JP2001114530A - Silica glass optical material for excimer laser and excimer lamp - Google Patents

Silica glass optical material for excimer laser and excimer lamp

Info

Publication number
JP2001114530A
JP2001114530A JP2000084024A JP2000084024A JP2001114530A JP 2001114530 A JP2001114530 A JP 2001114530A JP 2000084024 A JP2000084024 A JP 2000084024A JP 2000084024 A JP2000084024 A JP 2000084024A JP 2001114530 A JP2001114530 A JP 2001114530A
Authority
JP
Japan
Prior art keywords
optical material
silica glass
glass optical
concentration
excimer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP2000084024A
Other languages
Japanese (ja)
Other versions
JP3472234B2 (en
Inventor
Shigeru Yamagata
茂 山形
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.)
Shin Etsu Quartz Products Co Ltd
Original Assignee
Shin Etsu Quartz Products Co Ltd
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
Priority claimed from JP11296101A external-priority patent/JP3069562B1/en
Application filed by Shin Etsu Quartz Products Co Ltd filed Critical Shin Etsu Quartz Products Co Ltd
Priority to JP2000084024A priority Critical patent/JP3472234B2/en
Publication of JP2001114530A publication Critical patent/JP2001114530A/en
Application granted granted Critical
Publication of JP3472234B2 publication Critical patent/JP3472234B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Landscapes

  • Glass Compositions (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide a silica glass optical material that has high initial transmission to the excimer laser or excimer lamp of 155-195 nm wavelengths and a small fluctuation range in the refractive index (Δn) and shows excellent durability under irradiation therewith. SOLUTION: This invention relates to a silica glass optical material for the rays or beams from an Eximer laser and Excimer lamp and characteristically has the following physical and chemical properties: this silica glass optical glass is ultra-high pure, has an OH group contento f 1-100 wt.ppm, a H2 content of 5×1016-5×1019 molecules/cm3, and a F content of 10-10,000 wt.ppm, substantially no content of halogens other than F and a fluctuation range in the refractive index (Δn) of 3×10-6-3×10-7.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【産業上の利用分野】本発明は、シリカガラス光学材料
に関し、特に、波長155〜195nmのエキシマレーザ及びエ
キシマランプを光源とする光線用のシリカガラス光学材
料及びその製造方法に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silica glass optical material, and more particularly to a silica glass optical material for a light beam using an excimer laser having a wavelength of 155 to 195 nm and an excimer lamp, and a method for producing the same.

【0002】[0002]

【従来の技術】上記のようなシリカガラス光学材料は、
波長155〜195nmのエキシマレーザ装置及びエキシマラン
プを光源とする光洗浄用照射装置、集積回路作成用露光
装置(光リソグラフィー装置)等に組み込まれるレン
ズ、プリズム、ウインドウ、リフレクター、フォトマス
ク、チューブ等に用いられている。従来、シリコンウエ
ハ上に集積電子回路パターンを描画する光リソグラフィ
ー装置の光源としてg線やi線などの水銀ランプによる紫
外線が用いられてきたが、半導体素子の微細化が高まる
に従い前記g線やi線では解像度に限界があり、より波長
の短いエキシマレーザが注目され、KrFエキシマレーザ
(248nm)を利用した光リソグラフィー装置が開発され
実施段階に入っている。
2. Description of the Related Art Silica glass optical materials as described above are:
For lenses, prisms, windows, reflectors, photomasks, tubes, etc. incorporated in excimer laser devices with wavelengths of 155 to 195 nm, irradiation devices for light cleaning using excimer lamps as light sources, exposure devices for integrated circuit production (optical lithography devices), etc. Used. Conventionally, ultraviolet light from a mercury lamp such as a g-line or an i-line has been used as a light source of an optical lithography apparatus that draws an integrated electronic circuit pattern on a silicon wafer. For lines, the resolution is limited, and an excimer laser with a shorter wavelength has attracted attention, and an optical lithography apparatus using a KrF excimer laser (248 nm) has been developed and is in the stage of implementation.

【0003】しかしながら、半導体素子の集積度は近い
将来さらに高まることが予測され、それには線幅0.1μm
以下の微細パターンを描画できる光源が必要とされる。
前記光源としてはArFエキシマレーザ(193nm)を主に、
ArClエキシマレーザ(175nm)、F2エキシマレーザ(157
nm)等の波長155〜195nmの高出力の真空紫外線が考えら
れ、その開発が始まっている。ところが、前記高出力真
空紫外線は従来の光リソグラフィー装置で使用する紫外
線よりさらに高出力であるところから、その照射を受け
た光学材料は透過率の低下、屈折率の上昇、歪みの発
生、蛍光の発生、場合によってはマイクロクラックの発
生等のダメージが急激に起こり光学材料として使用でき
なくなる。
However, it is expected that the degree of integration of semiconductor devices will further increase in the near future, with a line width of 0.1 μm.
A light source capable of drawing the following fine patterns is required.
The light source is mainly an ArF excimer laser (193 nm),
ArCl excimer laser (175 nm), F 2 excimer laser (157
nm) and other high-power vacuum ultraviolet rays with wavelengths of 155 to 195 nm have been considered, and their development has begun. However, since the high-output vacuum ultraviolet light has a higher output than the ultraviolet light used in the conventional photolithography apparatus, the irradiated optical material has a decrease in transmittance, an increase in refractive index, generation of distortion, and generation of fluorescence. In some cases, damage such as generation of microcracks occurs rapidly, and the optical material cannot be used.

【0004】また、現在、半導体素子の洗浄処理法とし
てArFエキシマレーザ(193nm)、F2エキシマレーザ(15
7nm)、Xe2エキシマランプ(172nm)、ArClエキシマラ
ンプ(175nm)等の波長155〜195nmの高出力真空紫外線
を用いたドライ洗浄法が開発されつつあるが、この洗浄
処理装置ではウインドウやチューブに大型の光学材料が
必要である。ところが、光学材料が大型化すると高出力
真空紫外線によるダメージは一段と大きくなり、光学材
料として使用できなくなる。こうした事情から、前記高
出力真空紫外線であるエキシマレーザまたはエキシマラ
ンプに対してダメージの少ない光学材料の開発が熱望さ
れていた。
At present, as a cleaning method for a semiconductor device, an ArF excimer laser (193 nm) and an F 2 excimer laser (15
7nm), Xe 2 excimer lamp (172nm), ArCl excimer lamp (175nm), etc., a dry cleaning method using high-power vacuum ultraviolet rays with a wavelength of 155 to 195nm is being developed. Large optical materials are required. However, when the size of the optical material is increased, the damage caused by the high-power vacuum ultraviolet rays is further increased, and the optical material cannot be used as an optical material. Under such circumstances, development of an optical material that causes less damage to an excimer laser or an excimer lamp, which is the high-output vacuum ultraviolet light, has been eagerly desired.

【0005】[0005]

【発明が解決しようとする課題】上記のような要望を満
足する光学材料としては、特開平6−227827号公
報に開示されたものが知られている。すなわち、上記公
報に開示された光学材料は、ガラス形成原料を火炎加水
分解させて得られる石英ガラス微粒子を基材に堆積・成
長させて形成された多孔質石英ガラス体を加熱して得ら
れる透明石英ガラスにおいて、該透明石英ガラス中のOH
含有量が10ppm以下であって、ハロゲンを400ppm以上含
有し、かつ水素を含有することを特徴とするものであ
る。
As an optical material that satisfies the above demands, there is known an optical material disclosed in Japanese Patent Application Laid-Open No. 6-227827. That is, the optical material disclosed in the above publication is a transparent quartz glass obtained by heating a porous quartz glass body formed by depositing and growing quartz glass fine particles obtained by flame hydrolysis of a glass forming raw material on a substrate. In quartz glass, OH in the transparent quartz glass
It has a content of 10 ppm or less, contains halogen of 400 ppm or more, and contains hydrogen.

【0006】また、上記要望に応える光学材料として本
発明者は、特公平6−48734号公報で水素ガス濃度
が少なくとも5×1016(molecules/cm)以上、OH基
濃度が100wtppm以上のレーザ光用光学部材を、また特公
平6−27013号公報で水素ガス濃度が少なくとも5
×1016(molecules/cm)以上、OH基濃度が50wtppm以
上、仮想温度に基づく屈折率変動分布でOH基の濃度分布
に基づく屈折率変動分布を打ち消し、実質的に屈折率変
動分布のない合成シリカガラス光学体を提案した。
As an optical material meeting the above demand, the present inventor has disclosed in Japanese Patent Publication No. 6-48734 a laser having a hydrogen gas concentration of at least 5 × 10 16 (molecules / cm 3 ) and an OH group concentration of 100 wt ppm or more. The optical member for light may be replaced with a gas having a hydrogen gas concentration of at least 5 in Japanese Patent Publication No. 6-27013.
× 10 16 (molecules / cm 3 ) or more, OH group concentration of 50 wtppm or more, refractive index fluctuation distribution based on fictive temperature cancels refractive index fluctuation distribution based on OH group concentration distribution, and has substantially no refractive index fluctuation distribution A synthetic silica glass optical body was proposed.

【0007】しかしながら、前記光学材料を例えば、直
径200mm×厚さ30mmを超える大型光学素子とすると、含
有する水素分子、OH基濃度及びハロゲンに不均一分布が
起こりやすく、エキシマレーザ、エキシマランプ照射下
において、透過率、屈折率が変化し光学特性の低下が起
こる。また、OH基濃度が100wtppm以上と高濃度でシリカ
ガラス光学材料に含まれると、真空紫外域で初期透過率
が低くなり、耐久性の低下が起こる。つまり、前記公報
で提案された光学材料は155〜195nm域の初期透過率が低
く、耐久性も不足していたという問題があった。また、
特開平6−227827号公報に開示された光学材料で
は、ハロゲン全般を用いているが、ハロゲンの中でもCl
等にあっては、紫外線照射により欠陥を生成しやすく、
目的とするスペクトル領域で透過率等、光学材料の性能
を劣化させるという大きな問題点を抱えていた。
However, when the optical material is a large optical element having a diameter of, for example, 200 mm × thickness of 30 mm, non-uniform distribution of hydrogen molecules, OH group concentration, and halogen is likely to occur. In, the transmittance and the refractive index change, and the optical characteristics deteriorate. Also, when the OH group concentration is as high as 100 wtppm or more in the silica glass optical material, the initial transmittance is reduced in the vacuum ultraviolet region, and the durability is reduced. That is, the optical materials proposed in the above publication have a problem that the initial transmittance in the 155 to 195 nm region is low and the durability is insufficient. Also,
In the optical material disclosed in JP-A-6-227827, halogen is used in general.
In such a case, it is easy to generate defects by ultraviolet irradiation,
There has been a major problem of deteriorating the performance of the optical material such as transmittance in a target spectral region.

【0008】そこで、本発明者等は鋭意研究を続けた結
果、光学材料に含まれる不純物濃度を上記公報記載の光
学材料よりさらに高純度とし(特にMoおよびWの濃度を
低濃度とし)、OH基濃度、水素分子濃度を特定の範囲と
し、かつそれらの濃度分布を均一にした上で、ハロゲン
の中からFを特に選択し、しかも該F濃度を上記従来技術
より少ない量の特定範囲量とすることで、透過率が高
く、屈折率変動幅Δnが小さく、エキシマレーザやエキ
シマランプの長時間照射に対する耐久性にも優れた合成
シリカガラス光学材料が得られることを見出した。ま
た、前記合成シリカガラス光学材料中のOH基濃度と水素
分子濃度を前記範囲よりさらに狭い範囲に限定すること
で特に波長155〜195nmのエキシマレーザに対しても初期
透過率が高く、耐久性も高く維持できることをも見出
し、本発明を完成したものである。
The inventors of the present invention have conducted intensive studies and have found that the concentration of impurities contained in the optical material is higher than that of the optical material described in the above-mentioned publication (particularly, the concentrations of Mo and W are lower), and the OH The base concentration and the hydrogen molecule concentration are in a specific range, and after making their concentration distribution uniform, F is particularly selected from the halogens, and the F concentration is smaller than that of the above-described conventional technology. By doing so, it has been found that a synthetic silica glass optical material having a high transmittance, a small refractive index variation width Δn, and excellent durability against long-time irradiation with an excimer laser or an excimer lamp can be obtained. Also, by limiting the OH group concentration and the hydrogen molecule concentration in the synthetic silica glass optical material to a range narrower than the above range, the initial transmittance is particularly high even for an excimer laser having a wavelength of 155 to 195 nm, and the durability is also high. They have also found that they can be kept high, and have completed the present invention.

【0009】すなわち、本発明は、波長155〜195nmのエ
キシマレーザ、エキシマランプに対して初期透過率が高
く、屈折率変動幅Δnが小さく、しかも長時間照射下で
の耐久性に優れたシリカガラス光学材料を提供すること
を目的とする。
That is, the present invention provides a silica glass having a high initial transmittance, a small refractive index fluctuation width Δn, and excellent durability under long-time irradiation with respect to excimer lasers and excimer lamps having wavelengths of 155 to 195 nm. An object is to provide an optical material.

【0010】[0010]

【課題を解決するための手段】上記課題は、本発明の下
記(1)〜(10)のいずれかに記載の構成により達成
される。 (1) 波長155〜195nmのエキシマレーザ及びエキシマ
ランプからの光線用シリカガラス光学材料であって、超
高純度であり、OH基を1〜100wtppm、H2を5×1016〜5
×1019分子/cm、及びFを10〜10,000wtppmを含有し、
F以外のハロゲンを実質的に含有せず、MoおよびWの含有
量が各0.1wtppb以下であり、かつ屈折率変動幅Δnが3
×10-6〜3×10-7であることを特徴とするシリカガラス
光学材料。 (2) OH基濃度変動幅ΔOHが30wtppm以内、かつF濃度
変動幅ΔFが50wtppm以内である上記(1)のシリカガラ
ス光学材料。 (3) H2濃度変動幅ΔH2が3×1017分子/cm3以内で
ある上記(1)または(2)のシリカガラス光学材料。 (4) OH基を12〜100wtppm、H2を3×1017〜1×1019
分子/cmを含有する上記(1)ないし(3)のいずれ
かのシリカガラス光学材料。 (5) Fを10〜380wtppmを含有する上記(1)ないし
(4)のいずれかのシリカガラス光学材料。 (6) 不純物として、Li、NaおよびKが各5wtppb以
下、CaおよびMgが各1wtppb以下、Cr、FeおよびNiが各
0.1wtppb以下含有する超高純度である上記(1)ないし
(5)のいずれかのシリカガラス光学材料。 (7) 7.6eV吸収帯を生成する酸素欠損型欠陥の濃度
が1×1017個/cm以下である上記(1)ないし(6)
のいずれかのシリカガラス光学材料。 (8) Cl含有量が10wtppm以下である上記(1)ない
し(7)のいずれかのシリカガラス光学材料。 (9) エキシマレーザまたはエキシマランプからの光
線の光路長が30mm以上である光学素子に用いる上記
(1)ないし(8)のいずれかのシリカガラス光学材
料。 (10) OH基を1〜100wtppm、H2を5×1016〜5×10
19分子/cm、及びFを50〜10,000wtppm含有し、そして
OH基量をa、F量をbとしたとき、aとbの合計量が
100wtppm以上であり、かつb/aが1〜1000を満足する
上記(1)ないし(9)のいずれかのシリカガラス光学
材料。
Means for Solving the Problems The above object is achieved by the present invention according to any one of the following (1) to (10). (1) A silica glass optical material for light from an excimer laser and an excimer lamp with a wavelength 155~195Nm, an ultra high purity, 1~100Wtppm an OH group, a H 2 5 × 10 16 ~5
× 10 19 molecules / cm 3 , and F containing 10 to 10,000 wtppm,
It contains substantially no halogen other than F, the content of Mo and W is 0.1 wtppb or less, and the refractive index variation Δn is 3
A silica glass optical material characterized by having a size of × 10 −6 to 3 × 10 −7 . (2) The silica glass optical material according to (1), wherein the OH group concentration variation ΔOH is within 30 wtppm and the F concentration variation ΔF is within 50 wtppm. (3) The silica glass optical material according to the above (1) or (2), wherein the H 2 concentration fluctuation width ΔH 2 is within 3 × 10 17 molecules / cm 3. (4) 12 to 100 ppm by weight of OH group and 3 × 10 17 to 1 × 10 19 of H 2
The silica glass optical material according to any one of the above (1) to (3), which contains molecules / cm 3 . (5) The silica glass optical material according to any one of the above (1) to (4), containing 10 to 380 wtppm of F. (6) As impurities, Li, Na and K are each 5 wtppb or less, Ca and Mg are each 1 wtppb or less, Cr, Fe and Ni are each.
The silica glass optical material according to any one of the above (1) to (5), which has an ultra-high purity of 0.1 wtppb or less. (7) The above (1) to (6), wherein the concentration of oxygen-deficient defects producing a 7.6 eV absorption band is 1 × 10 17 defects / cm 3 or less.
The silica glass optical material according to any of the above. (8) The silica glass optical material according to any one of (1) to (7), wherein the Cl content is 10 wtppm or less. (9) The silica glass optical material according to any one of (1) to (8), which is used for an optical element having an optical path length of a light beam from an excimer laser or an excimer lamp of 30 mm or more. (10) an OH group 1~100Wtppm, the H 2 5 × 10 16 ~5 × 10
When 19 molecules / cm 3 and 50 to 10,000 wt ppm of F are contained, and the amount of OH groups is a and the amount of F is b, the total amount of a and b is
The silica glass optical material according to any one of the above (1) to (9), wherein the silica glass optical material is at least 100 wtppm and b / a satisfies 1 to 1000.

【0011】[0011]

【発明の実施の形態】本発明は、超高純度、OH基含有、
フッ素F含有、溶存水素ガス、MoおよびW濃度、屈折率変
動幅Δnの6つの物性組合せにより、さらなる初期透過
率、耐エキシマレーザ性、耐エキシマランプ性の向上お
よびエキシマレーザ及びエキシマランプを用いての加工
精度の向上を達成した。
BEST MODE FOR CARRYING OUT THE INVENTION The present invention provides ultra-high purity,
Further improvement of initial transmittance, excimer laser resistance, excimer lamp resistance, and use of excimer laser and excimer lamp by combining six physical properties of fluorine F content, dissolved hydrogen gas, Mo and W concentrations, and refractive index fluctuation width Δn The improvement of the processing accuracy was achieved.

【0012】6つの物性組合せが必要である理由として
以下のとおりである。上記超高純度とは、上記公報記載
の光学材料より更に純度が高く、不純物金属含有濃度が
下記の範囲であるものをいい、シリカガラス中の不純物
金属濃度を少なくすることにより真空紫外域での透過率
の向上と紫外線照射時のエネルギー吸収を少なくでき
る。Li、Na、Kは各々5wtppb以下、Ca、Mgは各々1wtpp
b以下、Cr、FeおよびNiは、各々0.1wtppb以下、Moおよ
びWは各々0.1wtppb以下であること。Li、Na、K、Ca、Mg
は各種耐熱性セラミックスの不純物として含有されてお
り、シリカガラス製造時に汚染元素となりやすく、Cr、
Fe、Ni、Mo、Wはプラントの構造材の組成物、特にMoとW
は耐熱性金属元素として使用されており、やはり汚染元
素となりやすい。
The reason why the combination of the six physical properties is necessary is as follows. The ultra-high purity refers to a material whose purity is higher than the optical material described in the above publication and whose impurity metal content is in the following range, and in the vacuum ultraviolet region by reducing the impurity metal concentration in silica glass. It is possible to improve transmittance and reduce energy absorption at the time of ultraviolet irradiation. Li, Na, and K are each 5 wtppb or less, and Ca and Mg are each 1 wtpp.
b or less, Cr, Fe and Ni are each 0.1 wtppb or less, and Mo and W are each 0.1 wtppb or less. Li, Na, K, Ca, Mg
Is contained as an impurity in various heat-resistant ceramics, and easily becomes a contaminant element when producing silica glass.
Fe, Ni, Mo, W are compositions of plant structural materials, especially Mo and W
Is used as a heat-resistant metal element and tends to be a contaminant element.

【0013】OH基は、ガラス網目構造の終端部であり適
量含有することにより構造をリラックスさせ、Si-O-Si
の結合角度を安定値に近づける。しかしながらOH基が高
濃度に含有されると真空紫外域での透過率低下の原因と
なる。したがって、OH基含有量は1〜100wtppm、特に単
位面積当たりの照射エネルギー密度が高く条件の厳しい
155〜195nmのエキシマレーザ用では12〜100wtppmが良
い。
The OH group is a terminal portion of the glass network structure, and the structure is relaxed by containing an appropriate amount thereof, and the Si—O—Si
To a stable value. However, when the OH group is contained at a high concentration, it causes a decrease in transmittance in a vacuum ultraviolet region. Therefore, the OH group content is 1 to 100 wtppm, especially the irradiation energy density per unit area is high and the conditions are severe.
For excimer lasers of 155 to 195 nm, 12 to 100 wtppm is good.

【0014】Fは、OH基と同様にガラス網目構造終端部
となる。またFは、他のハロゲンと異なり高濃度で含有
させても真空紫外域での透過率低下の原因とならない。
しかしOH基を全く含ませずFのみ高濃度で含有するガラ
スは加熱処理により分解し、F2ガス発生や酸素欠損型生
成による7.6eV(約165nm)吸収帯を生ずる。したがっ
て、OH基とFを同時に含有させガラスの熱分解と酸素欠
損型欠陥の生成を抑制することが重要となる。この観点
からは、OH基量をa、F量をbとしたとき、aとbの合計量
が100wtppm以上であり、かつb/aが1〜1000を満足する
ことが好ましい。上記b/aの値は特に10〜100が好まし
い。この場合、OH基を1〜100wtppm、特に12〜100wtpp
m、Fを50〜10,000wtppm、特に50〜380wtppm含有してい
ることが好ましい。なお、本発明の光学材料において
は、F以外のハロゲンを実質的に含有せず、特に、Clに
あっては、エキシマレーザやエキシマランプの照射によ
ってガラスの真空紫外域(エキシマレーザの波長域)で
の透過率の低下を生じさせるので、その含有量が10wtpp
m以下であることが好ましい。
F is the terminal of the glass network structure similarly to the OH group. Further, unlike other halogens, even if F is contained at a high concentration, it does not cause a decrease in transmittance in a vacuum ultraviolet region.
However, glass containing no OH group and containing only F at a high concentration is decomposed by heat treatment, and generates a 7.6 eV (about 165 nm) absorption band due to generation of F 2 gas and generation of oxygen deficiency type. Therefore, it is important to simultaneously contain OH groups and F to suppress the thermal decomposition of glass and the generation of oxygen-deficient defects. From this viewpoint, when the amount of OH groups is a and the amount of F is b, the total amount of a and b is preferably 100 wtppm or more, and b / a preferably satisfies 1 to 1000. The value of b / a is particularly preferably from 10 to 100. In this case, the OH group is 1 to 100 wtppm, especially 12 to 100 wtpp.
It is preferable that m and F are contained at 50 to 10,000 wtppm, particularly 50 to 380 wtppm. The optical material of the present invention does not substantially contain any halogen other than F. In particular, Cl is irradiated with an excimer laser or an excimer lamp to irradiate a glass with a vacuum ultraviolet region (wavelength region of an excimer laser). Content of 10 wtpp
m or less.

【0015】溶存水素ガスすなわち光学材料内の水素分
子H2は、紫外線照射によるE'センター(イープライムセ
ンターと呼び約215nm吸収帯を示す)やNBOHセンター
(ノンブリッジング、オキシジェン、ホールセンターと
呼び約260nm及び約630nm吸収帯を示すとされている)の
生成を抑制する作用(S.Yamagata,Mineralogical Journ
al,Vol15,No.8,1991,pp.333-342に示す)があり、その
含有量は、5×1016〜5×1019分子/cm、特に3×10
17〜1×1019分子/cmであることが好ましい。
Dissolved hydrogen gas, that is, hydrogen molecule H2 in the optical material, is irradiated with ultraviolet rays at the E 'center (called an e-prime center and showing an absorption band of about 215 nm) or the NBOH center (called a non-bridging, oxygen, or hole center). Action to suppress the generation of absorption bands at 260 nm and about 630 nm (S. Yamagata, Mineralogical Journal)
al, Vol 15, No. 8, 1991, pp. 333-342), and its content is 5 × 10 16 to 5 × 10 19 molecules / cm 3 , especially 3 × 10
It is preferably 17 to 1 × 10 19 molecules / cm 3 .

【0016】光学材料が、上記特開平6−227827
号公報に開示された光学材料のようにフォトマスクのよ
うな厚さ(レーザが通過する光路長)たかだか2〜3mm
程度の製品に用いられる場合には問題にならないが、厚
さが30mm以上の製品すなわちレンズのような光学素子で
は、屈折率変動幅Δnが大きいと、それを用いての加工
精度が低下するため、上記Δnはできるだけ小さい方が
よい。しかし、特に上記したように、Fを高濃度でドー
プさせると、濃度分布によりΔnが増大してしまうとい
う問題が新たに知見された。そこで、本発明の光学材料
においては、後述する製造方法で説明する処理を行うこ
とによって、屈折率変動幅Δnを3×10-6〜3×10-7
いう小さな値に設定した。このように、Δnの値が小さ
いということは、材料の密度変動も小さいことを意味
し、その結果、水素ガスを均一濃度で溶存させることが
可能となる。Δnが3×10-6以下ということは、前提と
して少なくとも1方向脈理フリーであることが必要とな
る。Δn値が大きなガラスではOH基やFの濃度分布が不均
一であり、飽和水素ガス濃度はこれらOH基やFの濃度に
影響されているものと推定している。以上から、本発明
の光学材料では、OH基濃度変動幅ΔOHが30wtppm以内、
かつF濃度変動幅ΔFが50wtppm以内であることが好まし
く、また、H2濃度変動幅ΔH2が3×1017分子/cm以下
であることが好ましい。また、7.6eV吸収帯を生成する
酸素欠損型欠陥の濃度は、1×1017個/cm以下である
ことが好ましい。
The optical material is the same as that of the above-mentioned JP-A-6-227827.
Thickness (optical path length through which laser passes) like a photomask like the optical material disclosed in Japanese Patent Publication No.
This is not a problem when used for products of the order of magnitude, but for products with a thickness of 30 mm or more, that is, optical elements such as lenses, if the refractive index fluctuation width Δn is large, the processing accuracy using it will decrease. , .DELTA.n should be as small as possible. However, as described above, it has been newly found that, when F is doped at a high concentration, Δn increases due to the concentration distribution. Therefore, in the optical material of the present invention, the refractive index fluctuation width Δn is set to a small value of 3 × 10 −6 to 3 × 10 −7 by performing a process described in a manufacturing method described later. As described above, a small value of Δn means that a change in the density of the material is small, and as a result, the hydrogen gas can be dissolved at a uniform concentration. When Δn is 3 × 10 −6 or less, it is necessary that at least one direction be stria-free. It is presumed that the concentration distribution of OH groups and F is not uniform in glass having a large Δn value, and the saturated hydrogen gas concentration is affected by the concentrations of these OH groups and F. From the above, in the optical material of the present invention, the OH group concentration fluctuation width ΔOH is within 30 wtppm,
Further, the F concentration fluctuation width ΔF is preferably within 50 wtppm, and the H 2 concentration fluctuation width ΔH 2 is preferably 3 × 10 17 molecules / cm 3 or less. Further, the concentration of oxygen-deficient defects generating the 7.6 eV absorption band is preferably 1 × 10 17 defects / cm 3 or less.

【0017】次に、以上説明した本発明のシリカガラス
光学材料の製造方法について説明する。本発明のシリカ
ガラス光学材料を製造するには、まず珪素化合物を原料
とする火炎加水分解法によるOH基含有白色スート体を合
成する。上記珪素化合物としては、上記珪素化合物とし
ては、SiCl4、SiHCl3、SiH2Cl2、SiCH3Cl3、Si(CH3)2Cl
2、SiF4、SiHF3、SiH2F2 等を用いることができる。火
炎としては、酸水素火炎、プロパン酸素火炎等を用いる
ことができる。ついで、得られたOH基含有白色スート体
をフッ素含有ガス雰囲気熱処理によりフッ素ドープ処理
する。フッ素含有ガスとしては、SiF4、CHF3、SF6等を
0.1〜100 vol.%含有するガスを用いることが好まし
い。処理温度は400〜1200℃、圧力は0.1〜10 kgf/cm2
とすることが好ましい。この後、上記白色スート体の透
明ガラス化処理を行う。この処理は、0.1 kgf/cm2以下
の減圧雰囲気(Heを含有しても良い)下で、温度1400〜
1600℃で行うことが好ましい。続いて、火炎加熱による
棒状透明シリカガラス体への成型及び帯溶融回転攪拌処
理を行う。これらの処理は、USP2904713、USP3128166、
USP3128169、USP3483613等に示された方法を用いて行う
ことができる。とくに、上記したように、屈折率変動幅
Δnが3×10-6〜3×10-7となるように十分に行う。この
後、歪除去のためのアニール処理を行う。この処理の雰
囲気としては、一般的には大気が用いられており、その
他不活性ガス雰囲気も用いることができる。処理温度
は、900〜1200℃で、1〜100時間程度保持し、その後500
℃以下まで1℃/hr〜10℃/hrにて徐冷却する。最後
に、水素分子含有雰囲気熱処理による水素ガスドープ処
理を行う。水素分子含有雰囲としては、水素ガス100%
又はAr等の希ガスと水素ガスとの混合ガス雰囲気を用い
ることが好ましい。処理温度は100〜800℃、特に200〜4
00℃であることが好ましい。上記温度範囲より高温であ
ると還元作用が強くなり、酸素欠損型欠陥を生成させ、
低温であると水素ガスの透明ガラス体への拡散溶存への
時間がかかりすぎる。処理圧力は、大気圧の約1 kgf/c
m2から100 kgf/cm2が好ましい。水素ガス100%で1 kgf
/cm2での透明ガラス体の水素ガス飽和溶存濃度は約1×
1017 〜 4×10 17分子/cm3、10 kgf/cm2、100 kgf/cm
2では各々 1×1018 〜 4×1018、1×10 19 〜 4×1019
子/cm3である。なお、得られた材料は、外表面を研削
し所望の形状とされる。
Next, the silica glass of the present invention described above
A method for manufacturing an optical material will be described. The silica of the present invention
The first step in manufacturing glass optical materials is to use silicon compounds as raw materials.
OH group-containing white soot by flame hydrolysis
To achieve. As the silicon compound, the silicon compound is used.
The SiClFour, SiHClThree, SiHTwoClTwo, SiCHThreeClThree, Si (CHThree)TwoCl
Two, SiFFour, SiHFThree, SiHTwoFTwoEtc. can be used. fire
As the flame, use oxyhydrogen flame, propane oxygen flame, etc.
be able to. Next, the obtained OH group-containing white soot body was obtained.
Dope by heat treatment with fluorine-containing gas atmosphere
I do. As a fluorine-containing gas, SiFFour, CHFThree,SCIENCE FICTION6Etc.
It is preferable to use a gas containing 0.1 to 100 vol.%.
No. Processing temperature is 400 ~ 1200 ℃, pressure is 0.1 ~ 10 kgf / cmTwo
It is preferable that Thereafter, the white soot body is transparent.
A vitrification treatment is performed. This treatment is 0.1 kgf / cmTwoLess than
Under reduced pressure atmosphere (which may contain He)
It is preferably performed at 1600 ° C. Then, by flame heating
Molding into a rod-shaped transparent silica glass body and band melting rotation stirring
Work. These processes are based on USP2904713, USP3128166,
Perform using the method shown in USP3128169, USP3483613, etc.
be able to. In particular, as described above, the refractive index fluctuation width
Δn is 3 × 10-6~ 3 × 10-7Perform enough to be. this
After that, an annealing process for removing distortion is performed. The atmosphere of this process
As the atmosphere, the atmosphere is generally used.
Other inert gas atmospheres can also be used. Processing temperature
Is maintained at 900-1200 ° C for about 1-100 hours, then 500
Cool slowly at 1 ° C / hr to 10 ° C / hr below ℃. last
In addition, hydrogen gas doping treatment by heat treatment in an atmosphere containing hydrogen molecules
Work. As atmosphere containing hydrogen molecules, 100% hydrogen gas
Or use a mixed gas atmosphere of a rare gas such as Ar and hydrogen gas
Preferably. Processing temperature is 100 ~ 800 ℃, especially 200 ~ 4
Preferably it is 00 ° C. Higher than the above temperature range
When this occurs, the reducing action becomes stronger, generating oxygen-deficient defects,
At low temperatures, diffusion of hydrogen gas into transparent glass
It takes too long. Processing pressure is about 1 kgf / c of atmospheric pressure
mTwoFrom 100 kgf / cmTwoIs preferred. 1 kgf with 100% hydrogen gas
/cmTwoHydrogen gas saturation dissolved concentration of the transparent glass body at about 1 ×
Ten17~ 4 × 10 17Molecule / cmThree, 10 kgf / cmTwo, 100 kgf / cm
TwoThen 1 × 10 each18 ~ 4 × 1018, 1 × 10 19 ~ 4 × 1019Minute
Child / cmThreeIt is. The obtained material has its outer surface ground.
And a desired shape.

【0018】[0018]

【実施例】まず、四塩化珪素SiCl4を原料とし、酸水素
炎加水分解法により、OH基含有白色スート体を合成し
た。ついで、得られたOH基含有白色スート体を、SiF4 5
0%含有ガス雰囲気で、1 kg/cm2(ほぼ大気圧と同
じ)、700〜1200℃の範囲の条件下での加熱処理による
フッ素ドープ処理を行った。このとき、熱処理温度を処
理時間を種々変えて、表1および2に示したように各実
施例および各比較例のシリカガラス光学材料のOH基およ
びF量を変化させた。続いて、各白色スート体を、0.00
1 kgf/cm2以下の真空(減圧)雰囲気下で、温度1400〜
1600℃で加熱して透明ガラス化した。この後、プロパン
ガス火炎加熱により、材料を軟化させて、断面形状がほ
ぼ円形の棒状材料とした。この棒状材料の長さは約2m
であり、直径は約60mmとした。この棒状材料の両端を
保持し、プロパンガス火炎加熱に局所的に加熱しながら
捻り、帯溶融回転攪拌処理を行った。加熱は、材料が20
00℃程度になるように行った。この帯溶融回転攪拌処理
により、各材料を1方向脈理フリーの透明ガラス体とし
た。なお、比較例3は、この帯溶融回転攪拌処理を行わ
なかったこと以外は、組成等が実施例3の材料と同一の
ものである。この後、透明ガラス体を寸法、直径300m
m、厚さ約70mmに加熱成型し、次いで電気炉内に設置
し、大気雰囲気下、1150℃、20時間保持後、4℃/hrに
て800℃まで徐冷し、その後、電気炉電源を切り自然冷
却してアニール処理を行った。次に、透明ガラス体をス
テンレススチールジャケット、タングステンメッシュヒ
ータの電気炉内に設置し、水素100%雰囲気下、400℃加
圧下にて水素ガスドープを行った。このとき、圧力を1
kgf/cm2または10 kgf/cm2と変化させて、各材料の溶
存水素量を表に示したように変化させた。最後に、透明
ガラス体の外表面を研削し、実施例および比較例の直径
250mm、厚さ50mmの円柱体のサンプルを得た。比較例1で
は、実施例1と同一の条件にてOH基含有白色スート体を
合成した後、SiF4100%ガス雰囲気、1 kgf/cm2、1100
℃の条件にて加熱処理を行いFドープOH基フリーとした
以外は実施例1や2と同一の条件で回転撹拌処理、水素
ドープ処理を行ってサンプルを得た。
EXAMPLES First, an OH group-containing white soot was synthesized from silicon tetrachloride SiCl 4 by a oxyhydrogen flame hydrolysis method. Then, the obtained OH group-containing white soot was subjected to SiF 4 5
In a gas atmosphere containing 0%, fluorine doping treatment was performed by heat treatment under the conditions of 1 kg / cm 2 (almost the same as atmospheric pressure) and 700 to 1200 ° C. At this time, the OH group and the F content of the silica glass optical material of each example and each comparative example were changed as shown in Tables 1 and 2 by variously changing the heat treatment temperature and the treatment time. Then, add each white soot body to 0.00
Under a vacuum (reduced pressure) atmosphere of 1 kgf / cm 2 or less,
The mixture was heated at 1600 ° C. to form a transparent glass. Thereafter, the material was softened by propane gas flame heating to obtain a rod-shaped material having a substantially circular cross section. The length of this rod material is about 2m
And the diameter was about 60 mm. The rod-shaped material was held at both ends, twisted while locally heating to propane gas flame heating, and a band melting rotary stirring process was performed. Heat the material to 20
It was performed so as to be about 00 ° C. By this band melting rotation stirring process, each material was made into a unidirectional stria-free transparent glass body. Comparative Example 3 has the same composition and the like as the material of Example 3 except that the zone melting rotation stirring process was not performed. After this, the size of the transparent glass body is 300 m in diameter.
m, heat molded to a thickness of about 70 mm, then placed in an electric furnace, kept at 1150 ° C for 20 hours under air atmosphere, gradually cooled to 800 ° C at 4 ° C / hr, and then turned on the electric furnace power. The cut was naturally cooled and an annealing treatment was performed. Next, the transparent glass body was placed in an electric furnace with a stainless steel jacket and a tungsten mesh heater, and hydrogen gas doping was performed under an atmosphere of 100% hydrogen under a pressure of 400 ° C. At this time, the pressure is 1
By changing to kgf / cm 2 or 10 kgf / cm 2 , the dissolved hydrogen amount of each material was changed as shown in the table. Finally, the outer surface of the transparent glass body was ground,
A cylindrical sample having a thickness of 250 mm and a thickness of 50 mm was obtained. In Comparative Example 1, an OH group-containing white soot body was synthesized under the same conditions as in Example 1, and then SiF 4 100% gas atmosphere, 1 kgf / cm 2 , 1100
A sample was obtained by performing a rotary stirring process and a hydrogen doping process under the same conditions as in Examples 1 and 2 except that a heat treatment was performed at a temperature of ° C. to make the F-doped OH group free.

【0019】比較例2では、水素ガスドープ処理を行わ
なかったこと以外は実施例3や4と同様にしてサンプル
を得た。得られたガラスは、水素ガスを溶存していない
ガラスであった。
In Comparative Example 2, a sample was obtained in the same manner as in Examples 3 and 4, except that the hydrogen gas doping treatment was not performed. The obtained glass was a glass in which hydrogen gas was not dissolved.

【0020】比較例3では、上記したように回転撹拌処
理を行わなかったこと以外は、比較例2と同様条件でサ
ンプルを得た。
In Comparative Example 3, a sample was obtained under the same conditions as in Comparative Example 2, except that the rotary stirring treatment was not performed as described above.

【0021】比較例4では、Fドープ処理を行わず、そ
の代りにCl2 100%ガス雰囲気にてClドープを行った以
外は実施例2と同様にしてサンプルを得た。得られたガ
ラスはClを900 wtppm含んでいた。
In Comparative Example 4, a sample was obtained in the same manner as in Example 2 except that F doping was not performed, and instead, Cl doping was performed in a Cl 2 100% gas atmosphere. The obtained glass contained 900 wtppm of Cl.

【0022】比較例5では、単にFドープ処理を行わな
っかたこと以外は実施例と同様にしてサンプルを得た。
得られたガラスはOH基を300 wtppm含んでいた。上記実
施例および比較例のサンプルにつき、上記のOH基濃度の
他、OH基濃度変動幅ΔOH、F濃度及びF濃度変動幅Δ
F、Cl濃度、溶存水素濃度及び溶存水素濃度変動幅Δ
H2、酸素欠損型欠陥濃度、屈折率変動幅Δn、歪量、
レーザおよびランプからの光線照射前後の透過率、並び
にレーザ及びランプ照射後の均質性、すなわちΔn値と
歪量を測定した。その結果を各表に示した。また、実施
例1,2,4,5及び比較例3のサンプルのガラスの不
純物含有量を表5に示した。上記実施例及び比較例の各
物性値等の測定法は下記の方法による。
In Comparative Example 5, a sample was obtained in the same manner as in Example except that the F doping treatment was not performed.
The obtained glass contained 300 wtppm of OH groups. For the samples of the above Examples and Comparative Examples, in addition to the above OH group concentration, the OH group concentration fluctuation width ΔOH, the F concentration and the F concentration fluctuation width Δ
F, Cl concentration, dissolved hydrogen concentration and fluctuation range of dissolved hydrogen concentration Δ
H2 , oxygen deficiency type defect concentration, refractive index fluctuation width Δn, strain amount,
The transmittance before and after the irradiation of the light from the laser and the lamp, and the homogeneity after the irradiation of the laser and the lamp, that is, the Δn value and the amount of strain, were measured. The results are shown in each table. Table 5 shows the impurity contents of the glasses of the samples of Examples 1, 2, 4, 5 and Comparative Example 3. The methods for measuring the physical properties and the like in the above Examples and Comparative Examples are as follows.

【0023】(i) OH基濃度の測定法 D.M. DODD and D.B. FRASE R, Optical determination
of OH in fused silica, Journal of Applied Physic
s, Vol. 37(1966)P.3911文献記載の測定法。 (ii) OH基濃度変動幅及び平均値の測定法 直径250mm、厚さ50mmの円柱状シリカガラス光学材料に
おいて、回転対称軸方向からみて直径方向に10mm間隔に
て25点のOH基濃度測定を行う。25点のOH基濃度の最大値
と最小値から光学材料全体におけるOH基濃度変動幅(Δ
OH)を、25点のOH基濃度の算術平均値からOH基平均濃度
を計算する測定法。 (iii) 水素分子濃度の測定法。 V.K. KHOTIMCHENKO,et al., Determining the conten
t of hydrogen dissolved in quartz glass using the
methods of Raman scattering and mass spectrometry,
Journal of Applied Spectroscopy, Vo.46, No.6(198
7) pp632〜635の文献記載の測定法。 (iv) 水素分子濃度変動幅及び平均値の測定法。 直径250mm、厚さ50mmの円柱状シリカガラス光学材料に
おいて、回転対称軸方向からみて直径方向に10mm間隔に
て25点のH2濃度測定を行う。25点のH2濃度の最大値と最
小値から光学材料全体におけるH2濃度変動幅(ΔH2
を、25点のH2濃度の算術平均値からH2平均濃度を計算す
る測定法。 (v) 塩素濃度の測定法。 HF水溶液により分解後、AgNO3添加による比濁法による
測定法。 (vi) フッ素濃度の測定法。 NaOH水溶液にて分解後、イオン電極法により測定する。 (vii) フッ素濃度変動幅及び平均値の測定法。 直径250mm、厚さ50mmの円柱状シリカガラス光学材料に
おいて、回転対称軸方向からみて直径方向に10mm間隔に
て25点のF濃度測定を行う。25点のF濃度の最大値と最小
値から光学材料全体におけるフッ素濃度変動幅(ΔF)
を、25点のF濃度の算術平均値から濃度平均値を計算す
る方法。 (viii) シリカガラス中の不純物測定 Na、K、Mg、Ca、Feは原子吸光光度法による測定法、L
i、Cr、Ni、Mo、Wはプラズマ質量分析法により測定(IC
P-MS法)。 (ix) 屈折率変動幅(Δn)の測定法 He-Neレーザ(633nm)を光源とする光干渉法による測定
法。ただし、直径230mmエリアにおける値を示す。 (x) 複屈折量(歪量)の測定法。 偏光板歪計を用いたレターデーション測定法。ただし、
直径230mmエリアにおける値を示す。 (xi) ArFエキシマレーザ照射後の193nmの透過率の測定
法。 サイズ30×20×厚さ10 mm、両面鏡面研磨仕上したサン
プルに波長193nm、波長半長値幅3nm、パルス寿命半値幅
17 nsec、エネルギー密度30 mJ/cm2 /shot、周波数200
Hzで照射ショット数1×106 shotのレーザ照射した直後
3分後の193nmでの透過率を測定する測定法。 (xii) Xe2エキシマランプ照射後の波長172nmの透過率の
測定法。 サイズ30×20×厚さ10 mm、両面鏡面研磨仕上したサン
プルに波長172nm、波長半値幅14nm、ランプエネルギー
密度10 mW/cm2で14日間照射した直後3分後の172nmでの
透過率を測定する測定法。 (xiii) 酸素欠損型欠陥濃度の測定法。 H.Hosono, et al., Experimental evidence for the S
i-Si bond model of the 7.6 eV band in SiO2 glass,
Physical Review B, Vol. 44, No.21, (1991)pp. 12043
-12045の文献記載の測定法。
(I) Method for measuring OH group concentration: D.M. DODD and D.B. FRASE R, Optical determination
 of OH in fused silica, Journal of Applied Physic
s, Vol. 37 (1966) P.3911. (ii) Measurement method of OH group concentration fluctuation width and average value
At 10mm intervals in the diameter direction when viewed from the rotational symmetry axis direction.
OH group concentration measurement at 25 points. Maximum value of OH group concentration at 25 points
And the minimum value, the OH group concentration fluctuation width (Δ
OH) is calculated from the arithmetic mean of the OH group concentrations at 25 points.
Measurement method to calculate. (iii) A method for measuring the concentration of hydrogen molecules. V.K. KHOTIMCHENKO, et al., Determining the conten
t of hydrogen dissolved in quartz glass using the
methods of Raman scattering and mass spectrometry,
 Journal of Applied Spectroscopy, Vo.46, No.6 (198
7) Measurement method described in the literature of pp632-635. (iv) A method for measuring the fluctuation range and average value of the hydrogen molecule concentration. For cylindrical silica glass optical materials with a diameter of 250 mm and a thickness of 50 mm
At 10mm intervals in the diameter direction when viewed from the rotational symmetry axis direction.
H of 25 pointsTwoPerform a concentration measurement. 25 points of HTwoMaximum and maximum density
From small values to H in the entire optical materialTwoConcentration fluctuation range (ΔHTwo)
And 25 points of HTwoH from the arithmetic mean of the concentrationTwoCalculate average concentration
Measurement method. (v) Method for measuring chlorine concentration. AgNO after decomposition with HF aqueous solutionThreeBy turbidimetry by addition
Measurement method. (vi) Method for measuring fluorine concentration. After decomposition with an aqueous NaOH solution, measurement is performed by the ion electrode method. (vii) A method for measuring the fluctuation range and average value of fluorine concentration. For cylindrical silica glass optical materials with a diameter of 250 mm and a thickness of 50 mm
At 10mm intervals in the diameter direction when viewed from the rotational symmetry axis direction.
And measure the F concentration at 25 points. 25 points maximum and minimum F density
From the value, the fluorine concentration fluctuation width (ΔF) in the entire optical material
Is calculated from the arithmetic mean of the 25 F concentrations.
Way. (viii) Impurity measurement in silica glass Na, K, Mg, Ca, Fe are measured by atomic absorption spectrometry, L
i, Cr, Ni, Mo, W are measured by plasma mass spectrometry (IC
P-MS method). (ix) Measurement method of refractive index fluctuation width (Δn) Measurement by optical interferometry using He-Ne laser (633nm) as light source
Law. However, the values in the area of 230 mm in diameter are shown. (x) Birefringence (strain) measurement method. A retardation measurement method using a polarizing plate strain meter. However,
The values in the area of 230 mm in diameter are shown. (xi) Measurement of 193 nm transmittance after ArF excimer laser irradiation
Law. Size 30 x 20 x 10 mm thick, sun mirror-polished on both sides
193nm wavelength, half-width 3nm, half-width pulse life
17 nsec, energy density 30 mJ / cmTwo / Shot, frequency 200
 1 × 10 irradiation shots at Hz6 Immediately after shot laser irradiation
A measuring method for measuring the transmittance at 193 nm after 3 minutes. (xii) XeTwo172nm wavelength transmittance after excimer lamp irradiation
Measurement method. Size 30 x 20 x 10 mm thick, sun mirror-polished on both sides
172nm wavelength, 14nm half width, lamp energy
Density 10 mW / cmTwoAt 172nm 3 minutes after irradiation for 14 days
A measuring method for measuring transmittance. (xiii) A method for measuring the concentration of oxygen-deficient defects. H. Hosono, et al., Experimental evidence for the S
i-Si bond model of the 7.6 eV band in SiOTwo glass,
Physical Review B, Vol. 44, No. 21, (1991) pp. 12043
Measurement method described in -12045.

【表1】[実施例] [Table 1] [Example]

【表2】[実施例] [Table 2] [Example]

【表3】[比較例] [Table 3] [Comparative example]

【表4】[比較例] [Table 4] [Comparative example]

【表5】[不純物分析値] 表から明らかなように、実施例2、3、4は特に耐ArFエキシ
マレーザ性に優れており、また、これらの実施例2、3、
4は特に耐Xe2エキシマランプ性にも優れていた。また実
施例1〜6のガラスはエキシマ光照射後もΔn値は3×10
-6以下、歪量も1nm/cm以下と高均質性を示した。
[Table 5] [Impurity analysis value] As is clear from the table, Examples 2, 3, and 4 are particularly excellent in ArF excimer laser resistance, and these Examples 2, 3, and
No. 4 was also particularly excellent in Xe 2 excimer lamp resistance. Further, the glasses of Examples 1 to 6 had a Δn value of 3 × 10 even after excimer light irradiation.
-6 or less, and the strain amount was 1 nm / cm or less, indicating high homogeneity.

【0024】一方、比較例1では、OH基を含有せず、Fを
1600 wtppm含有するガラスであったため、各種加熱処理
によりガラスが分解してFガスを発生し、7.6eV吸収帯
を示す酸素欠損型欠陥を生成し、耐エキシマ光性が不良
であった。
On the other hand, in Comparative Example 1, no OH group was contained and F was
Since the glass contained 1600 wtppm, the glass was decomposed by various heat treatments to generate F 2 gas, to generate oxygen-deficient defects having a 7.6 eV absorption band, and the excimer light resistance was poor.

【0025】比較例2では、水素ガスを溶存していない
ガラスであるため、耐エキシマ光性が悪かった。
In Comparative Example 2, excimer light resistance was poor because the glass did not dissolve hydrogen gas.

【0026】比較例3では、帯溶融回転攪拌処理を行わ
なかったため、ΔOH、ΔF、ΔH2の値が他と比較して大
きくなっており、Δnの値も大きい数値である。また耐
エキシマ光性もガラスの部位によって変化が大きかっ
た。
[0026] In Comparative Example 3, because you did not zone melting rotary stirring treatment, DerutaOH, [Delta] F, the value of [Delta] H 2 has become larger than the other, the value of Δn is also large numbers. Also, the excimer light resistance varied greatly depending on the part of the glass.

【0027】比較例4では、Clを900 wtppm含みFフリ
ーのものであるため、エキシマ光照射によって光の透過
率が激減してしまった。
In Comparative Example 4, the light transmittance was sharply reduced by excimer light irradiation because it was F-free containing 900 wtppm of Cl.

【0028】比較例5では、FもClも含有せず、OH基
を300 wtppmという過剰に含むものであるため、紫外線
吸収端が長波長側へシフトしており、耐エキシマ光性も
不良であった。
Comparative Example 5 contained neither F nor Cl and contained an excess of OH groups of 300 wt ppm, so that the ultraviolet absorption edge shifted to longer wavelengths and the excimer light resistance was poor. .

【0029】比較例6では、a+bが55wtppmと不足し
たため、耐エキシマ光性が悪く、歪量も大きいものであ
った。
In Comparative Example 6, since a + b was insufficient at 55 wtppm, the excimer light resistance was poor and the amount of distortion was large.

【0030】比較例7では、b/aが0.3と過小であるた
め、特に耐Xe2エキシマランプ性が不良であった。以上
により、本発明のシリカガラス光学材料の効果が明らか
である。
In Comparative Example 7, since the value of b / a was as small as 0.3, the Xe 2 excimer lamp resistance was particularly poor. From the above, the effect of the silica glass optical material of the present invention is clear.

フロントページの続き Fターム(参考) 4G062 AA04 BB02 DA08 DB01 DC01 DD01 DE01 DF01 EA01 EA02 EA10 EB01 EB02 EC01 EC02 ED01 ED02 EE01 EE02 EF01 EG01 FA01 FA10 FB01 FC01 FD01 FE01 FF01 FG01 FH01 FJ01 FK01 FL01 GA01 GB01 GC01 GD01 GE02 HH01 HH03 HH05 HH07 HH08 HH09 HH11 HH12 HH13 HH15 HH17 HH20 JJ01 JJ03 JJ05 JJ06 JJ07 JJ10 KK01 KK03 KK05 KK07 KK10 MM02 MM04 NN35 Continued on the front page F term (reference) 4G062 AA04 BB02 DA08 DB01 DC01 DD01 DE01 DF01 EA01 EA02 EA10 EB01 EB02 EC01 EC02 ED01 ED02 EE01 EE02 EF01 EG01 FA01 FA10 FB01 FC01 FD01 FE01 FF01 H01 G01 F01 G01 F01 G01 HH05 HH07 HH08 HH09 HH11 HH12 HH13 HH15 HH17 HH20 JJ01 JJ03 JJ05 JJ06 JJ07 JJ10 KK01 KK03 KK05 KK07 KK10 MM02 MM04 NN35

Claims (10)

【特許請求の範囲】[Claims] 【請求項1】 波長155〜195nmのエキシマレーザ及びエ
キシマランプからの光線用シリカガラス光学材料であっ
て、超高純度であり、OH基を1〜100wtppm、H2を5×10
16〜5×1019分子/cm、及びFを10〜10,000wtppmを含
有し、F以外のハロゲンを実質的に含有せず、MoおよびW
の含有量が各0.1wtppb以下であり、かつ屈折率変動幅Δ
nが3×10-6〜3×10-7であることを特徴とするシリカ
ガラス光学材料。
1. A silica glass optical material for light from an excimer laser or an excimer lamp having a wavelength of 155 to 195 nm, which is ultra-high purity, has an OH group of 1 to 100 wt ppm, and H 2 has a concentration of 5 × 10 5.
16 to 5 × 10 19 molecules / cm 3 , containing 10 to 10,000 wtppm of F, containing substantially no halogen other than F, Mo and W
Is 0.1 wtppb or less, and the refractive index fluctuation width Δ
A silica glass optical material, wherein n is 3 × 10 −6 to 3 × 10 −7 .
【請求項2】 OH基濃度変動幅ΔOHが30wtppm以内、か
つF濃度変動幅ΔFが50wtppm以内である請求項1のシリ
カガラス光学材料。
2. The silica glass optical material according to claim 1, wherein the OH group concentration variation ΔOH is within 30 wtppm and the F concentration variation ΔF is within 50 wtppm.
【請求項3】 H2濃度変動幅ΔH2が3×1017分子/cm3
以内である請求項1または2のシリカガラス光学材料。
3. The H 2 concentration fluctuation width ΔH 2 is 3 × 10 17 molecules / cm 3
The silica glass optical material according to claim 1 or 2, wherein
【請求項4】 OH基を12〜100wtppm、H2を3×1017〜1
×1019分子/cmを含有する請求項1ないし3のいずれ
かのシリカガラス光学材料。
4. 12~100wtppm an OH group, a H 2 3 × 10 17 ~1
4. The silica glass optical material according to claim 1, which contains × 10 19 molecules / cm 3 .
【請求項5】 Fを10〜380wtppmを含有する請求項1な
いし4のいずれかのシリカガラス光学材料。
5. The silica glass optical material according to claim 1, which contains 10 to 380 wt ppm of F.
【請求項6】 不純物として、Li、NaおよびKが各5wtp
pb以下、CaおよびMgが各1wtppb以下、Cr、FeおよびNi
が各0.1wtppb以下含有する超高純度である請求項1ない
し5のいずれかのシリカガラス光学材料。
6. As impurities, Li, Na and K are each 5 wtp.
pb or less, Ca and Mg each less than 1 wtppb, Cr, Fe and Ni
6. The silica glass optical material according to claim 1, which is ultra-high purity containing 0.1 wtppb or less.
【請求項7】 7.6eV吸収帯を生成する酸素欠損型欠陥
の濃度が1×1017個/cm以下である請求項1ないし6
のいずれかのシリカガラス光学材料。
7. The concentration of oxygen-deficient defects producing a 7.6 eV absorption band is 1 × 10 17 defects / cm 3 or less.
The silica glass optical material according to any of the above.
【請求項8】 Cl含有量が10wtppm以下である請求項1
ないし7のいずれかのシリカガラス光学材料。
8. The method according to claim 1, wherein the Cl content is 10 wt ppm or less.
7. The silica glass optical material according to any one of items 7 to 7.
【請求項9】 エキシマレーザまたはエキシマランプか
らの光線の光路長が30mm以上である光学素子に用いる請
求項1ないし8のいずれかのシリカガラス光学材料。
9. The silica glass optical material according to claim 1, which is used for an optical element having an optical path length of a light beam from an excimer laser or an excimer lamp of 30 mm or more.
【請求項10】 OH基を1〜100wtppm、H2を5×1016
5×1019分子/cm、及びFを50〜10,000wtppm含有し、
そしてOH基量をa、F量をbとしたとき、aとbの合
計量が100wtppm以上であり、かつb/aが1〜1000を満
足する請求項1ないし9のいずれかのシリカガラス光学
材料。
The 10. OH group 1~100Wtppm, the H 2 5 × 10 16 ~
5 × 10 19 molecules / cm 3 , and 50 to 10,000 wtppm of F,
10. The silica glass optical device according to claim 1, wherein when the amount of OH groups is a and the amount of F is b, the total amount of a and b is 100 wtppm or more, and b / a satisfies 1 to 1000. material.
JP2000084024A 1999-10-19 2000-03-24 Silica glass optical material for excimer laser and excimer lamp Expired - Lifetime JP3472234B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2000084024A JP3472234B2 (en) 1999-10-19 2000-03-24 Silica glass optical material for excimer laser and excimer lamp

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP11296101A JP3069562B1 (en) 1999-10-19 1999-10-19 Silica glass optical material for excimer laser and excimer lamp and method for producing the same
JP2000084024A JP3472234B2 (en) 1999-10-19 2000-03-24 Silica glass optical material for excimer laser and excimer lamp

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
JP11296101A Division JP3069562B1 (en) 1999-10-19 1999-10-19 Silica glass optical material for excimer laser and excimer lamp and method for producing the same

Publications (2)

Publication Number Publication Date
JP2001114530A true JP2001114530A (en) 2001-04-24
JP3472234B2 JP3472234B2 (en) 2003-12-02

Family

ID=30002123

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2000084024A Expired - Lifetime JP3472234B2 (en) 1999-10-19 2000-03-24 Silica glass optical material for excimer laser and excimer lamp

Country Status (1)

Country Link
JP (1) JP3472234B2 (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002012441A (en) * 2000-06-27 2002-01-15 Sumitomo Metal Ind Ltd Synthetic quartz glass and its manufacturing method
JP2004083364A (en) * 2002-08-28 2004-03-18 Fujikura Ltd Synthetic quartz glass and method of manufacturing the same
JP2007084427A (en) * 2005-09-16 2007-04-05 Corning Inc Fused silica glass and method for making the same
JP2008162880A (en) * 2006-11-30 2008-07-17 Corning Inc Optical member comprising od-doped silica glass
JP2008285344A (en) * 2007-05-15 2008-11-27 Shinetsu Quartz Prod Co Ltd Copper-containing silica glass, method for manufacturing the same and xenon flash lamp using the same
JP2008544947A (en) * 2005-06-30 2008-12-11 コーニング インコーポレイテッド Synthetic silica material having low fluence dependent transmittance and method for producing the same
JP2010528960A (en) * 2007-05-09 2010-08-26 コーニング インコーポレイテッド Glass with low OH and OD levels
US8539793B2 (en) 2005-03-01 2013-09-24 Nikon Corporation Method of molding synthetic silica glass molded body

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002012441A (en) * 2000-06-27 2002-01-15 Sumitomo Metal Ind Ltd Synthetic quartz glass and its manufacturing method
JP4700787B2 (en) * 2000-06-27 2011-06-15 株式会社オハラ Synthetic quartz glass and manufacturing method thereof
JP2004083364A (en) * 2002-08-28 2004-03-18 Fujikura Ltd Synthetic quartz glass and method of manufacturing the same
US8539793B2 (en) 2005-03-01 2013-09-24 Nikon Corporation Method of molding synthetic silica glass molded body
US8679994B2 (en) 2005-03-01 2014-03-25 Nikon Corporation Method of inspecting synthetic silicia glass molded body
JP2008544947A (en) * 2005-06-30 2008-12-11 コーニング インコーポレイテッド Synthetic silica material having low fluence dependent transmittance and method for producing the same
JP2007084427A (en) * 2005-09-16 2007-04-05 Corning Inc Fused silica glass and method for making the same
JP2008162880A (en) * 2006-11-30 2008-07-17 Corning Inc Optical member comprising od-doped silica glass
JP2010528960A (en) * 2007-05-09 2010-08-26 コーニング インコーポレイテッド Glass with low OH and OD levels
JP2008285344A (en) * 2007-05-15 2008-11-27 Shinetsu Quartz Prod Co Ltd Copper-containing silica glass, method for manufacturing the same and xenon flash lamp using the same
US20100109509A1 (en) * 2007-05-15 2010-05-06 Shin-Etsu Quartz Products Co., Ltd. (Sqp) Copper-contaning silica glass, method for producing the same, and xenon flash lamp using the same
US8635886B2 (en) 2007-05-15 2014-01-28 Shin-Etsu Quartz Products Co., Ltd. Copper-containing silica glass, method for producing the same, and xenon flash lamp using the same

Also Published As

Publication number Publication date
JP3472234B2 (en) 2003-12-02

Similar Documents

Publication Publication Date Title
JP3069562B1 (en) Silica glass optical material for excimer laser and excimer lamp and method for producing the same
JP4470479B2 (en) Synthetic quartz glass for optical members and method for producing the same
US6143676A (en) Synthetic silica glass used with uv-rays and method producing the same
JP3893816B2 (en) Synthetic quartz glass and manufacturing method thereof
US6473227B1 (en) Silica glass optical material for projection lens to be utilized in vacuum ultraviolet radiation lithography, method for producing the same, and projection lens
JP4529340B2 (en) Synthetic quartz glass and manufacturing method thereof
EP2495220B1 (en) Optical member for deep ultraviolet and process for producing same
WO1993000307A1 (en) Synthetic quartz glass optical member for excimer laser and production thereof
US6689705B2 (en) Synthetic quartz glass optical material and optical member
JP3403317B2 (en) High power synthetic silica glass optical material for vacuum ultraviolet light and method for producing the same
JP4066632B2 (en) Synthetic quartz glass optical body and manufacturing method thereof
JP2005298330A (en) Synthetic quartz glass and its manufacturing method
JP3472234B2 (en) Silica glass optical material for excimer laser and excimer lamp
JP3510224B2 (en) Silica glass optical material for projection lens used in vacuum ultraviolet lithography and projection lens
JPH0616449A (en) Synthetic quartz glass optical member for excimer laser and its production
EP1067097A1 (en) Synthetic quartz glass and method for preparation thereof
JP4240709B2 (en) Synthetic quartz glass and manufacturing method thereof
JP2003183034A (en) Synthetic quartz glass for optical member and its manufacturing method
JP2003201126A (en) Synthetic quartz glass for optical member and method of manufacturing the same
JP2003201125A (en) Synthetic quartz glass and its manufacturing method
JP2002080239A (en) Synthetic quarts glass for optical piece and method of manufacturing synthetic quarts glass

Legal Events

Date Code Title Description
TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20030902

R150 Certificate of patent or registration of utility model

Ref document number: 3472234

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20080912

Year of fee payment: 5

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20200912

Year of fee payment: 17

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

EXPY Cancellation because of completion of term