atmosphere. FIG. 4 is a diagram showing a state of a change in transmittance due to laser irradiation. It is shown that the transmittance decreases with the laser irradiation dose. Organic substances and ammonia are fixed or polymerized on the film to form a light absorbing substance, and H ₂ O, O ₂ Reacts with the film during laser irradiation to form a thin oxide or hydroxide layer, which causes light absorption.
[0068]
【The invention's effect】
According to the semiconductor exposure apparatus of the present invention, F ₂ In a semiconductor exposure apparatus using vacuum ultraviolet light typified by a laser as an exposure light source, an organic substance remaining in the lens barrel or the illumination optical system storage vessel by setting the inside of the lens barrel or the illumination optical system storage vessel to a fluorine atmosphere. And impurities such as ammonia cause a chemical reaction with the fluorine gas in the fluorine atmosphere and vaporize, so that impurities adhere to the optical element and optical thin film contained in the lens barrel or the housing of the illumination optical system, and the surface of the optical thin film becomes cloudy. In addition, oxidation or hydroxylation of the optical thin film surface can be prevented. Further, since the optical element and the optical thin film used when the laser light source is a fluorine laser light source are made of a fluoride material, the optical element and the optical thin film do not cause a chemical reaction with fluorine gas in a fluorine atmosphere, and the optical element and the optical thin film do not react with each other. In addition, it is possible to prevent a decrease in light transmittance of the optical thin film.
[0069]
Further, according to the semiconductor exposure apparatus of the present invention, when the inside of the lens barrel or the illumination optical system storage container is set to the fluorine atmosphere, the fluorine gas in the fluorine atmosphere forms the inner surface of the lens barrel or the illumination optical system storage container. Chemical reaction with metals such as nickel, nickel-based alloys, monel, aluminum and aluminum-based alloys to produce fluorides. However, since the generated fluoride is a nonvolatile solid, it cannot be an impurity that contaminates the optical element and the optical thin film included in the lens barrel. Therefore, it is possible to prevent a decrease in light transmittance of the optical element and the optical thin film.
[0070]
Further, according to the semiconductor exposure apparatus of the present invention, the fluorine gas is exchanged based on the concentration of the fluorine gas or the contaminant sealed in the lens barrel or the housing for the illumination optical system. Therefore, the fluorine gas can be exchanged before the fluorine gas is reduced or the contaminants increase with the passage of time and the light transmittance of the optical element and the optical thin film is reduced, and the light transmittance of the optical element and the optical thin film is reduced. Can be prevented from decreasing.
[0071]
Further, according to the semiconductor exposure apparatus of the present invention, if the concentration of fluorine gas in the lens barrel or the illumination optical system container is lower than 0.0001%, the contamination in the lens barrel or the illumination optical system container can be reduced. Since the effect of chemically removing the substance cannot be sufficiently obtained, the concentration of the fluorine gas to be sealed is set to any of 0.0001 to 100%. Therefore, it is possible to prevent contaminants from adhering to the optical element and the optical thin film included in the lens barrel or the illumination optical system storage container, and to prevent a decrease in light transmittance of the optical element and the optical thin film.
[0072]
Further, by using the semiconductor exposure apparatus of the present invention, it is possible to prevent a decrease in light transmittance and an occurrence of uneven illuminance during printing of a fine circuit pattern on a photosensitive substrate. Therefore, the productivity of a next-generation semiconductor exposure apparatus using vacuum ultraviolet light can be significantly improved.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a semiconductor exposure apparatus according to an embodiment of the present invention.
FIG. 2 shows an F according to the embodiment of the present invention. ₂ It is a block diagram of a laser irradiation experiment apparatus.
FIG. 3 is a diagram showing an F according to an embodiment of the present invention; ₂ It is a figure showing signs that a support stand operates in a laser irradiation experiment device.
FIG. 4 shows an embodiment of the present invention in which a fluorite optical element is provided with F ₂ It is a graph which shows the result of having continuously measured the transmittance | permeability T by laser irradiation.
[Explanation of symbols]
M: mask, IS: illumination optical system, PL: projection optical system, W: wafer (photosensitive substrate), WS: wafer stage, 2: laser light source unit, 4: collimating lens, 6: fly-eye lens, 8: σ stop Reference numeral 10: mirror, 12: condenser lens system, 14: illumination optical system storage container, 20: control unit, 22: lens barrel, 14a, 22a: fluorine gas supply unit, 14b, 22b: fluorine gas discharge unit, 16, 24 ... Fluorine gas replacement device, 18, 26 ... Fluorine gas concentration detector, 19,28 ... Pollutant concentration detector, 40 ... Laser irradiation experiment device, 42 ... F ₂ Laser oscillator, 44 waveguide, 48, 68 shutter, 50, 66 fluoride window, 54a to 54e fluorite optical element, 56a to 56e optical thin film, 58 support, 60 chamber, 62 Gas supply pipe, 64: gas exhaust pipe, 65: adsorption column for detoxifying fluorine gas, 70: Joule meter.

Claims (12)

An illumination optical system that illuminates a mask with light emitted from a laser light source as exposure light,
A projection optical system that is stored in a lens barrel and forms a pattern image of the mask on a photosensitive substrate;
A semiconductor exposure apparatus comprising:
A semiconductor exposure apparatus, wherein a fluorine gas is sealed in the lens barrel. The semiconductor exposure apparatus according to claim 1, wherein the laser light source is a fluorine laser light source. 3. The device according to claim 1, wherein a portion at least 20 nm from the inner surface of the lens barrel is made of at least one of nickel, nickel-based alloy, monel, aluminum, and aluminum-based alloy. 6. The semiconductor exposure apparatus according to claim 1. The lens barrel is a fluorine gas supply unit in the lens barrel that supplies fluorine gas into the lens barrel,
An in-barrel fluorine gas discharge unit for discharging fluorine gas in the barrel,
The semiconductor exposure apparatus according to claim 1, further comprising: The lens barrel includes a fluorine gas concentration detector in the lens barrel that detects a fluorine gas concentration in the lens barrel,
When the fluorine gas concentration detection value detected by the fluorine gas concentration detection unit in the lens barrel is smaller than a predetermined value, the fluorine gas sealed in the lens barrel is discharged from the fluorine gas discharge unit in the lens barrel. 5. The apparatus according to claim 1, wherein a new fluorine gas is supplied from the fluorine gas supply unit in the lens barrel to replace the fluorine gas sealed in the lens barrel. 6. Item 6. A semiconductor exposure apparatus according to item 1. A contaminant concentration detector in the lens barrel for detecting a contaminant concentration in the lens barrel,
When the contaminant concentration detection value detected by the contaminant concentration detection unit in the lens barrel exceeds a predetermined value, the fluorine gas sealed in the lens barrel is discharged from the fluorine gas discharge part in the lens barrel. 5. The apparatus according to claim 1, wherein a new fluorine gas is supplied from the fluorine gas supply unit in the lens barrel to replace the fluorine gas sealed in the lens barrel. 6. Item 6. A semiconductor exposure apparatus according to item 1. 7. The illumination optical system according to claim 1, wherein the illumination optical system is stored in an illumination optical system storage container, and the illumination optical system storage container is filled with fluorine gas. The semiconductor exposure apparatus according to claim 1. 8. The apparatus according to claim 7, wherein a portion of the illumination optical system housing from the inner surface to at least 20 nm is made of at least one of nickel, nickel-based alloy, monel, aluminum, and aluminum-based alloy. The semiconductor exposure apparatus according to claim 1. The illumination optical system storage container, a fluorine gas supply unit in the storage container for supplying a fluorine gas into the illumination optical system storage container,
A fluorine gas discharge unit in the storage container for discharging fluorine gas in the illumination optical system storage container,
The semiconductor exposure apparatus according to claim 7, further comprising: The illumination optical system includes a fluorine gas concentration detection unit in the storage container for detecting the fluorine gas concentration in the storage container,
When the fluorine gas concentration detection value detected by the fluorine gas concentration detection unit in the storage container is smaller than a predetermined value, the fluorine gas sealed in the illumination optical system storage container from the fluorine gas discharge unit in the storage container. And supplying a new fluorine gas from the fluorine gas supply unit in the storage container to exchange the fluorine gas sealed in the storage container for the illumination optical system. Item 10. The semiconductor exposure apparatus according to any one of items 9. A contaminant concentration detector for detecting a contaminant concentration in the illumination optical system storage container,
When the contaminant concentration detection value detected by the contaminant concentration detection unit in the storage container exceeds a predetermined value, the fluorine gas sealed in the illumination optical system storage container from the storage container fluorine gas discharge unit. And supplying a new fluorine gas from the fluorine gas supply unit in the storage container to exchange the fluorine gas sealed in the storage container for the illumination optical system. Item 10. The semiconductor exposure apparatus according to any one of items 9. The concentration of the fluorine gas sealed in the lens barrel or the housing for the illumination optical system is 0.0001 to 100%, and at least one of helium gas, neon gas, argon gas, krypton gas, xenon gas and nitrogen gas is used. The semiconductor exposure apparatus according to claim 1, wherein one gas is used as a diluting gas.

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