JPH11231152A - Waveguide and its production - Google Patents
Waveguide and its productionInfo
- Publication number
- JPH11231152A JPH11231152A JP10029851A JP2985198A JPH11231152A JP H11231152 A JPH11231152 A JP H11231152A JP 10029851 A JP10029851 A JP 10029851A JP 2985198 A JP2985198 A JP 2985198A JP H11231152 A JPH11231152 A JP H11231152A
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- JP
- Japan
- Prior art keywords
- layer
- core
- fluorine
- concentration
- waveguide
- Prior art date
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】高比屈折率差導波路およびそ
の製造方法に関する。[0001] 1. Field of the Invention [0002] The present invention relates to a high relative index difference waveguide and a method of manufacturing the same.
【０００２】[0002]
【従来の技術】ＳｉＯ2 系導波路を高比屈折率差（以
下、高△と記す。）型として、光デバイスの小型化、多
機能化、低コスト化することが求められている。 2. Description of the Related Art It is required to reduce the size, multifunctionality, and cost of an optical device by using a SiO 2 -based waveguide of a high relative refractive index difference (hereinafter referred to as “high △”) type.
【０００３】従来の研究開発は、ＣＶＤ技術などを利用
してコアの比屈折率を高め、且つ、ＯＨ基などによる吸
収損失を低減することを現実しようとした。[0003] Conventional research and development have attempted to increase the relative refractive index of the core by using a CVD technique or the like and to reduce absorption loss due to OH groups and the like.
【０００４】コアの屈折率を高めるために、ＳｉＯｘＮ
ｙＨｚ（以下、ＳｉＯＮＨと記す。）を使用すること、
あるいは屈折率向上成分（ＴｉＯ2 、ＧｅＯ2 など）を
添加することが検討されたので以下に説明する。In order to increase the refractive index of the core, SiOxN
yHz (hereinafter referred to as SiONH);
Alternatively, addition of a refractive index improving component (TiO 2 , GeO 2, etc.) has been considered, and will be described below.
【０００５】図１１は、ＳｉＯＮＨコアを有する導波路
の概観斜視図である。FIG. 11 is a schematic perspective view of a waveguide having an SiONH core.
【０００６】図１１に示す導波路は、基板１上に低屈折
率の下部クラッド層（ＳｉＯ2 ）２を形成し、その下部
クラッド層２上に略矩形状断面形状の高屈折率コア層
（ＳｉＯＮＨ）３を形成し、下部クラッド層２及びコア
層３を上部クラッド層（ＳｉＯ2 ）４で覆った構造を有
している。In the waveguide shown in FIG. 11, a lower cladding layer (SiO 2 ) 2 having a low refractive index is formed on a substrate 1, and a high refractive index core layer having a substantially rectangular cross section is formed on the lower cladding layer 2. (SiONH) 3 and the lower clad layer 2 and the core layer 3 are covered with an upper clad layer (SiO 2 ) 4.
【０００７】図１２は、ＳｉＯＮＨ膜中の窒素含有率−
屈折率関係図である。但し、標準試料はＳｉ3 Ｎ4 （Ｓ
ｉ：４３．２アトミック％、Ｎ：５６．７３アトミック
％）。（窒素含有率：アトミック％、屈折率：波長０．
６３μｍ、比屈折率差△：％） 図１１に示した高△導波路は、コア層３にＳｉＯＮＨを
用いるので、図１２に示すように窒素Ｎの含有量を制御
することによって屈折率を非常に高くすることができる
という利点がある。（図１２参照。） 図１３は、屈折率制御添加物量−屈折率関係図である。FIG. 12 shows the nitrogen content in the SiONH film.
It is a refractive index relationship diagram. However, the standard sample is Si 3 N 4 (S
i: 43.2 atomic%, N: 56.73 atomic%). (Nitrogen content: atomic%, refractive index: wavelength 0.1.
63 μm, relative refractive index difference Δ:%) Since the high- △ waveguide shown in FIG. 11 uses SiONH for the core layer 3, as shown in FIG. There is an advantage that it can be higher. (See FIG. 12.) FIG. 13 is a graph showing the relationship between the amount of the refractive index control additive and the refractive index.
【０００８】因みに、ＳｉＯ2 にＴｉＯ2 、Ａｌ
2 Ｏ3 、ＧｅＯ2 あるいはＰ2 Ｏ5 等の屈折率制御用ド
ーパントを添加した場合には、図１３に示すようにＳｉ
ＯＮＨの場合（図１２参照。）より屈折率を高くするこ
とができない。[0008] By the way, TiO 2, Al on SiO 2
When a refractive index controlling dopant such as 2 O 3 , GeO 2 or P 2 O 5 is added, as shown in FIG.
The refractive index cannot be made higher than in the case of ONH (see FIG. 12).
【０００９】図１４は、プラズマＣＶＤ装置の概略図で
ある。FIG. 14 is a schematic view of a plasma CVD apparatus.
【００１０】以下、図１１に示されるＳｉＯＮＨコアを
有する導波路を、図１４に示されているプラズマＣＶＤ
装置を用いて製造する方法を説明する。Hereinafter, the waveguide having the SiONH core shown in FIG. 11 will be referred to as a plasma CVD shown in FIG.
A method of manufacturing using the apparatus will be described.
【００１１】真空排気装置５によって真空排気される反
応容器６内に、上部電極７と下部電極８とを対向配置さ
せ、両電極７，８間に高周波電源９により高周波電圧を
印加する。下部電極８上に基板１を設置し、下部電極８
に設けられたヒータ１１に直流電源１２から電圧を印加
して１５０℃から４５０℃の範囲に加熱する。An upper electrode 7 and a lower electrode 8 are arranged opposite to each other in a reaction vessel 6 which is evacuated by an evacuation device 5, and a high frequency voltage is applied between the electrodes 7 and 8 by a high frequency power supply 9. The substrate 1 is placed on the lower electrode 8 and the lower electrode 8
A voltage is applied from a DC power supply 12 to a heater 11 provided in the heater 11 to heat the heater 11 in a range of 150 ° C. to 450 ° C.
【００１２】ついで両電極７，８間にＡｒガス（矢印１
３方向）を流して両電極７，８間にプラズマ１４を発生
させる。このような状態でガラス原料ガスを矢印１５−
１方向から矢印１５−２方向に送ってプラズマ１４中に
流す。また矢印１３方向からＮ2 ガスをプラズマ１４中
に流す。基板１上に下部ＳｉＯ2 クラッド２（図１０参
照）を形成する場合には、矢印１５−１方向からガラス
原料ガスとしてＳｉＨ4 ガス及びＯ2 ガスを流す。Next, Ar gas (arrow 1) is applied between the electrodes 7 and 8.
(In three directions) to generate a plasma 14 between the electrodes 7 and 8. In this state, the glass raw material gas is supplied by the arrow 15-.
It is sent in the direction of arrow 15-2 from one direction and flows into the plasma 14. An N 2 gas is flowed into the plasma 14 from the direction of arrow 13. When the lower SiO 2 cladding 2 (see FIG. 10) is formed on the substrate 1, SiH 4 gas and O 2 gas are flowed as glass raw material gases from the direction of arrow 15-1.
【００１３】基板１上に下部ＳｉＯ2 クラッド２を形成
した後にＳｉＯＮＨコア３を形成する場合には、矢印１
５−１方向からガラス原料ガスとしてＳｉＨ4 ガス、Ｎ
Ｈ3ガス及びＯ2 ガスを流す。When the SiONH core 3 is formed after the lower SiO 2 cladding 2 is formed on the substrate 1, the arrow 1
From the 5-1 direction, SiH 4 gas, N
H 3 gas and O 2 gas are flowed.
【００１４】ＳｉＯＮＨコア３をフォトリソグラフィ及
びドライエッチングプロセスにより、略矩形断面形状に
パターニングする。その後、パターニングしたＳｉＯＮ
Ｈコア３の表面を上部ＳｉＯ2 クラッド層４で覆うため
に下部ＳｉＯ2 クラッド層２と同様に、矢印１５−１方
向よりガラス原料ガスとしてＳｉＨ4 ガス及びＯ2 ガス
を流す。The SiONH core 3 is patterned into a substantially rectangular cross section by photolithography and dry etching processes. Then, patterned SiON
In order to cover the surface of the H core 3 with the upper SiO 2 cladding layer 4, similarly to the lower SiO 2 cladding layer 2, SiH 4 gas and O 2 gas are flowed from the direction of arrow 15-1 as glass source gases.
【００１５】次に、図１１に示したＳｉＯＮＨコアを有
する高△導波路の損失波長特性について述べる。Next, the loss wavelength characteristic of the high- △ waveguide having the SiONH core shown in FIG. 11 will be described.
【００１６】図１５は、吸収損失−波長特性図である。
（ａ）は焼処理前、（ｂ）は熱処理後を示す。但し、波
長：μｍ、損失：ｄＢである。FIG. 15 is an absorption loss-wavelength characteristic diagram.
(A) shows the state before the baking treatment, and (b) shows the state after the heat treatment. However, the wavelength is μm and the loss is dB.
【００１７】図１５（ａ）は、コアとクラッド層２，４
との比屈折率差△が約２％、コア３のサイズが幅５μ
ｍ、厚さ２．５μｍの導波路の損失波長特性の測定結果
である。この損失は、高△導波路の伝搬損失（吸収損失
及び散乱損失）、高△導波路とシングルモードファイバ
との接続損失（導波路の入力側と出力側の２か所分）を
含んでいる。波長０．６μｍから波長１．３５μｍにわ
たって非常に低損失であった。FIG. 15A shows the core and cladding layers 2 and 4.
The relative refractive index difference と is about 2%, and the size of the core 3 is 5 μm in width.
9 shows measurement results of loss wavelength characteristics of a waveguide having a thickness of 2.5 μm and a thickness of 2.5 μm. This loss includes the propagation loss (absorption loss and scattering loss) of the high- △ waveguide, and the connection loss between the high- △ waveguide and the single-mode fiber (two portions on the input side and the output side of the waveguide). . The loss was very low from a wavelength of 0.6 μm to a wavelength of 1.35 μm.
【００１８】しかし、波長１．３９μｍにＯＨ基による
吸収損失と波長１．５μｍ付近にＳｉ−Ｈ基（或いはＮ
−Ｈ基）による吸収損失があった。However, the absorption loss due to the OH group at a wavelength of 1.39 μm and the Si—H group (or N
-H group).
【００１９】そこで、このＳｉＯＮＨコアを有する高△
導波路を１０００℃で熱処理した結果、図１５（ｂ）に
示すように、波長１．３９μｍにＯＨ基による吸収損失
がある程度低減された。Therefore, the high-temperature steel having this SiONH core is used.
As a result of heat treatment of the waveguide at 1000 ° C., as shown in FIG. 15B, the absorption loss due to the OH group was reduced to some extent at a wavelength of 1.39 μm.
【００２０】さらに、このＳｉＯＮＨコアを有する高△
導波路を１２００℃で熱処理した結果、波長１．３９μ
ｍ付近のＯＨ基による吸収損失はからり減少したが、完
全になくすことはできなかった。これは、ＳｉＯＮＨコ
ア中には、ＳｉＨ4 とＯ2 とＮＨ3 、Ｎ2 との反応に際
して不可避的にＳｉ−Ｈ基、Ｎ−Ｈ基が含まれているた
めと考えられる。Further, the high-temperature steel having the SiONH core
As a result of heat treatment of the waveguide at 1200 ° C., the wavelength was 1.39 μm.
The absorption loss due to the OH group near m was diminished, but could not be completely eliminated. This is in SiONH core, presumably because inevitably SiH group, the NH group is included in the reaction of SiH 4 and O 2 and NH 3, N 2.
【００２１】以上のように、ＳｉＯＮＨコアを有する高
△導波路および屈折率向上成分添加高△導波路には多く
の問題がある。As described above, there are many problems in the high-ＮＨ waveguide having the SiONH core and the high- △ waveguide with the added refractive index improving component.
【００２２】（１）ＳｉＯＮＨコアには、波長１．３９
μｍに吸収ピークを有するＯＨ基による吸収損失と波長
１．５μｍに吸収ピークを有するＮ−Ｈ基（或いはＳｉ
−Ｈ基）による吸収損失が含まれている。そのため、波
長１．３９μｍから波長１．６μｍの範囲の通信用波長
帯での損失が大きい。この吸収損失は高温で熱処理して
も充分に低減することが難しい。(1) The SiONH core has a wavelength of 1.39.
absorption loss due to an OH group having an absorption peak at μm and an NH group (or Si) having an absorption peak at a wavelength of 1.5 μm.
-H group). Therefore, the loss is large in the communication wavelength band in the wavelength range of 1.39 μm to 1.6 μm. It is difficult to sufficiently reduce this absorption loss even by heat treatment at a high temperature.
【００２３】（２）下部ＳｉＯ2 クラッド層及び上部Ｓ
ｉＯ2 クラッド層内にもＯＨ基が含まれており、低吸収
損失化を困難にする。上記のように、高温で熱処理する
と、クラッド層からコアへ上記ＯＨ基が拡散してコア中
のＯＨ基が増大して吸収損失を増大させる問題も発生す
る。(2) Lower SiO 2 cladding layer and upper S
OH groups are also contained in the iO 2 cladding layer, which makes it difficult to reduce absorption loss. As described above, when the heat treatment is performed at a high temperature, the OH groups diffuse from the cladding layer to the core, and the OH groups in the core increase, thereby causing a problem of increasing absorption loss.
【００２４】（３）また、コアに屈折率向上成分（Ｔｉ
Ｏ2 、Ａｌ2 Ｏ3 、ＧｅＯ2 、Ｐ2 Ｏ5 など）を添加す
る技術を採用しようとすると、添加成分の不均一分布に
よる吸収損失の増大、添加成分自身のよる吸収損失の増
大などの問題から超低吸収損失導波路の実現は困難であ
る。(3) A refractive index improving component (Ti) is added to the core.
O 2 , Al 2 O 3 , GeO 2 , P 2 O 5, etc.), the absorption loss due to the non-uniform distribution of the added component, the absorption loss due to the added component itself, etc. Due to problems, it is difficult to realize an ultra-low absorption loss waveguide.
【００２５】[0025]
【発明が解決しようとする課題】低損失特性を有し、長
期的損失増大要因が除かれた高比屈折率差（高△）導波
路およびその製造方法を可能とする。SUMMARY OF THE INVENTION It is possible to provide a high relative refractive index difference (high △) waveguide having low loss characteristics and eliminating a long-term loss increase factor, and a method of manufacturing the same.
【００２６】[0026]
【課題を解決するための手段】本発明の導波路は、フッ
素をより低濃度に添加されたＳｉＯ2 系ガラスから成る
低濃度フッ素添加ＳｉＯ2 コアと、上記コアを埋込み、
且つ、フッ素をより高濃度に添加されたＳｉＯ2 系ガラ
スから成る高濃度フッ素添加ＳｉＯ2 クラッド層とを具
備することを特徴とする。According to the present invention, there is provided a waveguide in which a low-concentration fluorine-added SiO 2 core made of SiO 2 glass to which fluorine is added at a lower concentration is embedded, and the core is embedded therein.
And a high-concentration fluorine-added SiO 2 clad layer made of SiO 2 glass to which fluorine is added at a higher concentration.
【００２７】本発明の導波路は、基板上に形成された導
波路であって、高濃度フッ素添加ＳｉＯ2 層の中に、略
矩形状の断面を有するコアが埋め込まれた構造を有し、
且つ、上記コアが低濃度フッ素添加ＳｉＯ2 から成る導
波路である。The waveguide of the present invention is a waveguide formed on a substrate, and has a structure in which a core having a substantially rectangular cross section is embedded in a high-concentration fluorine-added SiO 2 layer,
Further, the core is a waveguide made of low-concentration fluorine-added SiO 2 .
【００２８】上記基板としては、石英ガラス（Ｓｉ
Ｏ2 ）基板、Ｓｉ基板の他、多成分系ガラス基板、セラ
ミック基板、Ｉｎ−Ｐ基板、Ｇａ−Ａｓ基板などが挙げ
られる。As the substrate, quartz glass (Si
In addition to the O 2 ) substrate and the Si substrate, a multi-component glass substrate, a ceramic substrate, an In-P substrate, a Ga-As substrate, and the like can be given.
【００２９】[0029]
【発明の実施の形態】本発明の導波路であって、具体化
された一群のものは、基板上に形成された高濃度フッ素
添加ＳｉＯ2 層の中に略矩形状の断面を有するコアが埋
め込まれた構造を有し、且つ、上記コアが低濃度フッ素
添加ＳｉＯ2 から成る導波路において、上記高濃度フッ
素添加ＳｉＯ2 層が、上記コアの下面に接する下部クラ
ッド層と、上記コアの側面および上面に接する上部クラ
ッド層とで構成された導波路である。BEST MODE FOR CARRYING OUT THE INVENTION A group of embodied waveguides according to the present invention comprises a core having a substantially rectangular cross section in a high-concentration fluorine-doped SiO 2 layer formed on a substrate. A waveguide having an embedded structure, wherein the core is made of low-concentration fluorine-added SiO 2, wherein the high-concentration fluorine-added SiO 2 layer is in contact with a lower surface of the core; And an upper clad layer in contact with the upper surface.
【００３０】本発明の導波路であって、具体化された一
群のものは、基板上に形成された高濃度フッ素添加Ｓｉ
Ｏ2 層の中に略矩形状の断面を有するコアが埋め込まれ
た構造を有し、且つ、上記コアが低濃度フッ素添加Ｓｉ
Ｏ2 から成り、さらに上記高濃度フッ素添加ＳｉＯ2 層
が、上記コアの下面に接する下部クラッド層と、上記コ
アの側面および上面に接する上部クラッド層とで構成さ
れる導波路において、上記上部クラッド層中のフッ素濃
度が厚さ方向の勾配を有するように分布している導波路
である。A group of embodied waveguides of the present invention is a highly doped fluorinated Si formed on a substrate.
It has a structure in which a core having a substantially rectangular cross section is embedded in an O 2 layer, and the core is made of low-concentration fluorine-added Si.
O 2 , wherein the high-concentration fluorine-added SiO 2 layer further comprises a lower clad layer in contact with the lower surface of the core, and an upper clad layer in contact with the side and upper surfaces of the core. This is a waveguide in which the fluorine concentration in the layer is distributed so as to have a gradient in the thickness direction.
【００３１】本発明の導波路であって、具体化された一
群のものは、基板上に形成された高濃度フッ素添加Ｓｉ
Ｏ2 層の中に略矩形状の断面を有するコアが埋め込まれ
た構造を有し、且つ、上記コアが低濃度フッ素添加Ｓｉ
Ｏ2 から成り、さらに上記高濃度フッ素添加ＳｉＯ2 層
が、上記コアの下面に接する下部クラッド層と、上記コ
アの側面および上面に接する上部クラッド層とで構成さ
れる導波路において、上記上部クラッド層が、ホウ素
（Ｂ）成分かリン（Ｐ）成分、あるいはその両成分を共
添加されている導波路である。A group of embodied waveguides of the present invention is a heavily doped Si doped on a substrate.
It has a structure in which a core having a substantially rectangular cross section is embedded in an O 2 layer, and the core is made of low-concentration fluorine-added Si.
O 2 , wherein the high-concentration fluorine-added SiO 2 layer further comprises a lower clad layer in contact with the lower surface of the core, and an upper clad layer in contact with the side and upper surfaces of the core. The layer is a waveguide to which a boron (B) component, a phosphorus (P) component, or both components are co-doped.
【００３２】本発明の導波路であって、具体化された一
群のものは、上記導波路が、導波路の形成過程における
コア層形成後、またはコア層の略矩形断面パターニング
後または高濃度フッ素添加ＳｉＯ2 層へのコア埋込後の
何れかの段階において、酸素雰囲気中且つ１０００℃〜
１２５０℃の温度範囲で少なくとも１回熱処理されてい
る導波路である。In a group of embodied waveguides according to the present invention, the waveguide may be formed after a core layer is formed in the process of forming the waveguide, after a substantially rectangular cross-section patterning of the core layer, or when a high concentration fluorine is used. At any stage after embedding the core in the added SiO 2 layer, in an oxygen atmosphere and at 1000 ° C.
This is a waveguide that has been heat-treated at least once in a temperature range of 1250 ° C.
【００３３】本発明の導波路の製造方法であって、具体
化された一群のものは、基板上に、高濃度フッ素添加Ｓ
ｉＯ2 層の中に、略矩形状の断面を有する低濃度フッ素
添加ＳｉＯ2 コアが埋込まれた構造を構成する導波路の
製造方法において、上記高濃度フッ素添加ＳｉＯ2 およ
び低濃度フッ素添加ＳｉＯ2 を、必須の反応成分として
ケイ素（Ｓｉ）原料であるシランあるいは有機オキシシ
ランとフッ素（Ｆ）原料であるフッ素化炭化水素と酸化
性ガスとを反応させるプラズマＣＶＤ法を用いて製造す
る導波路の製造方法である。A method of manufacturing a waveguide according to the present invention, which is a group of embodied materials, comprises a step of forming a high-concentration fluorine-doped S
In the method of manufacturing a waveguide having a structure in which a low-concentration fluorine-added SiO 2 core having a substantially rectangular cross section is embedded in an iO 2 layer, the above-described high-concentration fluorine-added SiO 2 and low-concentration fluorine-added SiO 2 2 is a waveguide manufactured by using a plasma CVD method in which silane or organic oxysilane as a raw material of silicon (Si), fluorinated hydrocarbon as a raw material of fluorine (F) and an oxidizing gas are reacted as essential reaction components. It is a manufacturing method.
【００３４】本発明の導波路の製造方法であって、具体
化された一群のものは、基板上に、高濃度フッ素添加Ｓ
ｉＯ2 層の中に、略矩形状の断面を有する低濃度フッ素
添加ＳｉＯ2 コアが埋込まれた構造を構成する導波路の
製造方法において、上記基板としてＳｉＯ2 基板を用
い、基板上に高濃度フッ素添加ＳｉＯ2 下部クラッド層
を形成し、次いで得られる下部クラッド層上に低濃度フ
ッ素添加ＳｉＯ2 層を形成し、さらに上記低濃度フッ素
添加ＳｉＯ2 を加工して略矩形状断面を有するコアと
し、さらに次いで上記低濃度フッ素添加ＳｉＯ2 コアの
両側面と上面とに接する高濃度フッ素添加ＳｉＯ2 上部
クラッド層を形成する導波路の製造方法である。A method of manufacturing a waveguide according to the present invention, which is embodied in a group, comprises a step of forming a high-concentration fluorine-doped S
In a method of manufacturing a waveguide having a structure in which a low-concentration fluorine-added SiO 2 core having a substantially rectangular cross section is embedded in an iO 2 layer, an SiO 2 substrate is used as the substrate, and a high core having a density fluoridation to form a SiO 2 lower clad layer, then a low concentration fluorine-added SiO 2 layer is formed on the lower clad layer obtained, substantially rectangular cross-section further processed the low concentration fluorine-added SiO 2 And then forming a high-concentration fluorine-added SiO 2 upper clad layer in contact with both side surfaces and the upper surface of the low-concentration fluorine-added SiO 2 core.
【００３５】本発明の導波路の製造方法であって、具体
化された一群のものは、基板上に、高濃度フッ素添加Ｓ
ｉＯ2 層の中に、略矩形状の断面を有する低濃度フッ素
添加ＳｉＯ2 コアが埋込まれた構造を構成する導波路の
製造方法において、上記基板としてＳｉＯ2 基板を用
い、基板上に高濃度フッ素添加ＳｉＯ2 下部クラッド層
を形成し、次いで得られる下部クラッド層上に低濃度フ
ッ素添加ＳｉＯ2 層を形成し、さらに上記低濃度フッ素
添加ＳｉＯ2 を加工して略矩形状断面を有するコアと
し、さらに次いで上記低濃度フッ素添加ＳｉＯ2 コアの
両側面と上面とに接する高濃度フッ素添加ＳｉＯ2 上部
クラッド層を形成する導波路の製造方法である。A method of manufacturing a waveguide according to the present invention, which is a group of embodied materials, comprises a step of forming a high-concentration fluorine-doped S
In a method of manufacturing a waveguide having a structure in which a low-concentration fluorine-added SiO 2 core having a substantially rectangular cross section is embedded in an iO 2 layer, an SiO 2 substrate is used as the substrate, and a high core having a density fluoridation to form a SiO 2 lower clad layer, then a low concentration fluorine-added SiO 2 layer is formed on the lower clad layer obtained, substantially rectangular cross-section further processed the low concentration fluorine-added SiO 2 And then forming a high-concentration fluorine-added SiO 2 upper clad layer in contact with both side surfaces and the upper surface of the low-concentration fluorine-added SiO 2 core.
【００３６】本発明の導波路の製造方法であって、具体
化された一群のものは、基板上に、高濃度フッ素添加Ｓ
ｉＯ2 層の中に、略矩形状の断面を有する低濃度フッ素
添加ＳｉＯ2 コアが埋込まれた構造を構成する導波路の
製造方法において、上記基板としてＳｉＯ2 基板を用
い、基板上に高濃度フッ素添加ＳｉＯ2 下部クラッド層
を形成し、次いで得られる下部クラッド層上に低濃度フ
ッ素添加ＳｉＯ2 層を形成し、さらに上記低濃度フッ素
添加ＳｉＯ2 を加工して略矩形状断面を有するコアと
し、さらに次いで上記低濃度フッ素添加ＳｉＯ2 コアの
両側面と上面とに接する高濃度フッ素添加ＳｉＯ2 上部
クラッド層を形成して得られる構造物を高温熱処理し
て、上記高濃度フッ素添加ＳｉＯ2 上部クラッド層中の
フッ素が表面側で低濃度で深部である濃度勾配を有する
ように分布させる導波路の製造方法である。The method of manufacturing a waveguide according to the present invention, which is embodied as a group, comprises a step of forming a high-concentration fluorine-doped S
In a method of manufacturing a waveguide having a structure in which a low-concentration fluorine-added SiO 2 core having a substantially rectangular cross section is embedded in an iO 2 layer, an SiO 2 substrate is used as the substrate, and a high core having a density fluoridation to form a SiO 2 lower clad layer, then a low concentration fluorine-added SiO 2 layer is formed on the lower clad layer obtained, substantially rectangular cross-section further processed the low concentration fluorine-added SiO 2 and then, further followed by high temperature heat treatment the low-concentration fluorine-doped contact with the both side surfaces and the upper surface of the SiO 2 core high concentration fluoridated structure obtained by forming a SiO 2 upper clad layer, the high concentration fluorine-added SiO 2 This is a method for producing a waveguide in which fluorine in the upper cladding layer is distributed so as to have a low concentration and a deep concentration gradient on the surface side.
【００３７】本発明の導波路の製造方法であって、具体
化された一群のものは、基板上に、高濃度フッ素添加Ｓ
ｉＯ2 層の中に、略矩形状の断面を有する低濃度フッ素
添加ＳｉＯ2 コアが埋込まれた構造を構成する導波路の
製造方法において、上記基板としてＳｉ基板を用い、上
記Ｓｉ基板上にＳｉＯ2 バッファ層を形成し、得られる
ＳｉＯ2 バッファ層上に高濃度フッ素添加ＳｉＯ2 下部
クラッド層を形成し、次いで得られる下部クラッド層上
に低濃度フッ素添加ＳｉＯ2 層を形成し、さらに上記低
濃度フッ素添加ＳｉＯ2 を加工して略矩形状断面を有す
るコアとし、さらに次いで上記低濃度フッ素添加ＳｉＯ
2 コアの両側面と上面とに接する高濃度フッ素添加Ｓｉ
Ｏ2 上部クラッド層を形成する導波路の製造方法であ
る。The method of manufacturing a waveguide according to the present invention, which is embodied as a group, comprises a step of forming a high concentration fluorine-doped S
In a method of manufacturing a waveguide having a structure in which a low-concentration fluorine-added SiO 2 core having a substantially rectangular cross section is embedded in an iO 2 layer, a Si substrate is used as the substrate, Forming a SiO 2 buffer layer, forming a high-concentration fluorine-added SiO 2 lower cladding layer on the obtained SiO 2 buffer layer, and then forming a low-concentration fluorine-containing SiO 2 layer on the obtained lower cladding layer; The low-concentration fluorine-added SiO 2 is processed into a core having a substantially rectangular cross section, and then the low-concentration fluorine-added SiO 2 is processed.
2 High-concentration fluorine-doped Si contacting both sides and top surface of core
This is a method for manufacturing a waveguide for forming an O 2 upper cladding layer.
【００３８】本発明の導波路の製造方法であって、具体
化された一群のものは、基板上に、高濃度フッ素添加Ｓ
ｉＯ2 層の中に、略矩形状の断面を有する低濃度フッ素
添加ＳｉＯ2 コアが埋込まれた構造を構成する導波路の
製造方法において、上記基板としてＳｉ基板を用い、上
記Ｓｉ基板上にＳｉＯ2 バッファ層を形成し、得られる
ＳｉＯ2 バッファ層上に高濃度フッ素添加ＳｉＯ2 下部
クラッド層を形成し、次いで得られる下部クラッド層上
に低濃度フッ素添加ＳｉＯ2 層を形成し、さらに上記低
濃度フッ素添加ＳｉＯ2 を加工して略矩形状断面を有す
るコアとし、さらに次いで上記低濃度フッ素添加ＳｉＯ
2 コアの両側面と上面とに接する高濃度フッ素添加Ｓｉ
Ｏ2 上部クラッド層を形成して得られる構造物を高温熱
処理して上記高濃度フッ素添加ＳｉＯ2 上部クラッド層
中のフッ素が表面側で低濃度で深部で高濃度である濃度
勾配を有するように分布させる導波路の製造方法であ
る。本発明の導波路およびその製造方法は、次のような
効果を奏する。A method of manufacturing a waveguide according to the present invention, which is embodied as a group, comprises a step of forming a high-concentration fluorine-doped S
In a method of manufacturing a waveguide having a structure in which a low-concentration fluorine-added SiO 2 core having a substantially rectangular cross section is embedded in an iO 2 layer, a Si substrate is used as the substrate, Forming a SiO 2 buffer layer, forming a high-concentration fluorine-added SiO 2 lower cladding layer on the obtained SiO 2 buffer layer, and then forming a low-concentration fluorine-containing SiO 2 layer on the obtained lower cladding layer; The low-concentration fluorine-added SiO 2 is processed into a core having a substantially rectangular cross section, and then the low-concentration fluorine-added SiO 2 is processed.
2 High-concentration fluorine-doped Si contacting both sides and top surface of core
The structure obtained by forming the O 2 upper cladding layer is subjected to a high-temperature heat treatment so that the fluorine in the high-concentration fluorine-doped SiO 2 upper cladding layer has a concentration gradient of a low concentration on the surface side and a high concentration in the deep part. This is a method of manufacturing a waveguide to be distributed. The waveguide of the present invention and the method of manufacturing the same have the following effects.
【００３９】（１）Ｏ−Ｈ基、Ｎ−Ｈ基、Ｓｉ−Ｈ基の
混入を制御し、散乱損失が低く、また吸収損失の少ない
低損失導波路を実現する。(1) A low-loss waveguide with low scattering loss and low absorption loss is realized by controlling the mixing of OH groups, NH groups and Si-H groups.
【００４０】（２）クラッド層、コア層共に、フッ素添
加ＳｉＯ2 膜で形成するので、製造プロセスが簡単であ
る。高温熱処理によるフッ素の拡散制御が簡単で、導波
路の設計が容易である。(2) Since both the cladding layer and the core layer are formed of a fluorine-added SiO 2 film, the manufacturing process is simple. The diffusion control of fluorine by high-temperature heat treatment is simple, and the design of the waveguide is easy.
【００４１】（３）コア層内およびクラッド層内のＯ−
Ｈ基、Ｎ−Ｈ基、Ｓｉ−Ｈ基が除去されるので、低損失
特性が良く、且つ、長期的な損失特性の劣化がほとんど
ない。(3) O- in the core layer and the clad layer
Since the H group, the NH group, and the Si-H group are removed, the low loss characteristics are good, and there is almost no deterioration in the long-term loss characteristics.
【００４２】（従来の導波路には上記吸収基が少なから
ず含まれているので、これらの吸収基が長期的に拡散し
てコア層内に入り、損失増大要因となる。） （４）上部クラッド層表面の低フッ素濃度化により、フ
ッ素の吸湿性による膜質劣化が防止される。(Because the conventional waveguide contains a considerable amount of the above-mentioned absorbing groups, these absorbing groups diffuse in the long term and enter the core layer, which causes an increase in loss.) By lowering the fluorine concentration on the surface of the cladding layer, deterioration of the film quality due to the hygroscopicity of fluorine is prevented.
【００４３】（５）上部クラッド層内にホウ素（Ｂ）成
分かリン（Ｐ）成分、あるいはその両成分を共添加させ
ることにより、上部クラッド層の高温熱処理時のリフロ
ー性を向上し、コアとコアの間隔の狭い領域の上部クラ
ッド層の埋め込み性を改良した。(5) By adding a boron (B) component, a phosphorus (P) component, or both components in the upper cladding layer, reflow properties of the upper cladding layer during high-temperature heat treatment are improved, and The embedding property of the upper cladding layer in the area where the core interval is small was improved.
【００４４】（６）フッ素の濃度だけで、比屈折率差
（△）が０．数％から１．５％の範囲に有する導波路を
実現することができる。(6) The relative refractive index difference (△) is set to 0.1 only by the concentration of fluorine. A waveguide having a range of several percent to 1.5 percent can be realized.
【００４５】[0045]
【実施例】図１は、本発明の導波路の一実施形態の概観
斜視図である。FIG. 1 is a schematic perspective view of an embodiment of the waveguide of the present invention.
【００４６】図２は、膜中のフッ素濃度（％）−屈折率
（波長０．６３μｍ）関係図である。FIG. 2 is a graph showing the relationship between the fluorine concentration (%) in the film and the refractive index (wavelength: 0.63 μm).
【００４７】図３は、膜の波数（ｃｍ-1）−透過率
（％）関係図である。（実線は熱処理前、破線は熱処理
後。）図４は、導波路の波長（μｍ）−吸収損失（ｄＢ
／ｃｍ）関係図である。FIG. 3 is a graph showing the relationship between the wave number (cm -1 ) and the transmittance (%) of the film. (The solid line is before the heat treatment and the broken line is after the heat treatment.) FIG. 4 shows the wavelength (μm) -absorption loss (dB) of the waveguide.
/ Cm) FIG.
【００４８】以下、図１〜４に基づいて本発明の導波路
の一実施形態について説明する。Hereinafter, one embodiment of the waveguide of the present invention will be described with reference to FIGS.
【００４９】図１に示される導波路は、石英ガラス（Ｓ
ｉＯ2 ）基板上２０上に形成された高濃度フッ素添加Ｓ
ｉＯ2 クラッド層２１中に略矩形状断面を有する低濃度
フッ素添加ＳｉＯ2 コア２２が埋込まれた構造を有する
導波路である。The waveguide shown in FIG. 1 is made of quartz glass (S
iO 2 ) High concentration fluorine added S formed on substrate 20
This is a waveguide having a structure in which a low-concentration fluorine-added SiO 2 core 22 having a substantially rectangular cross section is embedded in an iO 2 cladding layer 21.
【００５０】上記フッ素濃度は、図２に示されるＳｉＯ
2 中のフッ素濃度と屈折率との関係から理解されるよう
に、最大約５％までの範囲で選択可能である。また、ク
ラッド層２１およびコア２２のフッ素濃度差を加減する
ことによって、クラッド層２１−コア２２間の屈折率差
（△）を０．数％から１．５％の範囲に選択することが
できる。The above-mentioned fluorine concentration is determined by the SiO 2 shown in FIG.
As can be understood from the relationship between the fluorine concentration and the refractive index in 2 , the range can be selected up to a maximum of about 5%. Further, by adjusting the difference in fluorine concentration between the cladding layer 21 and the core 22, the difference in refractive index (率) between the cladding layer 21 and the core 22 is reduced to 0.1. It can be selected from a range of several percent to 1.5 percent.
【００５１】また、高濃度フッ素添加ＳｉＯ2 クラッド
層２１の膜の膜形成直後および酸素雰囲気中で１２００
℃、３時間熱処理後における赤外吸収スペクトルは図３
の通りであって、未熱処理膜は、ＯＨ基による大きな吸
収損失とＳｉ−Ｈ基による大きな吸収損失とが認められ
ている（実線）が、熱処理膜はＯＨ基およびＳｉ−Ｈ
（Ｎ−Ｈ）基による吸収損失が大幅激減する。[0051] Immediately after the formation of the high-concentration fluorine-added SiO 2 cladding layer 21 and 1200 hours in an oxygen atmosphere.
Fig. 3 shows the infrared absorption spectrum after heat treatment at 3 ° C for 3 hours.
As shown in the figure, in the unheat-treated film, a large absorption loss due to the OH group and a large absorption loss due to the Si—H group were recognized (solid line).
Absorption loss due to the (N-H) group is drastically reduced.
【００５２】即ち、高温熱処理によって、膜中のＳｉＦ
基が切れてフッ素（Ｆ）はＯＨ基と結合してＨＦとなっ
て膜外へ拡散・放出されるために、Ｓｉ−Ｈ（Ｎ−Ｈ）
基およびＯＨ基による吸収損失が激減すると考えられ
る。なお、熱処理を窒素雰囲気中で行った場合には充分
な効果が得られなかった。That is, by the high temperature heat treatment, the SiF
Since the group is cut and fluorine (F) is bonded to the OH group to form HF and diffused and released out of the film, Si-H (N-H)
It is believed that the absorption loss due to groups and OH groups is drastically reduced. When the heat treatment was performed in a nitrogen atmosphere, a sufficient effect was not obtained.
【００５３】図１に示される導波路を、基板上に高濃度
フッ素添加バッファ層を形成し、次いでコア層形成後
（コア層のパターニング前）に酸素雰囲気中で且つ、１
２００℃で熱処理し、次いでコア層をパターニングし、
さらに高濃度フッ素添加クラッド層を形成する工程で製
造した場合の、導波路の損失波長特性は、図４に示され
ている。即ち、１．３９μｍにおけるＯＨ基による吸収
損失および１．５μｍにおけるＳｉ−Ｈ（Ｎ−Ｈ）基に
よる吸収損失は認められない。なお、屈折率差（△）は
約１％とした。The waveguide shown in FIG. 1 is formed by forming a high-concentration fluorine-doped buffer layer on a substrate and then forming the core layer (before patterning of the core layer) in an oxygen atmosphere and for 1 hour.
Heat treatment at 200 ° C., then pattern the core layer,
FIG. 4 shows the loss wavelength characteristics of the waveguide when the waveguide is manufactured in the step of forming the high-concentration fluorine-added cladding layer. That is, absorption loss due to the OH group at 1.39 μm and absorption loss due to the Si—H (N—H) group at 1.5 μm are not observed. Note that the refractive index difference (△) was set to about 1%.
【００５４】図５は、本発明の導波路の他の実施形態の
概観斜視図である。FIG. 5 is a schematic perspective view of another embodiment of the waveguide of the present invention.
【００５５】図５に示される導波路は、ＳｉＯ2 基板２
０上に形成された高濃度フッ素添加ＳｉＯ2 下部クラッ
ド層２３と低濃度フッ素添加ＳｉＯ2 コア２２と、上記
コア２２の両側面および上面に接する高濃度フッ素添加
ＳｉＯ2 上部クラッド層２４とから構成される導波路で
ある。[0055] waveguide shown in FIG. 5, SiO 2 substrate 2
And a high-concentration fluorine-added SiO 2 lower cladding layer 23 formed on top of the core 22, a low-concentration fluorine-added SiO 2 core 22, and a high-concentration fluorine-added SiO 2 upper cladding layer 24 in contact with both side surfaces and the upper surface of the core 22. Waveguide.
【００５６】図６は、本発明の導波路の他の実施形態の
概観斜視図である。FIG. 6 is a schematic perspective view of another embodiment of the waveguide of the present invention.
【００５７】図６に示される導波路は、Ｓｉ基板上にＳ
ｉＯ2 バッファ層２５を形成し、バッファ層２５の上に
形成された高濃度フッ素添加ＳｉＯ2 下部クラッド層２
３を形成し、低濃度フッ素添加添加ＳｉＯ2 コア２２の
両側面および上面に接する高濃度フッ素添加ＳｉＯ2 上
部クラッド層２４とから構成される導波路である。The waveguide shown in FIG.
An iO 2 buffer layer 25 is formed, and a high-concentration fluorine-added SiO 2 lower cladding layer 2 formed on the buffer layer 25 is formed.
3 is a waveguide composed of a high-concentration fluorine-added SiO 2 upper cladding layer 24 in contact with both side surfaces and an upper surface of the low-concentration fluorine-added SiO 2 core 22.
【００５８】図７は、本発明の導波路の他の実施形態の
概観斜視図である。FIG. 7 is a schematic perspective view of another embodiment of the waveguide of the present invention.
【００５９】図８は、フッ素添加ＳｉＯ2 膜中のフッ素
濃度分布の熱処理温度による変化図である。FIG. 8 is a graph showing changes in the fluorine concentration distribution in the fluorine-added SiO 2 film depending on the heat treatment temperature.
【００６０】図７に示される導波路は、ＳｉＯ2 基板２
０上に形成された高濃度フッ素添加ＳｉＯ2 下部クラッ
ド層２３と、低濃度フッ素添加ＳｉＯ2 コア２２と、上
記コア２２の両側面および上面に接する高濃度フッ素添
加ＳｉＯ2 上部クラッド層２４とから構成され、且つ上
記上部クラッド２４中のフッ素が、上表面側では低濃度
でその内部では高濃度であるような厚さ方向の濃度勾配
を有するように分布している導波路である。このような
フッ素の厚さ方向の濃度勾配分布は、高濃度フッ素添加
ＳｉＯ2 上部クラッド層２４を有する導波路を１０００
℃〜１２５０℃の温度で熱処理することによって実現さ
れる。[0060] waveguide shown in FIG. 7, SiO 2 substrate 2
0, a low-concentration fluorine-added SiO 2 lower cladding layer 23, a low-concentration fluorine-added SiO 2 core 22, and a high-concentration fluorine-doped SiO 2 upper cladding layer 24 in contact with both side surfaces and the upper surface of the core 22. The waveguide is configured so that the fluorine in the upper cladding 24 is distributed so as to have a concentration gradient in the thickness direction such that the concentration is low on the upper surface side and high in the inside. Such a concentration gradient distribution of fluorine in the thickness direction indicates that the waveguide having the high-concentration fluorine-added SiO 2
This is realized by performing a heat treatment at a temperature of from 1C to 1250C.
【００６１】図８に示されるように、形成直後（ａｓ
ｄｅｐｏ．）の高濃度フッ素添加ＳｉＯ2 膜中のフッ素
分布における濃度勾配は無視できる。このような高濃度
フッ素添加ＳｉＯ2 膜を例えば１０００℃で熱処理する
と表面から浅い部分でフッ素濃度が低下し、より深部で
はフッ素濃度が増加することが判る。As shown in FIG. 8, immediately after formation (as
depo. The concentration gradient in the distribution of fluorine in the high-concentration fluorine-added SiO 2 film of (3) can be ignored. It can be seen that when such a high-concentration fluorine-added SiO 2 film is heat-treated at, for example, 1000 ° C., the fluorine concentration decreases in a portion shallow from the surface and increases in a deeper portion.
【００６２】このように、ＳｉＯ2 膜表面のフッ素濃度
を低下させると、吸湿性を大幅に改善することができ、
長期的に安定な導波路を実現することができる。As described above, when the fluorine concentration on the surface of the SiO 2 film is reduced, the hygroscopicity can be greatly improved.
A long-term stable waveguide can be realized.
【００６３】図９は、本発明の導波路の他の実施形態の
概観斜視図である。FIG. 9 is a schematic perspective view of another embodiment of the waveguide of the present invention.
【００６４】図９に示される導波路は、ＳｉＯ2 基板２
０上に形成された高濃度フッ素添加ＳｉＯ2 下部クラッ
ド層２３を形成し、これに下面を接する略矩形状断面を
有する低濃度フッ素添加ＳｉＯ2 コア２２−１および２
２−２を形成し、その両側面および上面に接して埋込む
高濃度フッ素添加−ホウ素（Ｂ）成分、リン（Ｐ）成分
共添加ＳｉＯ2 上部クラッド２４を形成した構造を有す
る導波路である。[0064] waveguide shown in FIG. 9, SiO 2 substrate 2
A low-concentration fluorine-added SiO 2 cores 22-1 and 2 having a substantially rectangular cross-section and having a lower surface in contact with a high-concentration fluorine-added SiO 2 lower cladding layer 23 formed on
2-2 is a waveguide having a structure in which an SiO 2 upper clad 24 is formed which is doped with high-concentration fluorine-doped boron (B) component and phosphorus (P) component and is embedded in contact with both side surfaces and the upper surface thereof. .
【００６５】フッ素−ホウ素（Ｂ）−リン（Ｐ）共添加
ＳｉＯ2 上部クラッド層は、コア２２−１とコア２２−
２の間隔ｄが１．５μｍ〜３μｍのように接近している
場合の埋込に好適である。即ち、１２００℃で高温熱処
理すると上記共添加ＳｉＯ2上部クラッド層は軟化点が
低いのでリフローを生じて狭い間隔ｄの場合でも気泡を
抱込むことなくコアの埋込ができる。なお、ホウ素
（Ｂ）とリン（Ｐ）の添加濃度は、数モル％から十数モ
ル％の範囲で選ぶことができる。（図１３参照。）図１
０は、本発明の導波路製造方法に用いられるプラズマＣ
ＶＤ装置の概略図である。なお、図１４に示した部材と
同様の部材には共通の符号を用いた。The fluorine-boron (B) -phosphorus (P) -codoped SiO 2 upper cladding layer comprises a core 22-1 and a core 22-
It is suitable for embedding when the interval d of 2 is as close as 1.5 μm to 3 μm. In other words, when the heat treatment is performed at 1200 ° C. at a high temperature, the co-added SiO 2 upper cladding layer has a low softening point, so that reflow occurs and the core can be buried without enclosing bubbles even at a narrow interval d. Note that the addition concentration of boron (B) and phosphorus (P) can be selected in the range of several mol% to more than ten mol%. (See FIG. 13) FIG.
0 is the plasma C used in the waveguide manufacturing method of the present invention.
It is a schematic diagram of a VD device. The same members as those shown in FIG. 14 are denoted by the same reference numerals.
【００６６】図１０に示されるプラズマＣＶＤ装置は、
反応容器６と、反応容器６を真空排気する排気装置５
と、反応容器６内の上部に水平に配置された上部電極７
と、上部電極７の下側に対向配置された下部電極８と、
両電極７，８間に接続された高周波電源９と、下部電極
８の下側に設けられたヒータ１１と、ヒータ１１に接続
された直流電源１２と、上部電極７の下側に形成された
ガス噴出口を介して反応容器６内に所定のガスを供給す
るためのガス供給管２８と、ガス供給管２８の周囲に設
けられたヒータ２９−１，２９−２と、ヒータ２９−
１，２９−２にそれぞれ接続された直流電源３０−１，
３０−２と、反応容器６内に上記ガス供給管２８と独立
してガスを供給するガス供給管３１とで構成されてい
る。The plasma CVD apparatus shown in FIG.
Reaction vessel 6 and exhaust device 5 for evacuating reaction vessel 6
And an upper electrode 7 horizontally arranged at the upper part in the reaction vessel 6.
A lower electrode 8 opposed to the lower side of the upper electrode 7,
A high-frequency power supply 9 connected between the electrodes 7 and 8; a heater 11 provided below the lower electrode 8; a DC power supply 12 connected to the heater 11; A gas supply pipe 28 for supplying a predetermined gas into the reaction vessel 6 through the gas outlet, heaters 29-1 and 29-2 provided around the gas supply pipe 28, and a heater 29-
DC power supplies 30-1, 30-1,
30-2, and a gas supply pipe 31 for supplying a gas into the reaction vessel 6 independently of the gas supply pipe 28.
【００６７】プラズマＣＶＤ装置により、基板２０上に
高濃度フッ素添加ＳｉＯ2 クラッド層２１、ＳｉＯ2 バ
ッファ層２５、低濃度フッ素添加ＳｉＯ2 コア２２等の
ための膜が形成させる。Films for the high-concentration fluorine-added SiO 2 cladding layer 21, the SiO 2 buffer layer 25, the low-concentration fluorine-added SiO 2 core 22, and the like are formed on the substrate 20 by the plasma CVD apparatus.
【００６８】反応容器６は排気装置５によって真空排気
される。下部電極８上に載置された基板２０はヒータ１
１の通電によって１００℃から５００℃の温度範囲で加
熱される。上部電極７と下部電極８との間には高周波電
圧が印加される。上部電極７内には、矢印３２−１方向
から矢印３２−２方向に向かってガラス原料ガス、酸化
性ガス及び不活性ガス等が送り込まれる。また、矢印３
３方向からも両電極７，８間にフッ素添加用ガス（Ｃ2
Ｆ6 ，ＣＦ4 などのフッ素化炭化水素）などを取り込む
こともできる。矢印３２−１方向から矢印３２−２方向
へ送り込まれるガスは、ヒータ２９−１，２９−２に直
流電圧を印加することによって加熱される。The reaction vessel 6 is evacuated by the exhaust device 5. The substrate 20 placed on the lower electrode 8 is a heater 1
Heating is performed in the temperature range of 100 ° C. to 500 ° C. by the energization of 1. A high-frequency voltage is applied between the upper electrode 7 and the lower electrode 8. Glass raw material gas, oxidizing gas, inert gas, and the like are fed into the upper electrode 7 from the direction of the arrow 32-1 to the direction of the arrow 32-2. Arrow 3
Fluorine addition gas (C 2
Fluorinated hydrocarbons such as F 6 and CF 4 ) can also be incorporated. The gas fed from the direction of the arrow 32-1 to the direction of the arrow 32-2 is heated by applying a DC voltage to the heaters 29-1 and 29-2.
【００６９】プラズマＣＶＤ装置で前述した各種の膜を
形成するには、まず真空排気されている反応容器６内に
矢印３２−１方向などからＡｒガスを供給して両電極
７，８間にプラズマ１４を発生させる。ついで、矢印３
２−１方向などから例えばＳｉＨ4 ，Ｏ2 ，Ｃ2 Ｆ6 ，
Ａｒ等のガスを流してプラズマ１４に送り、フッ素添加
ＳｉＯ2 膜を形成する。In order to form the above-mentioned various films using a plasma CVD apparatus, first, an Ar gas is supplied into the evacuated reaction vessel 6 from the direction of arrow 32-1 or the like, and the plasma is applied between the electrodes 7 and 8. 14 is generated. Then arrow 3
For example, SiH 4 , O 2 , C 2 F 6 ,
A gas such as Ar is flowed and sent to the plasma 14 to form a fluorine-added SiO 2 film.
【００７０】また、フッ素にホウ素（Ｂ）成分かリン
（Ｐ）成分、あるいはその両成分を共添加ＳｉＯ2 上部
クラッド２４を形成する場合は、矢印３２−１方向など
からケイ素（Ｓｉ）成分原料（ＳｉＨ4 ，Ｓｉ（ＯＣ2
Ｈ5 ）4 など）、フッ素原料（Ｃ2 Ｆ6 など）、ホウ素
（Ｂ）成分原料（Ｂ2 Ｈ6 、Ｂ（ＯＣ2 Ｈ5 ）3 など）
と酸化性ガス（Ｏ2 など）を必要に応じてキャリアガス
（Ａｒなど）と共に流してプラズマ１４に送ってフッ素
−Ｂ−Ｐ共添加ＳｉＯ2 膜を形成する。When the SiO 2 upper clad 24 is formed by adding a boron (B) component, a phosphorus (P) component, or both components to fluorine, a silicon (Si) component material may be used in the direction of arrow 32-1 or the like. (SiH 4 , Si (OC 2
H 5) 4, etc.), such as a fluorine raw material (C 2 F 6), boron (B) ingredient material (such as B 2 H 6, B (OC 2 H 5) 3)
Then, an oxidizing gas (such as O 2 ) is flowed together with a carrier gas (such as Ar) as necessary and sent to the plasma 14 to form a fluorine-BP-Co-added SiO 2 film.
【００７１】なお、上記各種膜は、プラズマＣＶＤ法で
形成する以外に、火炎堆積法を用いてスート状の多孔質
膜を形成し、得られる多孔質膜を電気炉中でＨｅガスを
流しながら焼結（１３５０℃前後）して透明化する方法
も用いられる。In addition to the above-mentioned various films, a soot-like porous film is formed by a flame deposition method in addition to the plasma CVD method, and the obtained porous film is formed while flowing He gas in an electric furnace. A method of sintering (around 1350 ° C.) to make it transparent is also used.
【００７２】[0072]
【発明の効果】吸収損失などの小さい、高比屈折率
（△）導波路およびその製造方法を可能とする。According to the present invention, a high relative refractive index (△) waveguide having a small absorption loss and the like and a method for manufacturing the same can be realized.
【図１】本発明の導波路の一実施形態を示す概観斜視図
である。FIG. 1 is a schematic perspective view showing one embodiment of a waveguide of the present invention.
【図２】膜中のフッ素濃度−屈折率関係図である。FIG. 2 is a diagram showing a relationship between a fluorine concentration in a film and a refractive index.
【図３】膜の波長（ｃｍ-1）−透過率関係図である。FIG. 3 is a diagram showing the relationship between the wavelength (cm −1 ) and the transmittance of a film.
【図４】導波路の波長（μｍ）−吸収損失（ｄＢ／ｃ
ｍ）関係図である。FIG. 4 Wavelength (μm) of waveguide—absorption loss (dB / c)
m) It is a related figure.
【図５】本発明の導波路の他の実施形態を示す概観斜視
図である。FIG. 5 is a schematic perspective view showing another embodiment of the waveguide of the present invention.
【図６】本発明の導波路の他の実施形態を示す概観斜視
図である。FIG. 6 is a schematic perspective view showing another embodiment of the waveguide of the present invention.
【図７】本発明の導波路の他の実施形態を示す概観斜視
図である。FIG. 7 is a schematic perspective view showing another embodiment of the waveguide of the present invention.
【図８】膜中のフッ素濃度分布の熱処理による変化図で
ある。FIG. 8 is a diagram showing a change in a fluorine concentration distribution in a film due to heat treatment.
【図９】本発明の導波路の他の実施形態を示す概観斜視
図である。FIG. 9 is a schematic perspective view showing another embodiment of the waveguide of the present invention.
【図１０】本発明の導波路の製造方法に用いられるプラ
ズマＣＶＤ装置の概略図である。FIG. 10 is a schematic view of a plasma CVD apparatus used in the waveguide manufacturing method of the present invention.
【図１１】ＳｉＯＮＨコアを有する導波路の概観斜視図
である。FIG. 11 is a schematic perspective view of a waveguide having a SiONH core.
【図１２】ＳｉＯＮＨ膜中の窒素含有率−屈折率関係図
である。FIG. 12 is a diagram showing a relationship between a nitrogen content and a refractive index in a SiONH film.
【図１３】屈折率制御添加物濃度−屈折率関係図であ
る。FIG. 13 is a graph showing the relationship between the concentration of a refractive index control additive and the refractive index.
【図１４】プラズマＣＶＤ装置の概略図である。FIG. 14 is a schematic view of a plasma CVD apparatus.
【図１５】導波路の波長（μｍ）−吸収損失（ｄＢ／ｃ
ｍ）関係図である。FIG. 15: Wavelength (μm) of waveguide—absorption loss (dB / c)
m) It is a related figure.
１，２０ 基板 ２，２３ 下部クラッド層 ３，２２ コア ４，２４ 上部クラッド層 ２１ クラッド層 ２５ バッファ層 DESCRIPTION OF SYMBOLS 1, 20 Substrate 2, 23 Lower cladding layer 3, 22 Core 4, 24 Upper cladding layer 21 Cladding layer 25 Buffer layer
Claims (15)
濃度フッ素添加ＳｉＯ2 層の中に、略矩形状の断面を有
するコアが埋め込まれた構造を有し、且つ、上記コアが
低濃度フッ素添加ＳｉＯ2 から成る導波路。1. A waveguide formed on a substrate, having a structure in which a core having a substantially rectangular cross section is embedded in a high-concentration fluorine-added SiO 2 layer, and wherein the core is A waveguide made of low-concentration fluorine-doped SiO 2 .
ｉＯ2 層の中に略矩形状の断面を有するコアが埋め込ま
れた構造を有し、且つ、上記コアが低濃度フッ素添加Ｓ
ｉＯ2 から成る導波路において、上記高濃度フッ素添加
ＳｉＯ2 層が、上記コアの下面に接する下部クラッド層
と、上記コアの側面および上面に接する上部クラッド層
とで構成された導波路。2. A high-concentration fluorine-doped S formed on a substrate.
It has a structure in which a core having a substantially rectangular cross section is embedded in an iO 2 layer, and the core has a low concentration of fluorine-doped S
A waveguide comprising iO 2, wherein the high-concentration fluorine-doped SiO 2 layer is constituted by a lower cladding layer in contact with the lower surface of the core and an upper cladding layer in contact with the side and upper surfaces of the core.
ｉＯ2 層の中に略矩形状の断面を有するコアが埋め込ま
れた構造を有し、且つ、上記コアが低濃度フッ素添加Ｓ
ｉＯ2 から成り、さらに上記高濃度フッ素添加ＳｉＯ2
層が、上記コアの下面に接する下部クラッド層と、上記
コアの側面および上面に接する上部クラッド層とで構成
される導波路において、上記上部クラッド層中のフッ素
濃度が厚さ方向の勾配を有するように分布している導波
路。3. A high-concentration fluorine-doped S formed on a substrate.
It has a structure in which a core having a substantially rectangular cross section is embedded in an iO 2 layer, and the core has a low concentration of fluorine-doped S
It consists iO 2, further the high concentration fluorine-added SiO 2
In a waveguide in which a layer is formed of a lower clad layer in contact with the lower surface of the core and an upper clad layer in contact with the side surface and the upper surface of the core, the fluorine concentration in the upper clad layer has a gradient in the thickness direction. Waveguides that are distributed like.
ｉＯ2 層の中に略矩形状の断面を有するコアが埋め込ま
れた構造を有し、且つ、上記コアが低濃度フッ素添加Ｓ
ｉＯ2 から成り、さらに上記高濃度フッ素添加ＳｉＯ2
層が、上記コアの下面に接する下部クラッド層と、上記
コアの側面および上面に接する上部クラッド層とで構成
される導波路において、上記上部クラッド層が、ホウ素
（Ｂ）成分かリン（Ｐ）成分、あるいはその両成分を共
添加されている導波路。4. A high-concentration fluorine-added S formed on a substrate
It has a structure in which a core having a substantially rectangular cross section is embedded in an iO 2 layer, and the core has a low concentration of fluorine-doped S
It consists iO 2, further the high concentration fluorine-added SiO 2
In a waveguide whose layer is composed of a lower clad layer in contact with the lower surface of the core and an upper clad layer in contact with the side surface and the upper surface of the core, the upper clad layer is composed of a boron (B) component or phosphorus (P). A waveguide in which a component or both components are co-doped.
２、３または４記載の導波路。5. The method of claim 1, wherein said substrate comprises SiO 2 .
The waveguide according to 2, 3, or 4.
にＳｉＯ2 バッファ層を設けたものである請求項１記載
の導波路。6. The waveguide according to claim 1, wherein the substrate is a Si substrate or a substrate provided with a SiO 2 buffer layer on the Si substrate.
部クラッド層との間にＳｉＯ2 バッファ層を設けた請求
項２、３または４記載の導波路。7. The waveguide according to claim 2 , wherein the substrate is made of Si, and an SiO 2 buffer layer is provided between the substrate and the lower cladding layer.
るコア層形成後、またはコア層の略矩形断面パターニン
グ後または高濃度フッ素添加ＳｉＯ2 層へのコア埋込後
の何れかの段階において、酸素雰囲気中且つ１０００℃
〜１２５０℃の温度範囲で少なくとも１回熱処理されて
いる請求項１、２、３、４、５、６または７記載の導波
路。8. The waveguide may be formed at any stage after the formation of the core layer in the formation process of the waveguide, after the patterning of the core layer in a substantially rectangular cross section, or after the embedding of the core in the high-concentration fluorine-added SiO 2 layer. 1000 ° C. in oxygen atmosphere
The waveguide according to claim 1, 2, 3, 4, 5, 6, or 7, which has been heat-treated at least once in a temperature range of 1250C.
０℃〜１２５０℃の温度範囲で少なくとも１回熱処理さ
れている請求項１、２、３、４、５、６または７記載の
導波路。9. The method according to claim 1, wherein the waveguide is in an oxygen atmosphere and at 100
The waveguide according to claim 1, wherein the waveguide is heat-treated at least once in a temperature range of 0 ° C. to 1250 ° C. 9.
ッ素化炭化水素を使用するプラズマＣＶＤ法によって成
膜された高濃度フッ素添加ＳｉＯ2 から形成され、上記
コアがフッ素化炭化水素を使用するプラズマＣＶＤ法に
よって成膜された低フッ素添加ＳｉＯ2 から形成された
請求項１、２、３、４、５、６、７または８記載の導波
路。10. The high-concentration fluorine-added SiO 2 layer is formed from high-concentration fluorine-added SiO 2 formed by a plasma CVD method using a fluorinated hydrocarbon, and the core is a plasma using a fluorinated hydrocarbon. 9. The waveguide according to claim 1, wherein the waveguide is formed from low-fluorine-added SiO 2 formed by a CVD method.
層の中に、略矩形状の断面を有する低濃度フッ素添加Ｓ
ｉＯ2 コアが埋込まれた構造を構成する導波路の製造方
法において、上記高濃度フッ素添加ＳｉＯ2 および低濃
度フッ素添加ＳｉＯ2 を、必須の反応成分としてケイ素
（Ｓｉ）原料であるシランあるいは有機オキシシランと
フッ素（Ｆ）原料であるフッ素化炭化水素と酸化性ガス
とを反応させるプラズマＣＶＤ法を用いて製造する導波
路の製造方法。11. A high-concentration fluorine-added SiO 2 is formed on a substrate.
In the layer, a low-concentration fluorine-doped S having a substantially rectangular cross section is used.
In the method of manufacturing a waveguide having a structure in which an iO 2 core is embedded, the high-concentration fluorine-added SiO 2 and the low-concentration fluorine-added SiO 2 are used as essential reaction components in a silane or organic material as a silicon (Si) raw material. A method for manufacturing a waveguide manufactured by using a plasma CVD method in which oxysilane, a fluorinated hydrocarbon as a raw material of fluorine (F), and an oxidizing gas are reacted.
層の中に、略矩形状の断面を有する低濃度フッ素添加Ｓ
ｉＯ2 コアが埋込まれた構造を構成する導波路の製造方
法において、上記基板としてＳｉＯ2 基板を用い、基板
上に高濃度フッ素添加ＳｉＯ2 下部クラッド層を形成
し、次いで得られる下部クラッド層上に低濃度フッ素添
加ＳｉＯ2 層を形成し、さらに上記低濃度フッ素添加Ｓ
ｉＯ2 を加工して略矩形状断面を有するコアとし、さら
に次いで上記低濃度フッ素添加ＳｉＯ2 コアの両側面と
上面とに接する高濃度フッ素添加ＳｉＯ2 上部クラッド
層を形成する導波路の製造方法。12. A high-concentration fluorine-added SiO 2 is formed on a substrate.
In the layer, a low-concentration fluorine-doped S having a substantially rectangular cross section is used.
In a method of manufacturing a waveguide having a structure in which an iO 2 core is embedded, an SiO 2 substrate is used as the substrate, a high-concentration fluorine-added SiO 2 lower cladding layer is formed on the substrate, and then the obtained lower cladding layer A low-concentration fluorine-added SiO 2 layer is formed thereon, and
A method of manufacturing a waveguide in which iO 2 is processed into a core having a substantially rectangular cross-section, and then a high-concentration fluorine-added SiO 2 upper clad layer is formed in contact with both side surfaces and the upper surface of the low-concentration fluorine-added SiO 2 core .
層の中に、略矩形状の断面を有する低濃度フッ素添加Ｓ
ｉＯ2 コアが埋込まれた構造を構成する導波路の製造方
法において、上記基板としてＳｉＯ2 基板を用い、基板
上に高濃度フッ素添加ＳｉＯ2 下部クラッド層を形成
し、次いで得られる下部クラッド層上に低濃度フッ素添
加ＳｉＯ2 層を形成し、さらに上記低濃度フッ素添加Ｓ
ｉＯ2 を加工して略矩形状断面を有するコアとし、さら
に次いで上記低濃度フッ素添加ＳｉＯ2 コアの両側面と
上面とに接する高濃度フッ素添加ＳｉＯ2 上部クラッド
層を形成して得られる構造物を高温熱処理して上記高濃
度フッ素添加ＳｉＯ2 上部クラッド層中のフッ素が表面
側で低濃度で深部で高濃度である濃度勾配を有するよう
に分布させる導波路の製造方法。13. A high-concentration fluorine-doped SiO 2 layer on a substrate.
In the layer, a low-concentration fluorine-doped S having a substantially rectangular cross section is used.
In a method of manufacturing a waveguide having a structure in which an iO 2 core is embedded, an SiO 2 substrate is used as the substrate, a high-concentration fluorine-added SiO 2 lower cladding layer is formed on the substrate, and then the obtained lower cladding layer A low-concentration fluorine-added SiO 2 layer is formed thereon, and
A structure obtained by processing iO 2 into a core having a substantially rectangular cross-section, and then forming a high-concentration fluorine-added SiO 2 upper cladding layer in contact with both side surfaces and the upper surface of the low-concentration fluorine-added SiO 2 core A high-temperature heat treatment to distribute the fluorine in the high-concentration fluorine-added SiO 2 upper cladding layer so as to have a concentration gradient of low concentration on the surface side and high concentration in the deep part.
層の中に、略矩形状の断面を有する低濃度フッ素添加Ｓ
ｉＯ2 コアが埋込まれた構造を構成する導波路の製造方
法において、上記基板としてＳｉ基板を用い、上記Ｓｉ
基板上にＳｉＯ2 バッファ層を形成し、得られるＳｉＯ
2 バッファ層上に高濃度フッ素添加ＳｉＯ2 下部クラッ
ド層を形成し、次いで得られる下部クラッド層上に低濃
度フッ素添加ＳｉＯ2 層を形成し、さらに上記低濃度フ
ッ素添加ＳｉＯ2 を加工して略矩形状断面を有するコア
とし、さらに次いで上記低濃度フッ素添加ＳｉＯ2 コア
の両側面と上面とに接する高濃度フッ素添加ＳｉＯ2 上
部クラッド層を形成する導波路の製造方法。14. A high-concentration fluorine-doped SiO 2 layer on a substrate.
In the layer, a low-concentration fluorine-doped S having a substantially rectangular cross section is used.
In a method of manufacturing a waveguide having a structure in which an iO 2 core is embedded, a Si substrate is used as the substrate,
A SiO 2 buffer layer is formed on a substrate,
(2) forming a high-concentration fluorine-added SiO 2 lower clad layer on the buffer layer, forming a low-concentration fluorine-added SiO 2 layer on the obtained lower clad layer, and further processing the low-concentration fluorine-added SiO 2 A method for manufacturing a waveguide, wherein a core having a rectangular cross section is formed, and then a high-concentration fluorine-added SiO 2 upper cladding layer is formed in contact with both side surfaces and the upper surface of the low-concentration fluorine-added SiO 2 core.
層の中に、略矩形状の断面を有する低濃度フッ素添加Ｓ
ｉＯ2 コアが埋込まれた構造を構成する導波路の製造方
法において、上記基板としてＳｉ基板を用い、上記Ｓｉ
基板上にＳｉＯ2 バッファ層を形成し、得られるＳｉＯ
2 バッファ層上に高濃度フッ素添加ＳｉＯ2 下部クラッ
ド層を形成し、次いで得られる下部クラッド層上に低濃
度フッ素添加ＳｉＯ2 層を形成し、さらに上記低濃度フ
ッ素添加ＳｉＯ2 層を加工して略矩形状断面を有するコ
アとし、さらに次いで上記低濃度フッ素添加ＳｉＯ2 コ
アの両側面と上面とに接する高濃度フッ素添加ＳｉＯ2
上部クラッド層を形成して得られる構造物を高温熱処理
してフッ素が表面側で低濃度で深部で高濃度である濃度
勾配を有するように分布させる導波路の製造方法。15. A high-concentration fluorine-doped SiO 2 film on a substrate.
In the layer, a low-concentration fluorine-doped S having a substantially rectangular cross section is used.
In a method of manufacturing a waveguide having a structure in which an iO 2 core is embedded, a Si substrate is used as the substrate,
A SiO 2 buffer layer is formed on a substrate,
(2) forming a high-concentration fluorine-added SiO 2 lower cladding layer on the buffer layer, then forming a low-concentration fluorine-added SiO 2 layer on the obtained lower cladding layer, and further processing the low-concentration fluorine-added SiO 2 layer A core having a substantially rectangular cross section, and then a high-concentration fluorine-added SiO 2 contacting both side surfaces and an upper surface of the low-concentration fluorine-added SiO 2 core
A method for producing a waveguide in which a structure obtained by forming an upper clad layer is subjected to a high-temperature heat treatment to distribute fluorine so as to have a concentration gradient of a low concentration on a surface side and a high concentration in a deep part.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP02985198A JP3454134B2 (en) | 1998-02-12 | 1998-02-12 | Waveguide and manufacturing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP02985198A JP3454134B2 (en) | 1998-02-12 | 1998-02-12 | Waveguide and manufacturing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH11231152A true JPH11231152A (en) | 1999-08-27 |
| JP3454134B2 JP3454134B2 (en) | 2003-10-06 |
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ID=12287483
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP02985198A Expired - Fee Related JP3454134B2 (en) | 1998-02-12 | 1998-02-12 | Waveguide and manufacturing method thereof |
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| Country | Link |
|---|---|
| JP (1) | JP3454134B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2019203915A (en) * | 2018-05-21 | 2019-11-28 | 日本電信電話株式会社 | Optical integrated device and method for manufacturing the same |
-
1998
- 1998-02-12 JP JP02985198A patent/JP3454134B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2019203915A (en) * | 2018-05-21 | 2019-11-28 | 日本電信電話株式会社 | Optical integrated device and method for manufacturing the same |
| WO2019225329A1 (en) * | 2018-05-21 | 2019-11-28 | 日本電信電話株式会社 | Optical integrated device and production method therefor |
| US11415747B2 (en) | 2018-05-21 | 2022-08-16 | Nippon Telegraph And Telephone Corporation | Optical integrated device and production method therefor |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3454134B2 (en) | 2003-10-06 |
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