JPH02251912A - Production of thin-film waveguide type optical isolator - Google Patents
Production of thin-film waveguide type optical isolatorInfo
- Publication number
- JPH02251912A JPH02251912A JP7193589A JP7193589A JPH02251912A JP H02251912 A JPH02251912 A JP H02251912A JP 7193589 A JP7193589 A JP 7193589A JP 7193589 A JP7193589 A JP 7193589A JP H02251912 A JPH02251912 A JP H02251912A
- Authority
- JP
- Japan
- Prior art keywords
- film
- substrate
- single crystal
- waveguide
- crystal film
- 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.)
- Pending
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 33
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 10
- 239000010409 thin film Substances 0.000 title claims description 32
- 239000013078 crystal Substances 0.000 claims abstract description 77
- 239000000758 substrate Substances 0.000 claims abstract description 58
- 239000010410 layer Substances 0.000 claims abstract description 30
- 239000011247 coating layer Substances 0.000 claims abstract description 19
- 239000000463 material Substances 0.000 claims abstract description 9
- 239000010408 film Substances 0.000 claims description 71
- 238000000034 method Methods 0.000 claims description 33
- 238000005530 etching Methods 0.000 abstract description 12
- 238000005498 polishing Methods 0.000 abstract description 9
- 238000004544 sputter deposition Methods 0.000 abstract description 9
- 238000010884 ion-beam technique Methods 0.000 abstract description 4
- 229920002120 photoresistant polymer Polymers 0.000 abstract description 4
- 238000003486 chemical etching Methods 0.000 abstract description 2
- 239000002223 garnet Substances 0.000 description 14
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 12
- 230000004907 flux Effects 0.000 description 12
- 229910052751 metal Inorganic materials 0.000 description 12
- 239000002184 metal Substances 0.000 description 12
- 229910052760 oxygen Inorganic materials 0.000 description 12
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 9
- 239000010936 titanium Substances 0.000 description 8
- 229910052727 yttrium Inorganic materials 0.000 description 8
- 229910052742 iron Inorganic materials 0.000 description 7
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 6
- 239000007791 liquid phase Substances 0.000 description 5
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 4
- 238000010583 slow cooling Methods 0.000 description 4
- 239000002002 slurry Substances 0.000 description 4
- GYHNNYVSQQEPJS-UHFFFAOYSA-N Gallium Chemical compound [Ga] GYHNNYVSQQEPJS-UHFFFAOYSA-N 0.000 description 3
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 3
- 229910052797 bismuth Inorganic materials 0.000 description 3
- 238000005229 chemical vapour deposition Methods 0.000 description 3
- 229910052733 gallium Inorganic materials 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 238000007738 vacuum evaporation Methods 0.000 description 3
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- 229910052772 Samarium Inorganic materials 0.000 description 2
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- MTRJKZUDDJZTLA-UHFFFAOYSA-N iron yttrium Chemical group [Fe].[Y] MTRJKZUDDJZTLA-UHFFFAOYSA-N 0.000 description 2
- 238000002955 isolation Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 238000001451 molecular beam epitaxy Methods 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 239000000382 optic material Substances 0.000 description 2
- KZUNJOHGWZRPMI-UHFFFAOYSA-N samarium atom Chemical compound [Sm] KZUNJOHGWZRPMI-UHFFFAOYSA-N 0.000 description 2
- 229910019655 synthetic inorganic crystalline material Inorganic materials 0.000 description 2
- 238000001771 vacuum deposition Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- VZSRBBMJRBPUNF-UHFFFAOYSA-N 2-(2,3-dihydro-1H-inden-2-ylamino)-N-[3-oxo-3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propyl]pyrimidine-5-carboxamide Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C(=O)NCCC(N1CC2=C(CC1)NN=N2)=O VZSRBBMJRBPUNF-UHFFFAOYSA-N 0.000 description 1
- 229910021532 Calcite Inorganic materials 0.000 description 1
- 229910052688 Gadolinium Inorganic materials 0.000 description 1
- 229910052779 Neodymium Inorganic materials 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- JNDMLEXHDPKVFC-UHFFFAOYSA-N aluminum;oxygen(2-);yttrium(3+) Chemical compound [O-2].[O-2].[O-2].[Al+3].[Y+3] JNDMLEXHDPKVFC-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005234 chemical deposition Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- ZSOJHTHUCUGDHS-UHFFFAOYSA-N gadolinium iron Chemical compound [Fe].[Gd] ZSOJHTHUCUGDHS-UHFFFAOYSA-N 0.000 description 1
- ZPDRQAVGXHVGTB-UHFFFAOYSA-N gallium;gadolinium(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Ga+3].[Gd+3] ZPDRQAVGXHVGTB-UHFFFAOYSA-N 0.000 description 1
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 description 1
- 238000001552 radio frequency sputter deposition Methods 0.000 description 1
- 238000007788 roughening Methods 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 229910019901 yttrium aluminum garnet Inorganic materials 0.000 description 1
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 description 1
- 239000011787 zinc oxide Substances 0.000 description 1
Landscapes
- Optical Integrated Circuits (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、光通信等の分野における光アイソレータ、特
に薄膜導波型光アイソレータの製造方法に関する。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing an optical isolator in the field of optical communications, and particularly a thin film waveguide type optical isolator.
（従来の技術及び解決すべき課題）
現在実用化されている光アイソレータとしては、ガーネ
ット等の磁気光学結晶に方解石等の偏光子を組合せた、
いわゆるバルク型のものがあり、また、液相エピタキシ
ャル法で作成したガーネット厚膜を用いたいわゆる原模
型アイソレータが開発されている。又近年は、更に量産
化に優れ、低コスト化が可能で、且つ信頼が高いという
特徴を有する、磁気光学薄膜導波路を用いた薄膜導波型
光アイソレータが研究されている（例えば特公昭６０−
４９２８１号公報、特開昭６０−１０７６１６号公報参
照）。(Prior art and problems to be solved) Optical isolators currently in practical use include magneto-optic crystals such as garnet combined with polarizers such as calcite.
There is a so-called bulk type isolator, and a so-called original model isolator using a garnet thick film created by a liquid phase epitaxial method has been developed. In addition, in recent years, thin film waveguide optical isolators using magneto-optic thin film waveguides have been studied, which have the characteristics of being easier to mass produce, lowering costs, and being highly reliable (for example, in Japanese Patent Publication No. 60 −
49281, JP-A-60-107616).
そして、本出願人は、先に薄膜導波型光アイソレータと
して、ガーネット結晶基板、該ガーネット結晶基板上に
形成され、磁気光学材料からなる導波層及び該導波層上
に形成される被覆層とからなる薄膜導波型光アイソレー
タを開発した（特願昭６３−１４４６９４号）。The present applicant has previously developed a thin film waveguide type optical isolator including a garnet crystal substrate, a waveguide layer formed on the garnet crystal substrate and made of a magneto-optic material, and a coating layer formed on the waveguide layer. We have developed a thin film waveguide type optical isolator consisting of (Japanese Patent Application No. 144694/1983).
しかして、この新たに開発された薄膜導波型光アイソレ
ータは、結晶基板の上に導波層及び被覆層を形成して製
造するものであるが、その際に、導波層をチャンネル型
の光導波路で形成させる場合には、育成させた単結晶膜
に化学的エツチングを施す工程が必要であり、この工程
で失敗すれば貴重な単結晶膜を無駄にする問題点があっ
た。However, this newly developed thin film waveguide optical isolator is manufactured by forming a waveguide layer and a coating layer on a crystal substrate, but at that time, the waveguide layer is formed into a channel-type optical isolator. When forming an optical waveguide, a process of chemically etching the grown single crystal film is required, and if this process fails, the valuable single crystal film will be wasted.
本発明はこの欠点を解消して、チャンネル型特に埋め込
み型の先導波路を導波層とする薄膜導波型光アイソレー
タを製造する方法を提供するにある。The present invention eliminates this drawback and provides a method for manufacturing a thin film waveguide type optical isolator having a channel type, particularly a buried type, leading waveguide as a waveguide layer.
（課題を解決するための手段）
即ち、本発明は、基板表面に凹溝を設け、この凹溝のみ
に磁気光学材料の結晶膜を育成させて導波層を形成し、
次いで少なくとも導波層上に被覆層を形成することを特
徴とする薄膜導波型光アイソレータの製造方法である。(Means for Solving the Problems) That is, the present invention provides a groove on the surface of a substrate, and forms a waveguide layer by growing a crystal film of a magneto-optical material only in the groove.
This method of manufacturing a thin film waveguide type optical isolator is characterized in that a coating layer is then formed on at least the waveguide layer.
本発明においては、基板表面に光導波路形状の凹状の溝
（以下、凹溝という）を設け、この凹溝のみに結晶膜を
育成させ、その後に、この凹溝に育成した結晶膜の上の
み、もしくは基板表面全体を被覆層で覆うので、育成し
た結晶膜に化学的工・ンチングを施して不用部分を除去
して整形する工程を必要としない。従って、本発明によ
れば折角育成した単結晶膜を化学エツチングの際の失敗
によって基板共々駄目にしてしまう恐れがなくなる。In the present invention, a concave groove in the shape of an optical waveguide (hereinafter referred to as a concave groove) is provided on the substrate surface, a crystal film is grown only in this concave groove, and then a crystal film is grown only on the crystal film grown in this concave groove. Alternatively, since the entire surface of the substrate is covered with a coating layer, there is no need to chemically process or etch the grown crystal film to remove unnecessary portions and shape it. Therefore, according to the present invention, there is no possibility that the single crystal film that has been painstakingly grown will be damaged together with the substrate due to failure during chemical etching.
そして本発明方法によれば、たとえ基板に凹溝を形成さ
せる際に失敗があっても、基板の損失のみで済む利点が
ある。According to the method of the present invention, even if there is a failure in forming the groove on the substrate, there is an advantage that only the loss of the substrate is caused.
本発明で用いる基板としては、ガドリニウム・ガリウム
・ガーネット（ＧＧＧ、 Ｇｄ、Ｇａ、Ｏ，、）、サマ
リウム・ガリウム・ガーネット（ＳｎｎＧＧ、 Ｓ＋ｎ
、Ｇａ、Ｏ，、）、ネオジム・ガリウム・ガーネット（
ＮｄＧＧ、 ＮｄおＧａｓ Ｏ＋ ｒ ）などである。Substrates used in the present invention include gadolinium gallium garnet (GGG, Gd, Ga, O, .), samarium gallium garnet (SnnGG, S+n), and samarium gallium garnet (SnnGG, S+n).
, Ga, O, ), neodymium gallium garnet (
NdGG, NdGasO+r), etc.
基板上に光導波路形状の凹溝を設けるには、基板にレジ
ストパターンで先導波路形成部分にフォトレジスト膜を
形成し、次いで基板全面にスパッタリングなどでチタン
等の金属膜を形成し、その後レジストパターン上の金属
膜をレジストと共に除去し、すなわち光導波路形成部分
のみを露出させ、イオンビームエツチングなどで光導波
路形成部分を凹溝になし、そして最後に残った金属膜を
除去することにより行なう。この凹溝の内表面は鏡面状
態にある。To provide a groove in the shape of an optical waveguide on a substrate, a photoresist film is formed on the substrate in the area where the leading waveguide will be formed using a resist pattern, then a metal film such as titanium is formed on the entire surface of the substrate by sputtering, etc., and then a resist pattern is formed on the substrate. This is done by removing the upper metal film together with the resist, in other words, exposing only the optical waveguide forming part, making the optical waveguide forming part into a groove by ion beam etching, and finally removing the remaining metal film. The inner surface of this groove has a mirror surface.
このようにして設けた基板表面の凹溝のみに結晶膜を形
成させ、更にその上に被覆層を形成させるには、例えば
次の方法による。In order to form a crystal film only in the grooves on the surface of the substrate provided in this manner and further form a coating layer thereon, the following method may be used, for example.
その第１の方法は、基板表面に凹溝を設けた後、基板表
面全面に磁気光学材料の結晶膜を育成させ、その後に凹
溝以外に育成した結晶膜を除去して凹溝のみに結晶膜を
形成させて導波路、即ち導波層を設け、次いで基板表面
全体に被覆層を形成する方法である。The first method is to form grooves on the substrate surface, grow a crystal film of magneto-optical material over the entire surface of the substrate, and then remove the grown crystal film in areas other than the grooves to create crystals only in the grooves. This method involves forming a film to provide a waveguide, that is, a waveguide layer, and then forming a coating layer over the entire surface of the substrate.
この方法について更に詳しく説明する。まず、基板表面
に凹溝を設けた後、基板表面全面に形成させる結晶膜の
材料としては、イツトリウム・鉄ガーネット（ＹＩＧ、
Ｙ、Ｆｅ、Ｏｏ）、イツトリウム・アルミニウムガー
ネット（ＹＡＧ、 Ｙ、ＡＱ、Ｏ，、）、またはその置
換体（ガドリウム・鉄ガーネット（ＧｄｌＧ）など）、
部分置換体（（Ｂｔ、Ｙ）、Ｆｅ、Ｏ，、）など）のガ
ーネット結晶膜などが用いられる。This method will be explained in more detail. First, after forming grooves on the substrate surface, the material for the crystal film to be formed on the entire surface of the substrate is yttrium iron garnet (YIG,
Y, Fe, Oo), yttrium/aluminum garnet (YAG, Y, AQ, O,,), or its substitutes (gadolium/iron garnet (GdlG), etc.),
A garnet crystal film of a partially substituted product ((Bt, Y), Fe, O, etc.) is used.
これらの単結晶膜の育成は、液相エピタキシャル法、化
学堆積法（ＣＶＤ法）、分子線エピタキシャル法（ＭＢ
Ｅ法）、真空蒸着法、スパッタリング法などで行なう。These single crystal films can be grown using liquid phase epitaxial method, chemical deposition method (CVD method), molecular beam epitaxial method (MB
E method), vacuum evaporation method, sputtering method, etc.
この単結晶の育成操作によって、単結晶膜は例えば図に
示す様に育成する。すなわち第１図は光導波路形状の凹
溝２を形成した基板ｌの断面図である。この基板ｌに単
結晶膜３を育成させると、第２図の如く、光導波路形成
部分の凹溝内にも単結晶膜が育成し、また凹溝以外の部
分にも単結晶膜が育成する。By this single crystal growing operation, a single crystal film is grown, for example, as shown in the figure. That is, FIG. 1 is a cross-sectional view of a substrate l on which a groove 2 in the shape of an optical waveguide is formed. When the single crystal film 3 is grown on this substrate 1, as shown in Fig. 2, the single crystal film is grown in the grooves of the optical waveguide forming part, and also in the parts other than the grooves. .
したがって、この光導波路形成部分の凹溝以外の部分に
形成された単結晶膜を除去すると、第３図に示すごとき
、凹溝内のみに単結晶膜が存在する、すなわち光導波路
が存在する基板が得られる。Therefore, when the single crystal film formed in the part other than the groove of the optical waveguide forming part is removed, the single crystal film exists only in the groove as shown in FIG. 3, that is, the substrate where the optical waveguide exists. is obtained.
４は単結晶膜である。4 is a single crystal film.
凹溝以外の部分に形成された単結晶膜の除去は、研磨に
より行なうのが好ましい。この研磨に当っては、研磨液
を用いて行なうのが好ましい。そして研磨液として、基
板を切削することの少ない研磨材粒子のスラリーを用い
ると、基板の平行度がそのまま先導波路の平行度となる
ので非常に有利である。この研磨材粒子としては例えば
１，０．が用いられる。It is preferable to remove the single crystal film formed in the portion other than the groove by polishing. This polishing is preferably carried out using a polishing liquid. It is very advantageous to use a slurry of abrasive particles that rarely cuts the substrate as the polishing liquid, since the parallelism of the substrate directly corresponds to the parallelism of the leading waveguide. The abrasive particles may be, for example, 1,0. is used.
このようにして、表面の凹溝のみに結晶膜が形成した基
板が得られ、この凹溝内に形成された結晶膜の表面も、
研磨によって鏡面状態になっているので、その上に被覆
層を円滑に形成させることができる。第４図は被覆層を
形成させた状態を示す。５は被覆層である。In this way, a substrate is obtained in which a crystal film is formed only in the grooves on the surface, and the surface of the crystal film formed in the grooves is also
Since it is polished to a mirror surface, a coating layer can be smoothly formed thereon. FIG. 4 shows the state in which the coating layer has been formed. 5 is a covering layer.
被覆層としては、イツトリウム・鉄ガーネット（ＹＩＧ
％Ｙ、 Ｆｅ、 Ｏｏ）、イツトリウム・アルミニウム
ガーネット（ＹＡＧ、 Ｙ、ＡＱ、Ｏｏ）、またはその
置換体（ガドリニウム・鉄ガーネット（ＧｄＩＧ）など
）、部分置換体（（Ｂｔ＊ ｙ） ＊ Ｆｅ、 ｏ、
ｆなど）のガーネット結晶膜などが用いられる。そして
被覆層の屈折率は導波層の屈折率よりも０．００５〜０
．０５小さくする。又その厚さは空気の影響がない程度
の厚さ、即ち５μｍ以上であることが好ましい。この厚
さが５μｍ以下の場合には、その上に上部層として例え
ば酸化亜鉛層を形成するのが好ましい。被覆層は必ずし
も良好な結晶性を有する必要はなく、液相エピタキシャ
ル法、ＣＶＤ法、ＭＢＥ法、真空蒸着法、スパッタリン
グ法などを用いて容易に形成できる。The coating layer is yttrium iron garnet (YIG).
%Y, Fe, Oo), yttrium aluminum garnet (YAG, Y, AQ, Oo), or its substituted products (gadolinium iron garnet (GdIG), etc.), partially substituted products ((Bt* y) * Fe, o ,
A garnet crystal film such as f) is used. The refractive index of the coating layer is 0.005 to 0.0% higher than that of the waveguide layer.
．． 05 Make it smaller. The thickness is preferably such that it is not affected by air, that is, 5 μm or more. When this thickness is 5 μm or less, it is preferable to form, for example, a zinc oxide layer thereon as an upper layer. The coating layer does not necessarily have to have good crystallinity, and can be easily formed using a liquid phase epitaxial method, a CVD method, an MBE method, a vacuum evaporation method, a sputtering method, or the like.
又、第２の方法は、基板表面に凹溝を設けた後、凹溝以
外の部分を粗面状態となし、次いで基板全面に磁気光学
材料の結晶膜育成操作を施して凹溝内のみに結晶膜（導
波層）を形成させ、その後少なくとも導波層上に被覆層
を形成させる方法である。The second method is to provide grooves on the surface of the substrate, roughen the area other than the grooves, and then grow a crystalline film of magneto-optical material on the entire surface of the substrate to form a crystalline film only in the grooves. This is a method in which a crystal film (waveguide layer) is formed, and then a coating layer is formed at least on the waveguide layer.
この方法について詳しく説明する。This method will be explained in detail.
基板表面に凹溝を設けた後、凹溝部以外の部分を粗面状
態にするために施す粗面加工は、凹溝部を保護して化学
薬品で処理して行うこともできるが、機械的に、すなわ
ち例えば研磨紙でラッピングすることにより行うのが好
ましい。研磨紙としては＃３０００より粗いものを用い
るのが好ましい。After grooves have been formed on the surface of the substrate, surface roughening can be performed to roughen the parts other than the grooves, which can be done by protecting the grooves and treating them with chemicals, but it is also possible to process them mechanically. That is, it is preferable to carry out, for example, wrapping with abrasive paper. It is preferable to use abrasive paper coarser than #3000.
基板表面の凹溝内に育成させる結晶膜の材料としては、
先に第１の方法で述べたと同じものが使用される。また
結晶膜育成操作も第１の方法で述べたと同じ方法が採用
できる。The material for the crystal film grown in the grooves on the substrate surface is as follows:
The same as previously described in the first method is used. Furthermore, the same method as described in the first method can be used for the crystal film growth operation.
そして、液相エピタキシャル法、ＣＶＤ法又はＭＢＥ法
により結晶成長を行わせた場合には、鏡面状態にある凹
溝内面には結晶膜が育成し、この凹溝内を埋めるが、粗
面加工を施して粗面状態となした凹溝以外の部分には膜
が育成されないか、育成されてもその膜は劣悪で簡単に
エツチングで除去できる。従って凹溝以外の部分に膜が
形成されても、リン酸などでエツチング処理することに
より凹溝部に形成した結晶膜に影響を及ぼすことなく除
去することができ、基板表面の凹溝部のみに結晶膜を形
成し得る。When crystal growth is performed by liquid phase epitaxial method, CVD method, or MBE method, a crystal film grows on the inner surface of the groove in a mirror-like state and fills the inside of the groove. In areas other than the grooves where the surface is roughened, no film is grown, or even if it is grown, the film is poor and can be easily removed by etching. Therefore, even if a film is formed on areas other than the grooves, it can be removed by etching with phosphoric acid without affecting the crystalline film formed on the grooves on the substrate surface. Can form a film.
また、真空蒸着法又はスパッタリング法により結晶膜を
形成させる場合には、鏡面状態にある凹溝内面に形成さ
れた膜は作成条件により真空蒸着又はスパッタリングの
みで結晶膜となるか、或いは真空蒸清又はスパッタリン
グ後の熱処理によって単結晶化されるが、粗面状態の部
分に生成した膜は熱処理の有無にかかわらず単結晶化さ
れず、熱処理の後剥離してしまう。従って、基板表面の
凹溝部のみに結晶膜が形成し得る。In addition, when forming a crystalline film by vacuum evaporation or sputtering, the film formed on the inner surface of the mirror-like groove may become a crystalline film only by vacuum evaporation or sputtering, or may become a crystalline film by vacuum evaporation or sputtering, depending on the production conditions. Alternatively, the film is made into a single crystal by heat treatment after sputtering, but the film formed on the rough surface is not made into a single crystal regardless of the presence or absence of the heat treatment and peels off after the heat treatment. Therefore, a crystal film can be formed only in the grooves on the substrate surface.
このようにして得られた凹溝部のみに結晶膜を形成し導
波層を設けた基板は、必要に応じて研磨により、凹溝部
に形成された結晶膜表面を整える。The thus obtained substrate on which a crystal film is formed and a waveguide layer is provided only in the grooves is polished as necessary to smooth the surface of the crystal film formed in the grooves.
そして、次いで、その上に被覆層を形成する。被覆層の
形成に関しては、先に第１の方法で述べたと同じである
。又、この際、粗面状態部分を鏡面状態とすれば被覆層
を結晶膜の上のみならず、基板全面に形成することがで
きる。Then, a covering layer is formed thereon. Regarding the formation of the covering layer, it is the same as described above in the first method. Further, at this time, if the rough surface portion is made into a mirror surface state, the coating layer can be formed not only on the crystal film but also on the entire surface of the substrate.
実施例１
１） ＧＧＧ単結晶ウェハを鏡面研磨した後、フォトレ
ジストを塗布し、露光及び現像処理により、導波路を形
成する部分に幅１０μｍのレジストパターンを形成した
。Example 1 1) After mirror polishing a GGG single crystal wafer, a photoresist was applied, and a resist pattern with a width of 10 μm was formed in a portion where a waveguide was to be formed by exposure and development.
２）その後、Ｒｆ （高周波）スパッタリング法により
Ｔｉ金属膜を形成し、次いでレジストパターン上のＴｉ
金属膜をレジストと共に除去する。即ち、幅ｌＯμｍの
導波路を形成させる部分は単結晶鏡面研磨面の状態とな
り、それ以外の部分はＴｉ金属膜により被覆されている
状態となる。2) After that, a Ti metal film is formed by Rf (radio frequency) sputtering method, and then a Ti metal film is formed on the resist pattern.
The metal film is removed together with the resist. That is, the portion where a waveguide with a width of 10 μm is to be formed has a mirror-polished single crystal surface, and the other portions are covered with a Ti metal film.
３）次いで、イオンビ・−ムエッチング装置にセットし
、導波路を形成させる部分が深さ３μｍとなるようにウ
ェハ全面をエツチングし、その後残ったＴｉ金属膜をフ
ッ酸：硝酸：水・１：ｌ：５０の水溶液で除去した。3) Next, the wafer was set in an ion beam etching system and the entire surface of the wafer was etched so that the portion where the waveguide was to be formed had a depth of 3 μm, and then the remaining Ti metal film was etched with hydrofluoric acid:nitric acid:water. It was removed with an aqueous solution of 1:50.
４）これにより、基板に凹型の導波路パターンを形成し
た。4) As a result, a concave waveguide pattern was formed on the substrate.
５）このウェハをＬＰＥ （液相エピタキシャル）成長
育成装置にセット、ＰｂＯ，Ｂｉ 、 Ｏ，、Ｂ、 Ｏ
，をフラックス成分としたＢｉ、 Ｙ、Ｆｅ、Ａ Ｑ
、 Ｏ，、＋ＰｂＯ＋Ｂｉ、Ｏ，＋Ｂ、Ｏ，の混合物融
液中で、（Ｂｉ、Ｙ）、（Ｆｅ、 Ａ［）、Ｏ８，単結
晶薄膜をウェハ上に育成した。育成条件は、基板回転数
１０ｏｒｐｍ、育成温度８４０℃、育成時間５分であっ
た。5) This wafer was set in an LPE (liquid phase epitaxial) growth device, and PbO, Bi, O,, B, O
, as flux components Bi, Y, Fe, A Q
, O, , +PbO+Bi, O, +B, O, single crystal thin films of (Bi, Y), (Fe, A[), O8, were grown on a wafer in a mixture melt of O, +PbO+Bi, O, +B, O,. The growth conditions were a substrate rotation speed of 10 orpm, a growth temperature of 840° C., and a growth time of 5 minutes.
次いで基板を回転数１１００ｏｒｐで５分間回転させて
フラックスを振り切り、徐冷の後、酢酸に１２時間浸漬
することにより余剰な付着物であるフラックス成分を除
去した。Next, the substrate was rotated at a rotational speed of 1100 rpm for 5 minutes to shake off the flux, and after slow cooling, it was immersed in acetic acid for 12 hours to remove excess flux components as deposits.
６）これにより、ウェハの全面に３〜５μｍの良質な（
Ｂｉ、Ｙ）、 （Ｆｅ、Ａ Ｑ ）、Ｏ，、単結晶薄膜
が成長した。6) This results in a high quality (3-5 μm) coating on the entire surface of the wafer.
Bi, Y), (Fe, A Q ), O, single crystal thin films were grown.
次いで、導波路以外の部分に成長した単結晶薄膜をｉ、
Ｏ，スラリー（粒度３、ｌおよび０．５μｍのものを順
次用いた）で研磨により除去した。この際、ウェハはス
ラリーではほとんど研磨されないため、導波路の形状は
当初の凹溝の形状になる。Next, the single crystal thin film grown on the part other than the waveguide was treated with i,
It was removed by polishing with O, slurry (particle sizes of 3, 1 and 0.5 μm were used sequentially). At this time, since the wafer is hardly polished with the slurry, the shape of the waveguide becomes the original groove shape.
７）この薄膜型導波路を９０℃リン酸で５分間化学エツ
チングした後、ＬＰＥ成長育成装置にセットし、ＰｂＱ
、 Ｂ、０．をフラックス成分としたＹ、 Ｆｅ、 Ｏ
，、＋ＰｂＯ＋Ｂ、０．の混合物融液中で、Ｙ、Ｆｅ、
Ｏ，、単結晶薄膜をウェハ上に育成し被覆層を形成した
。育成条件は、基板回転数１１００ｒｐ、育成温度９２
０℃、育成時間３０分であった。次いで基板を回転数１
１０００ｒｐで５分間回転させてフラックスを振り切り
、徐冷の後、酢酸にＩ２時間浸漬することにより余剰な
付着物であるフラックス成分を除去した。7) After chemically etching this thin film waveguide with phosphoric acid at 90°C for 5 minutes, it was set in an LPE growth apparatus and PbQ
, B, 0. Y, Fe, O with as flux components
,,+PbO+B,0. In the mixture melt of Y, Fe,
O, a single crystal thin film was grown on the wafer to form a coating layer. The growth conditions are: substrate rotation speed 1100 rp, growth temperature 92
The temperature was 0°C and the growth time was 30 minutes. Then rotate the board at 1
It was rotated at 1000 rpm for 5 minutes to shake off the flux, and after slow cooling, it was immersed in acetic acid for 12 hours to remove excess flux components as deposits.
８）これにより、ウェハの全面に６〜９μｍの良質なＹ
、 Ｆｅ、Ｏ３，単結晶薄膜が成長し、２層構造のアイ
ソレータ用単結晶薄膜を得た。8) This results in a high quality Y layer of 6 to 9 μm on the entire surface of the wafer.
, Fe, O3, single crystal thin film was grown to obtain a two-layer structure single crystal thin film for an isolator.
９）得た単結晶薄膜に、外部から５００Ｇの磁界を印加
し、Ｈｅ−Ｎｅレーザ（１，１５ｐｍ）を用いてアイソ
レーション比を測定したところ、２９ｄＢの値が得られ
た。9) When a magnetic field of 500 G was externally applied to the obtained single crystal thin film and the isolation ratio was measured using a He-Ne laser (1.15 pm), a value of 29 dB was obtained.
実施例２
１） ＧＧＧ単結晶ウェハを鏡面研磨した後、フォトレ
ジストを塗布し、露光及び現像処理により、導波路を形
成する部分に幅ＩＯμｍのレジストパターンを形成した
。Example 2 1) After mirror polishing a GGG single crystal wafer, a photoresist was applied, and a resist pattern with a width of IO μm was formed in a portion where a waveguide was to be formed by exposure and development.
２）その後、Ｒｆスパッタリング法によりＴｉ金属膜を
形成し、レジストパターン上のＴ１金属膜をレジストと
共に除去する。即ち、１０μｍの導波路を形成、させる
部分は単結晶鏡面研磨面の状態となり、それ以外の部分
はＴｉ金属膜により被覆されている状態となる。2) Thereafter, a Ti metal film is formed by Rf sputtering, and the T1 metal film on the resist pattern is removed together with the resist. That is, the portion where a 10 μm waveguide is to be formed becomes a mirror-polished single crystal surface, and the other portions are covered with a Ti metal film.
３）次いで、イオンビームエツチング装置にセットし、
導波路を形成させる部分が深さ５μｍとなるようにウェ
ハ全面をエツチングし、残ったＴｉ金属膜をフッ酸、：
硝酸：水・１：１：５０の水溶液で除去した。3) Next, set it in an ion beam etching device,
The entire surface of the wafer is etched so that the portion where the waveguide is to be formed has a depth of 5 μm, and the remaining Ti metal film is etched with hydrofluoric acid:
It was removed with an aqueous solution of nitric acid:water (1:1:50).
４）これにより、基板に凹型の導波路パターンを形成し
た。4) As a result, a concave waveguide pattern was formed on the substrate.
５）得たウェハを平行度が〈２μｍとなるように＃８０
０の耐水研磨紙でラッピングした後、超音波洗浄、乾燥
した。5) The obtained wafer is #80 so that the parallelism is <2 μm.
After wrapping with No. 0 waterproof abrasive paper, it was ultrasonically cleaned and dried.
６）このウェハをＬＰＥ成長育成装置にセット、ｐｂｏ
。6) Set this wafer in the LPE growth device, pbo
.
Ｂｌ、Ｏｍ、Ｂ＊（Ｌをフラックス成分としたＢｉ、
Ｙ、Ｆｅ４Ａ ＱＯ，、＋Ｂｉ、Ｏ，＋ＰｂＯ＋Ｂ、Ｏ
，の混合物融液中で、（Ｂｉ、Ｙ）。Bl, Om, B* (Bi with L as a flux component,
Y, Fe4A QO,,+Bi,O,+PbO+B,O
, (Bi, Y).
＜ＦＢ、 Ａ Ｑ ）ｓｏ＋ 、単結晶薄膜をウェハ上
に育成した。<FB, AQ) so+, a single crystal thin film was grown on a wafer.
育成条件は、基板回転数１１００ｒｐ、育成温度８４０
℃、育成時間５分であった。次いで基板を回転数１１０
０Ｏｒｐで５分間回転させてフラックスを振り切り、徐
冷の後、酢酸に１２時間浸漬することにより余剰な付着
物であるフラックス成分を除去した。The growth conditions were a substrate rotation speed of 1100 rpm and a growth temperature of 840 rpm.
℃, and the growth time was 5 minutes. Then the board was rotated at 110 rpm.
It was rotated at 0 Orp for 5 minutes to shake off the flux, and after slow cooling, it was immersed in acetic acid for 12 hours to remove excess deposits of flux components.
７）導波路部分には、５〜６μｍの良質な（Ｂｉ、Ｙ）
。7) In the waveguide part, 5 to 6 μm high quality (Bi, Y)
.
（Ｆｅ、Ａ Ｑ ）、Ｏ，、単結晶薄膜が成長したが、
ラップ研磨面には何等成長せず、ラップ研磨面のままで
あった。(Fe, A Q ), O,, a single crystal thin film was grown,
No growth occurred on the lapped surface, and the lapped surface remained as it was.
８）次いで、０．５μｍのアルミナスラリーで研磨した
ところ、良好な形状を有する（Ｂｉ、Ｙ）ａ（Ｆｅ、Ａ
Ｑ ）。8) Next, when polished with 0.5 μm alumina slurry, (Bi, Y) a (Fe, A
Q).
０１．単結晶薄膜型導波路を得た。01. A single crystal thin film waveguide was obtained.
９）この薄膜型導波路を９０℃リン酸で５分間化学エツ
チングした後、ＬＰＥ成長育成装置にセットし、ＰｂＯ
，Ｂ、０．をフラックス成分としたＹ、 Ｆｅ、 Ｏ，
、＋ＰｂＯ＋Ｂ、 Ｏ，の混合物融液中で、Ｙ、 Ｆｅ
、 Ｏ，、単結晶薄膜をウェハ上に育成し被覆層を形成
した。育成条件は基板回転数１１００ｒｐ、育成温度９
２０℃、育成時間３０分であった。次いで基板を回転数
１１０００ｒｐで５分間回転させてフラックスを振り切
り、徐冷の後、酢酸に１２時間浸漬することにより余剰
な付着物であるフラックス成分を除去した。9) After chemically etching this thin film waveguide with phosphoric acid at 90°C for 5 minutes, it was set in an LPE growth apparatus and PbO
,B,0. Y, Fe, O, with as flux components
, +PbO+B, O, in a mixture melt of Y, Fe
, O, A single crystal thin film was grown on the wafer to form a coating layer. Growth conditions are substrate rotation speed 1100 rp, growth temperature 9
The temperature was 20°C and the growth time was 30 minutes. Next, the substrate was rotated at a rotational speed of 11,000 rpm for 5 minutes to shake off the flux, and after slow cooling, it was immersed in acetic acid for 12 hours to remove excess deposits of flux components.
１０）これにより、導波層単結晶上に７〜８μｍの良質
なＹ、Ｆｅ、Ｏ，、単結晶薄膜が成長し、２層構造のア
イソレータ用単結晶薄膜を得た。10) As a result, a high-quality Y, Fe, O, single crystal thin film with a thickness of 7 to 8 μm was grown on the waveguide single crystal, and a two-layer structure single crystal thin film for an isolator was obtained.
１１）得た単結晶薄膜に、外部から５００Ｇの磁界を印
加し、Ｈｅ−Ｎｅレーザ（１、１５μｍ）を用いてアイ
ソレーション比を測定したところ、２９ｄＢの値が得ら
れた。11) A magnetic field of 500 G was externally applied to the obtained single crystal thin film, and the isolation ratio was measured using a He-Ne laser (1.15 μm), and a value of 29 dB was obtained.
（発明の効果）
本発明方法によると、結晶基板、該基板上に形成された
磁気光学材料からなる導波層及び導波層上に形成された
被覆層とからなる薄膜導波型光アイソレータを精度良く
かつ能率よく量産できる。(Effects of the Invention) According to the method of the present invention, a thin film waveguide optical isolator consisting of a crystal substrate, a waveguide layer made of a magneto-optic material formed on the substrate, and a coating layer formed on the waveguide layer can be manufactured. Can be mass-produced with high precision and efficiency.
また本発明は、基板上に育成させた結晶膜にエツチング
を施して不用部分を除去し整形する工程を必要としない
ので、エツチング時に生じやすい失敗による結晶膜の無
駄を無くすることができる利点がある。そして、たとえ
基板表面に凹溝を設ける工程で失敗しても、基板の損失
のみで済むため有利である。従って、本方法によれば、
低コストで上記構造の薄膜導波型光アイソレータを製造
することができる。Furthermore, the present invention does not require the process of etching the crystal film grown on the substrate to remove unnecessary parts and shaping it, so it has the advantage of eliminating wastage of the crystal film due to failures that tend to occur during etching. be. Further, even if a failure occurs in the process of forming grooves on the surface of the substrate, it is advantageous because only the loss of the substrate will occur. Therefore, according to this method,
A thin film waveguide type optical isolator having the above structure can be manufactured at low cost.
第１〜４図は、本発明方法の製造過程の一例を示した薄
膜導波型光アイソレータの断面図である。
第１図は凹溝を形成した基板の断面図、第２図は該基板
に単結晶膜を育成させた断面図、第３図は凹溝に単結晶
膜を形成させたチャンネル型光導波路の断面図、第４図
は本発明で得られた薄膜導波型光アイソレータの断面図
である。
■・・・基板 ２・・・凹溝 ３・・・結晶膜４・
・・導波層 ５・・・被覆層1 to 4 are cross-sectional views of a thin film waveguide type optical isolator showing an example of the manufacturing process of the method of the present invention. Figure 1 is a cross-sectional view of a substrate with grooves formed therein, Figure 2 is a cross-sectional view of a single crystal film grown on the substrate, and Figure 3 is a cross-sectional view of a channel type optical waveguide with a single crystal film formed in grooves. 4 is a cross-sectional view of a thin film waveguide type optical isolator obtained by the present invention. ■...Substrate 2...Concave groove 3...Crystal film 4...
... Waveguide layer 5 ... Covering layer
Claims (1)
料の結晶膜を育成させて導波層を形成し、次いで少なく
とも導波層上に被覆層を形成することを特徴とする薄膜
導波型光アイソレータの製造方法。 ２、基板表面に凹溝を設け、この基板表面全面に磁気光
学材料の結晶膜を育成させ、次いで凹溝部以外に育成さ
れた結晶膜を除去し、凹溝のみに結晶膜を存在させて導
波層を形成する請求項第１項記載の薄膜導波型光アイソ
レータの製造方法。 ３、基板表面に凹溝を設け、且つこの凹溝部以外の表面
を粗面状態となし、次いで基板表面全面に磁気光学材料
の結晶膜育成操作を施すことにより、凹溝のみに結晶膜
を育成させて導波層を形成する請求項第１項記載の薄膜
導波型光アイソレータの製造方法。[Claims] 1. A groove is provided on the surface of the substrate, a crystalline film of a magneto-optical material is grown only in the groove to form a waveguide layer, and then a coating layer is formed at least on the waveguide layer. A method for manufacturing a thin film waveguide optical isolator, characterized by: 2. A groove is provided on the surface of the substrate, a crystal film of the magneto-optical material is grown on the entire surface of the substrate, and then the crystal film grown in areas other than the groove is removed, and the crystal film is left only in the groove to conduct the conduction. 2. The method for manufacturing a thin film waveguide type optical isolator according to claim 1, wherein a wave layer is formed. 3. A groove is provided on the surface of the substrate, the surface other than the groove is roughened, and then a crystal film of the magneto-optical material is grown on the entire surface of the substrate, thereby growing a crystal film only in the groove. 2. The method of manufacturing a thin film waveguide type optical isolator according to claim 1, wherein the waveguide layer is formed by forming a waveguide layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7193589A JPH02251912A (en) | 1989-03-27 | 1989-03-27 | Production of thin-film waveguide type optical isolator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7193589A JPH02251912A (en) | 1989-03-27 | 1989-03-27 | Production of thin-film waveguide type optical isolator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02251912A true JPH02251912A (en) | 1990-10-09 |
Family
ID=13474866
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7193589A Pending JPH02251912A (en) | 1989-03-27 | 1989-03-27 | Production of thin-film waveguide type optical isolator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02251912A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002077715A3 (en) * | 2001-03-21 | 2003-05-22 | Intel Corp | Method of fabrication to sharpen corners of waveguide y-branches in integrated optical components |
| WO2002093205A3 (en) * | 2001-03-21 | 2003-10-09 | Intel Corp | Fabrication of optical waveguides for reduction of minimum waveguide spacing |
-
1989
- 1989-03-27 JP JP7193589A patent/JPH02251912A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002077715A3 (en) * | 2001-03-21 | 2003-05-22 | Intel Corp | Method of fabrication to sharpen corners of waveguide y-branches in integrated optical components |
| WO2002093205A3 (en) * | 2001-03-21 | 2003-10-09 | Intel Corp | Fabrication of optical waveguides for reduction of minimum waveguide spacing |
| US6730988B2 (en) | 2001-03-21 | 2004-05-04 | Intel Corporation | Method of fabrication to sharpen corners of Y-branches in integrated optical components and other micro-devices |
| US6818559B2 (en) | 2001-03-21 | 2004-11-16 | Intel Corporation | Method of fabrication to sharpen corners of Y-branches in integrated optical components and other micro-devices |
| US6864114B2 (en) | 2001-03-21 | 2005-03-08 | Intel Corporation | Fabrication of optical waveguides for reduction of minimum waveguide spacing |
| US7039288B2 (en) | 2001-03-21 | 2006-05-02 | Intel Corporation | Fabrication of optical waveguides for reduction of minimum waveguide spacing |
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