JPH0238921B2 - - Google Patents
Info
- Publication number
- JPH0238921B2 JPH0238921B2 JP59198483A JP19848384A JPH0238921B2 JP H0238921 B2 JPH0238921 B2 JP H0238921B2 JP 59198483 A JP59198483 A JP 59198483A JP 19848384 A JP19848384 A JP 19848384A JP H0238921 B2 JPH0238921 B2 JP H0238921B2
- Authority
- JP
- Japan
- Prior art keywords
- refractive index
- layer
- wavelength
- index material
- light
- 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.)
- Expired - Lifetime
Links
- 239000000463 material Substances 0.000 claims description 22
- 230000003287 optical effect Effects 0.000 claims description 10
- 239000000126 substance Substances 0.000 claims description 10
- 239000000758 substrate Substances 0.000 claims description 5
- 229910017768 LaF 3 Inorganic materials 0.000 claims description 4
- 239000003989 dielectric material Substances 0.000 claims description 4
- 229910004261 CaF 2 Inorganic materials 0.000 claims description 3
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 claims description 3
- 239000010408 film Substances 0.000 description 24
- 239000010410 layer Substances 0.000 description 16
- 239000011248 coating agent Substances 0.000 description 5
- 238000000576 coating method Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 230000003595 spectral effect Effects 0.000 description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 239000010453 quartz Substances 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- 238000005299 abrasion Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000004744 fabric Substances 0.000 description 2
- 238000005286 illumination Methods 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- 229920000742 Cotton Polymers 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 229910004140 HfO Inorganic materials 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 229910010413 TiO 2 Inorganic materials 0.000 description 1
- 230000006750 UV protection Effects 0.000 description 1
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 description 1
- 229910001634 calcium fluoride Inorganic materials 0.000 description 1
- 235000013351 cheese Nutrition 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 150000002222 fluorine compounds Chemical class 0.000 description 1
- 238000007733 ion plating Methods 0.000 description 1
- 125000001449 isopropyl group Chemical group [H]C([H])([H])C([H])(*)C([H])([H])[H] 0.000 description 1
- PQXKHYXIUOZZFA-UHFFFAOYSA-M lithium fluoride Inorganic materials [Li+].[F-] PQXKHYXIUOZZFA-UHFFFAOYSA-M 0.000 description 1
- 229910001635 magnesium fluoride Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000012788 optical film Substances 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- PUZPDOWCWNUUKD-UHFFFAOYSA-M sodium fluoride Inorganic materials [F-].[Na+] PUZPDOWCWNUUKD-UHFFFAOYSA-M 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 238000001771 vacuum deposition Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
- G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
- G02B1/11—Anti-reflection coatings
- G02B1/113—Anti-reflection coatings using inorganic layer materials only
- G02B1/115—Multilayers
Description
〔発明の分野〕
本発明は光反射防止膜に関し、特に真空紫外線
に対して良好な反射防止作用を有する膜体に関す
る。
〔従来技術〕
半導体露光装置は、焼付の方式からみて、密着
（又はプロキシミテイー）方式と投影焼付方式と
に分けられ、装置の解像力は、密着露光の場合に
は光源波長の平方根に比例し、また投影露光の場
合には光源波長に比例する。このため、露光装置
の解像力を高める目的から、光源の短波長化を図
る必要があり、現今では200〜270nｍの紫外線を
利用した装置が実用化されている。しかし、将来
的には更に解像力を高める必要があり、波長
200nｍ以下の真空紫外線を用いる必要がでてく
る。
ところで、半導体露光装置の照明系において、
レンズ面での反射に起因するゴーストが像面の照
明ムラを起すという問題がある。このため、従来
からレンズ面を誘電体の単層ないし多層からなる
反射防止膜で被覆することは行なわれているが、
真空紫外線領域において作用する反射防止膜は殆
どなく、僅かに特公昭50−40668号、Optical
Engineering Vol.18、No.１（1979）等に見られる
が、これらも十分な反射防止機能を果たすものと
は言い難い。
〔発明の目的〕
本発明の１つの目的は、真空紫外線に対して良
好な反射防止作用を有する反射防止膜を提供する
ことにある。
本発明の他の目的は、真空紫外線に対して良好
な反射防止作用を有すると共に、物理的、化学的
に安定な反射防止膜を提供することにある。
上記目的は、フツ化物系の誘電体材料の内、波
長160〜230nｍの光に対し屈折率が1.5以下の低屈
折率物質と屈折率が1.6〜1.8の中間屈折率物質と
を用い、波長160〜230nｍの範囲内の任意の設計
基準波長λ0に対し、前記波長の光を透過する物質
からなる基体上に前記低屈折率物質からなる光学
的膜厚約λ0／２の第１層、前記中間屈折率物質か
らなる光学的膜厚約λ0／４の第２層、次いで前記
低屈折率物質からなる光学的膜厚約λ0／４の第３
層の順で積層された３層構造を有することを特徴
とする光反射防止膜によつて構成される。
〔発明の具体的説明〕
真空紫外線用反射防止膜は、その膜材料が設
計、製作上大きな制約となる。すなわち反射防止
膜の膜材料は、真空紫外線に対し、透明かつ安定
な物質でなければならない。真空紫外線透過材料
としてはMgF2、CaF2、LiF、NaF、LaF3、
NdF3等のフツ化物が知られている。一方、
Al2O3、SiO2、HfO2等の一部の酸化物は、比較
的短波長まで透過するが波長200nｍ以下では吸
収が大きくなり透過しなくなる。また可視域での
反射防止膜に使用されるZrO2、TiO2、CeO2等の
高屈折率物質は、吸収が大きく透過しないために
使用することができない。従つて本発明の光反射
防止膜は、フツ化物系の誘電体材料で構成する。
このうち、本発明で使用する前記低屈折率物質
としては、MgF2、CaF2、LiF、及びNa3AlF6か
ら選ばれる物質、また前記中間屈折率物質として
は、LaF3及びNdF3から選ばれる物質が好適であ
る。
本発明の光反能防止膜は、第１図に示した如く
３層構造を有する光反射防止膜である。
第１図において、１は波長160〜230nｍの光を
透過する物質からなる基体であり、具体的には例
えば合成石英、人工水晶、CaF2、MgF2等の結晶
などからなるレンズ等光学デバイスである。基体
１上に積層された２，４は低屈折率物質の層、３
は中間屈折率物質の層であり、これらを設層する
には、通常真空蒸着法（イオンプレーテイング、
スパツタリング等を包含する。）が用いられる。
なお、第１図には平板状の膜体を示したが、膜の
形状はこれに限定されず、円筒面状、球面状、凹
面状、凸面状等の基体表面の形状に応じて任意に
設計することができる。
本発明の光反射防止膜は、基本的には1/2λ0−
１／４λ0−1/2λ0（λ0は160〜230nｍの範囲内で選ば
れる任意の設計基準波長である。）の構成をとり、
第１層乃至第３層の光学的膜厚は、それぞれ約1/
２λ0、約1/4λ0及び約1/4λ0である。基体側の1/2λ0
層は本質的にはアブセンテイー層である。なお、
合成石英：ｎ＝1.448＋7.51／λ−126.5
MgF2：ｎ＝1.348＋10.03／λ−69
LaF3：ｎ＝1.574＋15.4／λ−69
[Field of the Invention] The present invention relates to a light antireflection film, and particularly to a film body having a good antireflection effect against vacuum ultraviolet rays. [Prior Art] Semiconductor exposure equipment is divided into two types in terms of the printing method: the contact (or proximity) method and the projection printing method. In the case of contact exposure, the resolution of the device is proportional to the square root of the light source wavelength. , and in the case of projection exposure, it is proportional to the light source wavelength. Therefore, in order to improve the resolution of the exposure apparatus, it is necessary to shorten the wavelength of the light source, and devices that utilize ultraviolet light of 200 to 270 nm are currently in practical use. However, in the future it will be necessary to further improve the resolution, and the wavelength
It becomes necessary to use vacuum ultraviolet light with a wavelength of 200 nm or less. By the way, in the illumination system of semiconductor exposure equipment,
There is a problem in that ghosts caused by reflection on the lens surface cause uneven illumination on the image surface. For this reason, it has been conventional practice to coat the lens surface with an anti-reflection coating consisting of a single layer or multiple layers of dielectric material.
There are almost no antireflection films that act in the vacuum ultraviolet region, and only a few
Engineering Vol. 18, No. 1 (1979), etc., but these too cannot be said to have a sufficient antireflection function. [Object of the Invention] One object of the present invention is to provide an antireflection film that has a good antireflection effect against vacuum ultraviolet rays. Another object of the present invention is to provide an antireflection film that has a good antireflection effect against vacuum ultraviolet rays and is physically and chemically stable. The above purpose is achieved by using a low refractive index material with a refractive index of 1.5 or less and an intermediate refractive index material with a refractive index of 1.6 to 1.8 for light with a wavelength of 160 to 230 nm among fluoride dielectric materials. A first layer with an optical thickness of about λ 0 /2 made of the low refractive index material on a substrate made of a material that transmits light of the wavelength for an arbitrary design reference wavelength λ 0 in the range of ~230 nm; A second layer made of the intermediate refractive index material and having an optical thickness of about λ 0 /4, and then a third layer made of the low refractive index material and having an optical thickness of about λ 0 /4.
It is composed of an anti-reflection film characterized by having a three-layer structure in which layers are laminated in this order. [Detailed Description of the Invention] The anti-reflection coating for vacuum ultraviolet rays has a major restriction in design and production due to the coating material. That is, the film material of the antireflection film must be transparent and stable to vacuum ultraviolet rays. Vacuum ultraviolet transmitting materials include MgF 2 , CaF 2 , LiF, NaF, LaF 3 ,
Fluorides such as NdF 3 are known. on the other hand,
Some oxides, such as Al 2 O 3 , SiO 2 , HfO 2 , etc., transmit light up to relatively short wavelengths, but absorb at wavelengths of 200 nm or less and are no longer transmitted. Further, high refractive index materials such as ZrO 2 , TiO 2 , CeO 2 and the like used for anti-reflection films in the visible region cannot be used because they are highly absorbed and do not transmit. Therefore, the antireflection film of the present invention is composed of a fluoride-based dielectric material. Among these, the low refractive index substance used in the present invention is selected from MgF 2 , CaF 2 , LiF, and Na 3 AlF 6 , and the intermediate refractive index substance is selected from LaF 3 and NdF 3 . Preferred are substances that The antireflection film of the present invention is an antireflection film having a three-layer structure as shown in FIG. In Figure 1, 1 is a substrate made of a substance that transmits light with a wavelength of 160 to 230 nm, and specifically, it is an optical device such as a lens made of synthetic quartz, artificial quartz, crystals such as CaF2 , MgF2 , etc. be. Laminated on the substrate 1 are layers 2 and 4 of a low refractive index material;
is a layer of intermediate refractive index material, and these layers are usually deposited using vacuum evaporation methods (ion plating,
Includes sputtering, etc. ) is used.
Although a flat film body is shown in FIG. 1, the shape of the film is not limited to this, and may be arbitrarily selected according to the shape of the base surface, such as cylindrical, spherical, concave, or convex. can be designed. The antireflection film of the present invention basically has 1/2λ 0 −
It has a configuration of 1/4λ 0 −1/2λ 0 (λ 0 is an arbitrary design reference wavelength selected within the range of 160 to 230 nm),
The optical thickness of the first layer to the third layer is approximately 1/1, respectively.
2λ 0 , about 1/4λ 0 and about 1/4λ 0 . 1/2λ on the base side 0
The layer is essentially an absentee layer. In addition,
Synthetic quartz: n=1.448+7.51/λ-126.5 MgF 2 : n=1.348+10.03/λ-69 LaF 3 : n=1.574+15.4/λ-69
【表】
かくして得られた光反射防止膜の分光特性を第
２図に示した。これによれば、波長160〜230nｍ
の範囲で反射率を１％以下、特に波長165〜215n
ｍの範囲で反射率を0.5％以下に抑さえることが
できた。従つて、通常使用する真空紫外線は
180nｍ付近であるため、本発明の光反射防止膜
によれば十分に反射率を低く抑さえることができ
る。
次に、耐久性については、耐溶剤テストとして
アセトン、イソプロピル、アルコール、メタノー
ルを用い、作製した光反射防止膜を付したレンズ
表面をクリーニングしたが分光特性、外観上の変
化が見られず、十分耐溶剤性があることが確かめ
られた。また、スコツチテープによる密着性テス
ト、綿布（チーズクロス）による耐摩耗テストの
結果も剥離、クラツク等の外観上の欠陥ならびに
反射率の変化は見られなかつた。耐湿性について
も45℃、相対湿度95％の恒温恒湿槽に1000時間以
上置いた後も、反射率の低下、腐食等の化学的変
化は起こらなかつた。さらに、真空紫外光の照射
に対しても、何ら劣化することはなかつた。
実施例 ２
λ0＝200nｍ、第１層の膜材料（物質）をLiFと
し、第２表に示した屈折率及び最適化された光学
的膜厚とした以外は実施例１と同様にして、光反
射防止膜を作製した。
かくして得られた光反射防止膜の分光特性を第
３図に示した。本実施例においても、実施例１の
光反射防止膜と同等の光学的性質並びに化学的、
物理的安定性を有する光反射防止膜が得られた。[Table] The spectral characteristics of the antireflection film thus obtained are shown in FIG. According to this, the wavelength is 160 to 230 nm.
Reflectance is 1% or less in the range of 165 to 215n.
It was possible to suppress the reflectance to 0.5% or less in the range of m. Therefore, the normally used vacuum ultraviolet light is
Since the wavelength is around 180 nm, the antireflection film of the present invention can suppress the reflectance sufficiently low. Next, regarding durability, we used acetone, isopropyl, alcohol, and methanol in a solvent resistance test to clean the surface of the lens with the anti-reflection coating, but no changes were observed in the spectral characteristics or appearance. It was confirmed that it has solvent resistance. Further, as a result of an adhesion test with Scotch tape and an abrasion test with cotton cloth (cheese cloth), no external defects such as peeling or cracks, and no change in reflectance were observed. Regarding humidity resistance, even after being placed in a constant temperature and humidity chamber at 45°C and 95% relative humidity for over 1,000 hours, no chemical changes such as a decrease in reflectance or corrosion occurred. Furthermore, no deterioration occurred even when irradiated with vacuum ultraviolet light. Example 2 Same as Example 1 except that λ 0 = 200 nm, the film material (substance) of the first layer was LiF, and the refractive index and optimized optical film thickness shown in Table 2 were used. An anti-reflection film was produced. The spectral characteristics of the antireflection film thus obtained are shown in FIG. This example also has the same optical properties and chemical properties as the antireflection film of Example 1.
A light antireflection film with physical stability was obtained.
【表】【table】
以上説明したように、本発明の光反射防止膜
は、光学的には真空紫外線をはじめとして所望す
る波長の光に対してレンズ等基体表面の反射を低
くおさえ、ゴースト等の問題を解決するという優
れた光学的性質を持つている。さらに、耐溶剤
性、耐湿性に優れるという化学的安定性に富むと
同時に密着性・耐摩耗性、耐紫外線性など物理的
安定性にも優れており、実用的にきわめて有用で
ある。
As explained above, the anti-reflection coating of the present invention optically suppresses the reflection of the surface of a substrate such as a lens against light of a desired wavelength, including vacuum ultraviolet rays, and solves problems such as ghosting. It has excellent optical properties. Furthermore, it is highly chemically stable with excellent solvent resistance and moisture resistance, and at the same time has excellent physical stability such as adhesion, abrasion resistance, and ultraviolet resistance, making it extremely useful for practical purposes.
第１図は、本発明の光反射防止膜の構成を説明
するための図、第２図及び第３図は、実施例１〜
２で作製した光反射防止膜の分光特性を示すため
の曲線図である。
１……基体、２，４……低屈折率物質層、３…
…中間屈折率物質層。
FIG. 1 is a diagram for explaining the structure of the antireflection film of the present invention, and FIGS. 2 and 3 are examples 1 to 3.
FIG. 2 is a curve diagram showing the spectral characteristics of the antireflection film prepared in step 2. 1... Base body, 2, 4... Low refractive index material layer, 3...
...Intermediate refractive index material layer.
Claims (1)
230nｍの光に対し屈折率が1.5以下の低屈折率物
質と屈折率が1.6〜1.8の中間屈折率物質とを用
い、波長160〜230nｍの範囲内の任意の設計基準
波長λ0に対し、前記波長の光を透過する物質から
なる基体上に前記低屈折率物質からなる光学的膜
厚約λ0／２の第１層、前記中間屈折率物質からな
る光学的膜厚約λ0／４の第２層、次いで前記低屈
折率物質からなる光学的膜厚約λ0／４の第３層の
順で積層された３層構造を有することを特徴とす
る光反射防止膜。 ２ 低屈折率物質が、MgF2、CaF2、LiF及び
Na3AlF6から選ばれる物質であり、中間屈折率
物質がLaF3及びNdF3から選ばれる物質である特
許請求の範囲第１項記載の光反射防止膜。[Claims] 1 Among fluoride-based dielectric materials, wavelength 160~
For light of 230 nm, a low refractive index material with a refractive index of 1.5 or less and an intermediate refractive index material with a refractive index of 1.6 to 1.8 are used, and for any design standard wavelength λ 0 within the wavelength range of 160 to 230 nm, the above A first layer made of the low refractive index material and having an optical thickness of about λ 0 /2, and a first layer made of the intermediate refractive index material and having an optical thickness of about λ 0 /4 on a substrate made of a material that transmits light of a certain wavelength. A light antireflection film characterized in that it has a three-layer structure in which the second layer is laminated in this order, and then the third layer is made of the low refractive index material and has an optical thickness of about λ 0 /4. 2 The low refractive index material is MgF 2 , CaF 2 , LiF and
The anti-reflection film according to claim 1, wherein the anti-reflection film is a substance selected from Na 3 AlF 6 and the intermediate refractive index substance is a substance selected from LaF 3 and NdF 3 .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59198483A JPS6177002A (en) | 1984-09-25 | 1984-09-25 | Optical antireflecting film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59198483A JPS6177002A (en) | 1984-09-25 | 1984-09-25 | Optical antireflecting film |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6177002A JPS6177002A (en) | 1986-04-19 |
| JPH0238921B2 true JPH0238921B2 (en) | 1990-09-03 |
Family
ID=16391860
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59198483A Granted JPS6177002A (en) | 1984-09-25 | 1984-09-25 | Optical antireflecting film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6177002A (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2586509B2 (en) * | 1987-09-01 | 1997-03-05 | ミノルタ株式会社 | Anti-reflective coating |
| JP2590924B2 (en) * | 1987-09-01 | 1997-03-19 | ミノルタ株式会社 | Anti-reflective coating |
| JPH06140707A (en) * | 1992-10-27 | 1994-05-20 | Showa Koki Seizo Kk | Antireflection film of deliquescent optical crystal |
| US5661596A (en) * | 1994-02-03 | 1997-08-26 | Canon Kabushiki Kaisha | Antireflection film and exposure apparatus using the same |
| JPH08220304A (en) | 1995-02-13 | 1996-08-30 | Tadahiro Omi | Optical product, exposure device or optical system using same, and production thereof |
| JP3924806B2 (en) * | 1996-06-10 | 2007-06-06 | 株式会社ニコン | Anti-reflection coating |
| KR100709045B1 (en) * | 1999-11-05 | 2007-04-18 | 아사히 가라스 가부시키가이샤 | Antireflection base for ultraviolet and vacuum ultraviolet regions |
| JP2004302113A (en) * | 2003-03-31 | 2004-10-28 | Nikon Corp | Antireflection film, optical member, optical system and projection exposure apparatus, and manufacturing method for antireflection film |
| JP2005257769A (en) * | 2004-03-09 | 2005-09-22 | Canon Inc | Optical thin film, optical element, exposure apparatus using same, and exposure method |
| KR20100095134A (en) | 2009-02-20 | 2010-08-30 | 엘지이노텍 주식회사 | Light emitting device and method for fabricating the same |
-
1984
- 1984-09-25 JP JP59198483A patent/JPS6177002A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6177002A (en) | 1986-04-19 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term |