JP3677970B2

JP3677970B2 - Solid-state imaging device and manufacturing method thereof

Info

Publication number: JP3677970B2
Application number: JP28325697A
Authority: JP
Inventors: 健松田
Original assignee: Sony Corp
Current assignee: Sony Corp
Priority date: 1997-10-16
Filing date: 1997-10-16
Publication date: 2005-08-03
Anticipated expiration: 2017-10-16
Also published as: JPH11121725A

Description

【０００１】
【発明の属する技術分野】
本発明は、受光センサ部への集光効率を高め、感度特性の向上を図った固体撮像素子とその製造方法に関する。
【０００２】
【従来の技術】
固体撮像素子の微細化に伴い、特に１／４”３８万画素より小さいデバイスなどではその感度向上が必須となってきている。このような背景のもとに従来では、カラーフィルタ上にオンチップレンズを設け、集光効率を高めるといった工夫がなされている。
【０００３】
ところが、近年においてはデバイスの小型化、高感度化に伴ってさらなる集光効率の向上が望まれているものの、前述したオンチップレンズによる集光効果はほぼ限界に近づいており、オンチップレンズとは別の新たな技術の開発が望まれている。
【０００４】
このような要望に対応する技術として、オンチップレンズと併用する状態で層内レンズを設ける技術が一部に提案されている。この層内レンズは、光電変換をなす受光部の直上において層間膜中に形成されるレンズであり、オンチップレンズと同様にこの層内レンズに入射した光を該層内レンズの上面側または下面側の界面で屈折させ、受光部に導くものである。したがって、このような層間レンズを前記オンチップレンズと併用することにより、オンチップレンズで集光されて入射した光を再度層内レンズで集光することができ、これにより固体撮像素子全体としての集光効率をより高めることができるのである。
【０００５】
【発明が解決しようとする課題】
ところが、従来提案されている層内レンズはほとんどが凹型のレンズであり、これを形成する場合、遮光膜の上にＢＰＳＧ（ホウ素リンシリケートガラス）等のリフロー形状をもつ膜を形成し、転送電極間、すなわち受光部の直上に形成されたくぼみの中に高屈折率材を埋め込み、この埋め込んだ高屈折率材を層内レンズとする、といったプロセスを採るのが普通である。
しかして、このプロセスでは層内レンズの形状がリフロー膜の形状で決まってしまうことから、所望の形状、すなわち集光に最適な形状を得るのが困難であり、したがって層内レンズを設けたとはいえ未だ十分に高い集光効率を得るのが困難である。
【０００６】
本発明は前記事情に鑑みてなされたもので、その目的とするところは、層間レンズに代わる集光機能を有し、これにより集光効率の向上を図った固体撮像装置とその製造方法を提供することにある。
【０００７】
【課題を解決するための手段】
本発明における第１の固体撮像素子では、基体の表層部に設けられて光電変換をなす受光センサ部と、該受光センサ部から読み出された信号電荷を転送する電荷転送部と、前記基体上の、前記電荷転送部の略直上位置に絶縁膜を介して設けられた転送電極とを備えてなり、前記転送電極上を覆い、かつ前記受光センサ部の直上位置の一部に孔部を形成した状態で平坦化膜が設けられ、前記孔部の内面上に該内面を覆って前記平坦化膜より屈折率が大きい第１の透明膜が設けられ、さらにこの第１の透明膜の内面上に該内面覆って第１の透明膜より屈折率が小さい第２の透明膜が設けられてなることを前記課題の解決手段とした。
【０００８】
この固体撮像素子によれば、平坦化膜に形成された孔部内面上に第１の透明膜を設け、この第１の透明膜の内面上に第２の透明膜を設け、さらにこの第１の透明膜の内面上に第２の透明膜を設けたので、孔部内に入射した光のうち受光センサ部の表面に対し斜めに入射して第２の透明膜と第１の透明膜との界面に到った光が第２の透明膜と第１の透明膜との屈折率差によってこの界面で屈折し、第１の透明膜と平坦化膜との界面側に導かれる。すると、この第１の透明膜と平坦化膜との界面側に導かれた光は、第１の透明膜と平坦化膜との界面にて該第１の透明膜と平坦化膜との屈折率差により例えば全反射し、これによって孔部内に戻されて受光センサ部上に入射する。
【０００９】
本発明における第２の固体撮像素子では、基体の表層部に設けられて光電変換をなす受光センサ部と、該受光センサ部から読み出された信号電荷を転送する電荷転送部と、前記基体上の、前記電荷転送部の略直上位置に絶縁膜を介して設けられた転送電極と、該転送電極を覆い、かつ受光センサ部の直上位置の一部に開口部を形成した状態で設けられた遮光膜とを備えてなり、前記遮光膜上を覆い、かつ前記開口部に連通する孔部をその内面が前記開口部の内面に略面一となるようにして形成した状態で平坦化膜が設けられ、前記孔部および開口部の内面上に該内面を覆って前記平坦化膜より屈折率が大きい第１の透明膜が設けられてなることを前記課題の解決手段とした。
【００１０】
この固体撮像素子によれば、遮光膜上を覆い、かつ前記開口部に連通する孔部をその内面が前記開口部の内面に略面一となるようにして形成した状態で平坦化膜を設け、前記孔部および開口部の内面上に第１の透明膜を設けたので、孔部内に入射した光のうち受光センサ部の表面に対し斜めに入射して第１の透明膜に導かれさらにこの第１の透明膜と平坦化膜との界面に到った光が該第１の透明膜と平坦化膜との屈折率差により例えば全反射し、また第１の透明膜と遮光膜の開口部との界面に到った光が該開口部の内面で全反射して開口部内に戻され、受光センサ部上に入射する。
【００１１】
本発明における固体撮像素子の製造方法では、基体の表層部に設けられて光電変換をなす受光センサ部と、該受光センサ部から読み出された信号電荷を転送する電荷転送部と、前記基体上の、前記電荷転送部の略直上位置に絶縁膜を介して設けられた転送電極と、該転送電極を覆い、かつ受光センサ部の直上位置の一部に開口部を形成した状態で設けられた遮光膜とを備えてなる固体撮像素子を製造するに際して、前記転送電極を覆った状態に遮光材料膜を形成し、次に前記遮光材料膜上に平坦化膜材料を成膜し、かつ該平坦化膜材料を平坦化して平坦化膜を形成し、次いで前記受光センサ部の一部の直上位置にある前記平坦化膜と遮光膜とをエッチングすることにより該平坦化膜に形成される孔部の内面と遮光膜に形成される開口部の内面とが略面一になるようにこれら平坦化膜の孔部と遮光膜の開口部とを形成し、その後前記孔部および開口部の内面上に該内面を覆って前記平坦化膜より屈折率が大きい第１の透明膜を形成することを、を備えた前記課題の解決手段とした。
【００１２】
この固体撮像素子の製造方法によれば、平坦化膜と遮光膜とをエッチングすることにより該平坦化膜に形成される孔部の内面と遮光膜に形成される開口部の内面とが略面一になるようにこれら平坦化膜の孔部と遮光膜の開口部とを形成し、その後孔部および開口部の内面上に平坦化膜より屈折率が大きい第１の透明膜を形成するので、得られる固体撮像素子は孔部および開口部の内面上に第１の透明膜が設けられたものとなり、したがってこの固体撮像素子では、孔部内に入射した光のうち受光センサ部の表面に対し斜めに入射して第１の透明膜に導かれさらにこの第１の透明膜と平坦化膜との界面に到った光が該第１の透明膜と平坦化膜との屈折率差により例えば全反射し、また第１の透明膜と遮光膜の開口部との界面に到った光が該開口部の内面で全反射して開口部内に戻され、受光センサ部上に入射するようになる。
また、平坦化膜の膜厚を厚くすることにより、全反射をなす平坦化膜と第１の透明膜との界面の高さ（深さ）を容易に拡げることが可能となる。
【００１３】
【発明の実施の形態】
以下、本発明を詳しく説明する。
図１は本発明の固体撮像素子の一実施形態例を示す図であり、図１において符号１は固体撮像素子、２はシリコン基板（基体）である。シリコン基板２には、図１に示すようにその表層部に光電変換をなす受光部（図示略）が形成され、さらにこの受光部の上にホール蓄積部（図示略）が形成されている。そして、これら受光部とホール蓄積部とから、ＨＡＤ（Holl Accumulation Diode ）構造の受光センサ部３が形成されている。
【００１４】
この受光センサ部３の一方の側には、読み出しゲート４を介して電荷転送部５が形成され、他方の側にはチャネルストップ６を介して別の電荷転送部５が形成されている。そして、このような構成により受光センサ部３で光電変換されて得られた信号電荷は、読み出しゲート４を介して電荷転送部５に読み出され、さらに該電荷転送部５にて転送されるようになっている。
また、シリコン基板２の表面部には、熱酸化法やＣＶＤ法等によって形成されたＳｉＯ₂からなる絶縁膜７が設けられている。なお、この絶縁膜７についてはＳｉＯ₂膜からなる単層膜でなく、ＳｉＯ₂膜−ＳｉＮ膜−ＳｉＯ₂膜の三層からなるいわゆるＯＮＯ構造の積層膜としてもよい。
【００１５】
絶縁膜７の上には、前記電荷転送部５の略直上位置に第１ポリシリコンからなる転送電極８が形成されており、さらに転送電極８とは一部が重なり合う状態で、第２ポリシリコンからなる別の転送電極（図示略）が形成されている。これら転送電極８の表面上、すなわちその上面および側面上には、該転送電極８を覆い、さらに転送電極８、８間に臨む受光センサ部３上の絶縁膜７を覆ってＳｉＯ₂からなる層間絶縁膜９が形成されている。
【００１６】
この層間膜９の上には、前記転送電極８を覆った状態でアルミニウム（Ａｌ）やタングステン（Ｗ）等からなる遮光膜１０が形成されている。この遮光膜１０は、スミアを抑えるため受光センサ部３の直上にまで張り出してなる張り出し部１０ａを形成したもので、受光センサ部３の直上部分の大部分を外側に臨ませた状態で、すなわち受光センサ部３の直上に前記張り出し部１０ａで囲った状態に矩形の開口部１１を形成したものである。
【００１７】
この遮光膜１０上には、該遮光膜１０を覆ってＢＰＳＧ（ホウ素リンシリケートガラス）や高密度プラズマ−ＳｉＯ₂（ＨＤＰ−ＳｉＯ₂）等の、屈折率が約１．４５のＳｉＯ₂系材料からなる平坦化膜１２が形成されている。この平坦化膜１２は、受光センサ部３の直上位置において孔部１３を形成したものである。孔部１３は、遮光膜１０の開口部１１に連通し、その内面が開口部１１の内面に略面一となるようにして形成されたものである。
【００１８】
また、孔部１３と開口部１１との内面上には、該内面を覆って前記平坦化膜１２より屈折率が大きい第１の透明膜１４が設けられている。この第１の透明膜１４は、本例ではプラズマＣＶＤ法による窒化ケイ素膜（以下、Ｐ−ＳｉＮ膜と記す）からなるもので、その屈折率が約２．０のものである。したがって、孔部１３の内面部においては、前記平坦化膜１２と第１の透明膜１４との界面で大きな屈折率差があり、これによって該界面で大きな屈折が起こるようになっている。
【００１９】
具体的には、第１の透明膜１４に入射し、そのまま該第１の透明膜１４と平坦化膜１２との間の界面に到った光は、その入射角θ₁、すなわち該入射光と前記界面との法線とのなす角θ₁が４６．５°より大きい角度である場合に、入射光は該界面で全反射するようになっている。
【００２０】
つまり、次式に示されるスネルの法則において、
ｎ₁・ｓｉｎθ₁＝ｎ₂・ｓｉｎθ₂ （スネルの法則）
ｎ₁を第１の透明膜１４の屈折率（２．０）とし、ｎ₂を平坦化膜１２の屈折率（１．４５）とし、屈折角θ₂が９０°を越えると光が全反射になるとすれば、θ₂に９０°を代入し、さらにｎ₁＝２．０、ｎ₂＝１．４５とすることにより、
２．０×ｓｉｎθ₁＝１．４５×ｓｉｎ９０°となり、
ｓｉｎ９０°＝１であることから、ｓｉｎθ₁＝１．４５／２．０となり、
これから全反射するための臨界的な角度であるθ₁＝４６．５°が求まるのである。
【００２１】
また、孔部１３と開口部１１とにおける、前記第１の透明膜１４の内面上には、該内面を覆って第１の透明膜１４より屈折率が小さい第２の透明膜１５が設けられている。この第２の透明膜１５は、本例ではプラズマＣＶＤ法による酸化窒化ケイ素膜（以下、Ｐ−ＳｉＯＮ膜と記す）からなるもので、その屈折率が約１．８に調整されたものである。
さらに、この第２の透明膜１５の内面上には、該内面を覆い、かつ孔部１３および開口部１１を埋め込んだ状態に第３の透明膜１６が設けられている。この第３の透明膜１６も、本例ではプラズマＣＶＤ法による酸化窒化ケイ素膜（以下、Ｐ−ＳｉＯＮ膜と記す）からなるもので、この第３の透明膜１６ではその屈折率が約１．６に調整されたものとなっている。
【００２２】
ここで、Ｐ−ＳｉＯＮ膜の屈折率の調整については、その原料ガスであるＳｉＨ₄、ＮＨ₃、Ｎ₂Ｏの流量比を適宜に調整することによって行う。すなわち、ＳｉＨ₄を基準とした場合に、ＮＨ₃の流量比を増やすと屈折率が大きくなり、Ｎ₂Ｏの流量比を増やすと屈折率が小さくなる。これは、原料中のＮＨ₃が増えると得られるＰ−ＳｉＯＮ中のＳｉ−Ｎボンドが増え、一方原料中のＮ₂Ｏが増えると得られるＰ−ＳｉＯＮ中のＳｉ−Ｏボンドが増えるからである。
したがって、予めこれら原料ガスの流量比と得られるＰ−ＳｉＯＮの屈折率との関係を実験やシミュレーションによって求めておき、第２の透明膜１５、第３の透明膜１６の形成の際には、所望する屈折率に応じてその条件を適宜に選択すればよいのである。
【００２３】
このような第２の透明膜１５、第３の透明膜１６にあっては、その屈折率が第１の透明膜１４（ｎ＝２．０）、第２の透明膜１５（ｎ＝１．８）、第３の透明膜１６（ｎ＝１．６）の順に少しずつ小さくなることから、第１の透明膜１４と第２の透明膜１５との界面、第２の透明膜１５と第３の透明膜１６との界面でいずれも各膜の屈折率差によって屈折が起こるようになっている。
すなわち、第３の透明膜１６に入射した光が第２の透明膜１５に入り、また第２の透明膜１５に入射した光が第１の透明膜１４に入る場合には、前記のスネルの法則により各界面で孔部１３の内面側あるいは開口部１１の内面側に屈折し、一方、第２の透明膜１５に入射した光が第３の透明膜１６に入り、また第１の透明膜１４に入射した光が第２の透明膜１５に入る場合には、各界面で開口部１１の中央部側に屈折する。
【００２４】
なお、第１の透明膜１４、第２の透明膜１５、第３の透明膜１６の膜厚については、特に限定されることはないものの、孔部１３、開口部１１の内寸が数μｍ程度とされることから、それぞれ３００μｍ〜５００μｍ程度とするのが好ましい。これは、３００μｍ未満であると膜質の均一性が損なわれるおそれがあり、一方、５００μｍを超えると膜厚にムラが生じるおそれがあるからであり、このように膜質や膜厚が不均一になると、画素間における感度ムラが生じて感度特性が低下してしまうおそれがあるからである。
【００２５】
平坦化膜１２上には、孔部１３および開口部１１内に形成された第１の透明膜１４、第２の透明膜１５、第３の透明膜１６を覆った状態にＰ−ＳｉＮ等からなるパッシベーション膜１７が設けられている。
さらに、このパッシベーション膜１７上には樹脂等からなるカラーフィルタ層１８が形成されており、このカラーフィルタ層１８の上には凸状の透明樹脂等からなるオンチップレンズ１９が形成されている。このオンチップレンズ１９は、屈折率が１．５〜１．６程度の樹脂等の材料によって形成されたもので、入射光を孔部１３内に導くことによってこれを受光センサ部３上に入射させるためのものである。
【００２６】
このような構成の固体撮像素子１を作製するには、図２（ａ）に示すように従来と同様の手法により転送電極８までを形成し、さらにこれを覆って層間絶縁膜９を形成した後、遮光膜１０形成のための遮光材料膜１９を形成する。なお、この遮光材料膜１９については、固体撮像素子１の周辺回路における配線と同一の層として形成することも可能である。
次いで、平坦化膜１２の材料としてＢＰＳＧを、ＣＶＤ法等により図２（ｂ）に示すように遮光材料膜２０を覆った状態に堆積して平坦化層２１を形成し、さらに予め設定した条件でリフロー処理（熱処理）することにより、転送電極８、８等によって形成された凹凸を平坦化する。
【００２７】
次いで、図２（ｃ）に示すように平坦化膜１４上にレジストパターン２２を公知のレジスト技術、リソグラフィー技術によって形成する。続いて、図３（ａ）に示すようにこのレジストパターン２２をマスクにして平坦化層２１、遮光材料膜２０をエッチングし、平坦化層２１に孔部１３を形成して該平坦化層２１を平坦化膜１２とするとともに、遮光材料膜２０に開口部１１を形成して該遮光材料膜２０を遮光膜１０とする。
ここで、平坦化層２１、遮光材料膜２０のエッチングについては、同一のレジストパターン２２を用い、また同一のエッチャントを用いて行う必要はなく、例えば平坦化層２１と遮光材料膜２０とを別のエッチャントで、あるいは別のレジストパターンで形成してもよい。すなわち、本発明において平坦化層２１と遮光材料膜２０とのエッチングについては、これらを同一の条件で連続的に行っても、また異なる条件で非連続的に行ってもよく、あくまで孔部１３と開口部１１との内面が略面一となるような条件であれば特に限定されることはないのである。
【００２８】
このようにして孔部１３と開口部１１とを形成したら、図３（ｂ）に示すようにこれらの内面を覆った状態に屈折率が約２．０のＰ−ＳｉＮ膜２３を所定厚に形成し、続いて該Ｐ−ＳｉＮ膜２３の内面を覆った状態に屈折率が約１．８のＰ−ＳｉＯＮ膜２４を所定厚に形成し、さらに該Ｐ−ＳｉＯＮ膜２４の内面を覆った状態に屈折率が約１．６のＰ−ＳｉＯＮ膜２５を孔部１３、開口部１１を埋め込んだ状態に形成する。
なお、Ｐ−ＳｉＯＮ膜２４、２５の屈折率の調整については、前述したようにその原料ガスであるＳｉＨ₄、ＮＨ₃、Ｎ₂Ｏの流量比を適宜に調整することによって行う。
【００２９】
次いで、図３（ｃ）に示すように形成したＰ−ＳｉＯＮ膜２５、Ｐ−ＳｉＯＮ膜２４、Ｐ−ＳｉＮ膜２３の、平坦化膜１２上に形成された部分をエッチバック法あるいはＣＭＰ法（化学機械研磨法）によって除去し、これによって孔部１３内、および開口部１１内にのみ各膜を残してこの残した部分を第３の透明膜１６、第２の透明膜１５、第１の透明膜１４とする。
【００３０】
次いで、図１に示したようにＰ−ＳｉＮ膜からなるパッシベーション膜１７を形成し、さらに染色法やカラーレジスト塗布によってカラーフィルタ層１８を形成し、その後、オンチップレンズ１９を形成し、固体撮像素子１を得る。ここで、オンチップレンズ１９の形成については、熱溶融性透明樹脂や常温無加熱でＣＶＤ可能な高密度ＳｉＮを堆積させ、さらにその上部にレジストを設けた後、このレジストを熱リフロー処理して所望の曲率を有する凸レンズ形状にし、さらにこれをマスクにして前記堆積層をエッチングし、レジストを除去してオンチップレンズ１９を得るといったエッチバック転写等が用いられる。
【００３１】
このようにして得られた固体撮像素子１にあっては、オンチップレンズ１９で集光された光のうち受光センサ部３の表面にほぼ垂直に入射した光が、カラーフィルタ層１８、パッシベーション膜１７を透過して孔部１３内の第３の透明膜１６、第２の透明膜１５、または第１の透明膜１４に入射し、さらに開口部１１内を通って層間膜９、絶縁膜７を透過して受光センサ部３に到り、ここで光電変換がなす。
【００３２】
また、オンチップレンズ１９で集光された光のうち受光センサ部３の表面に対して斜めに入射した光は、第３の透明膜１６と第２の透明膜１５との界面、第２の透明膜１５と第１の透明膜１４との界面で前述したように屈折する。そして、これら界面で屈折した光のうち第１の透明膜１４と平坦化膜１２との界面に到った光は、特に該界面の法線とのなす入射角が所定角を超えている場合に全反射し、再度孔部１３あるいは開口部１１の中央部に戻されてそのまま受光センサ部３に入射する。
また、オンチップレンズ１９で集光され、受光センサ部３の表面に対して斜めに入射した光のうち第１の透明膜１４と遮光膜１０の開口部１１との界面に到った光は、該開口部１１の内面で全反射して開口部１１内に戻され、受光センサ部３上に入射する。
【００３３】
したがって、この固体撮像素子１にあっては、平坦化膜１２と第１の透明膜１４との界面での全反射、および第１の透明膜１４、第２の透明膜１５、第３の透明膜１６の各膜間での界面での屈折により、受光センサ部３の表面に対して斜めに入射した光をも効率よく受光センサ部３上に集光することができ、これにより感度向上を図ることができる。
また、このような固体撮像素子１の製造方法にあっては、図１に示した固体撮像素子１を容易にかつ確実に形成することができ、さらに、平坦化膜１２の膜厚を厚くすることにより、全反射をなす平坦化膜１２と第１の透明膜１４との界面の高さ（深さ）を容易に拡げることができ、これにより集光効率を一層高めることができる。
【００３４】
なお、前記実施形態例では、遮光膜１０を設けて転送電極８に光が入射するのを防止したが、本発明はこれに限定されることなく、平坦化膜１２と第１の透明膜１４との界面でここに入射した光を確実に全反射するようにして転送電極８に光が入射するのを防止してもよい。ここで、このように平坦化膜１２と第１の透明膜１４との界面で光を確実に全反射させるためには、例えばこれらの界面の高さ（深さ）を高く（深く）して全反射面を拡げたり、平坦化膜１２と第１の透明膜１４との屈折率差を大きくしたりすればよい。
このように遮光膜を設けることなく平坦化膜１２と第１の透明膜１４との界面で光を確実に全反射させるようにすれば、遮光膜を例えばアルミニウムで形成した場合に、このアルミニウムのグレインによって受光センサ部３…間でその開口形状や大きさが微妙に異なってしまい、乱反射成分も含めて受光センサ部間で微少な感度ムラが生じてしまうのを防止することができる。
【００３５】
また、前記実施形態例では、孔部１３および開口部１１内に第１の透明膜１４、第２の透明膜１５、第３の透明膜１６を形成したが、本発明はこれに限定されることなく、遮光膜１０を設けた場合には第１の透明膜１４のみを設けて該第１の透明膜１４と平坦化膜１２との界面で光を全反射させるようにすればよく、また遮光膜１０を設けない場合には第１の透明膜１４に加え少なくとも第２の透明膜１５を設けて第１の透明膜１４と平坦化膜１２との界面で光を確実に全反射させるようにすればよい。
【００３６】
【発明の効果】
以上説明したように本発明における第１の固体撮像素子は、第１の透明膜と平坦化膜との界面側に導かれた光を、第１の透明膜と平坦化膜との界面にて該第１の透明膜と平坦化膜との屈折率差により例えば全反射し、これによって孔部内に光を戻して受光センサ部上に入射させるようにしたものであるから、受光センサ部の表面に対して斜めに入射した光をも効率よく受光センサ部上に集光することができ、これにより感度向上を図ることができる。
【００３７】
本発明における第２の固体撮像素子は、第１の透明膜と平坦化膜との界面に到った光を該第１の透明膜と平坦化膜との屈折率差により例えば全反射し、また第１の透明膜と遮光膜の開口部との界面に到った光を該開口部の内面で全反射して開口部内に戻し、受光センサ部上に入射させるようにしたものであるから、受光センサ部の表面に対して斜めに入射した光をも効率よく受光センサ部上に集光することができ、これにより感度向上を図ることができる。
【００３８】
本発明における固体撮像素子の製造方法は、本発明における第２の固体撮像素子を容易にかつ確実に形成することができ、また、平坦化膜の膜厚を厚くすることにより、全反射をなす平坦化膜と第１の透明膜との界面の高さ（深さ）を容易に拡げて該界面による全反射率を高めることができる。
【図面の簡単な説明】
【図１】本発明の固体撮像素子の一実施形態例の概略構成を示す要部側断面図である。
【図２】（ａ）〜（ｃ）は図１に示した固体撮像素子の製造方法を工程順に説明するための要部側断面図である。
【図３】（ａ）〜（ｃ）は図１に示した固体撮像素子の製造方法を説明するための図であり、図２（ｃ）に続く工程を工程順に説明するための要部側断面図である。
【符号の説明】
１…固体撮像素子、２…シリコン基板（基体）、３…受光センサ部、５…電荷転送部、７…絶縁膜、８…転送電極、１０…遮光膜、１１…開口部、１２…平坦化膜、１３…孔部、１４…第１の透明膜、１５…第２の透明膜、１６…第３の透明膜、２０…遮光材料膜[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a solid-state imaging device that improves light collection efficiency to a light receiving sensor unit and improves sensitivity characteristics, and a method for manufacturing the same.
[0002]
[Prior art]
With the miniaturization of solid-state imaging devices, it is essential to improve the sensitivity especially for devices smaller than 1/4 "380,000 pixels. A device such as a lens is provided to increase the light collection efficiency.
[0003]
However, in recent years, although further improvement in light collection efficiency is desired along with the downsizing and high sensitivity of devices, the light collection effect by the above-described on-chip lens is almost approaching the limit. Development of another new technology is desired.
[0004]
As a technique corresponding to such a demand, a technique for providing an in-layer lens in a state of being used together with an on-chip lens has been proposed in part. This intra-layer lens is a lens formed in the interlayer film immediately above the light-receiving portion that performs photoelectric conversion. Like the on-chip lens, the intra-layer lens transmits light incident on the intra-layer lens on the upper surface side or lower surface of the intra-layer lens. The light is refracted at the side interface and guided to the light receiving portion. Therefore, by using such an interlayer lens together with the on-chip lens, it is possible to condense the incident light that has been collected by the on-chip lens again by the intra-layer lens. The light collection efficiency can be further increased.
[0005]
[Problems to be solved by the invention]
However, most of the conventionally proposed intralayer lenses are concave lenses. When forming this, a film having a reflow shape such as BPSG (boron phosphorus silicate glass) is formed on the light shielding film, and the transfer electrode is formed. In general, a process in which a high refractive index material is embedded in a recess formed immediately above the light receiving portion and the embedded high refractive index material is used as an in-layer lens is generally employed.
In this process, the shape of the in-layer lens is determined by the shape of the reflow film. Therefore, it is difficult to obtain a desired shape, that is, an optimum shape for condensing light. However, it is still difficult to obtain sufficiently high light collection efficiency.
[0006]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a solid-state imaging device having a condensing function in place of an interlayer lens, thereby improving condensing efficiency, and a method for manufacturing the same. There is to do.
[0007]
[Means for Solving the Problems]
In the first solid-state imaging device according to the present invention, a light receiving sensor unit that is provided on a surface layer portion of the substrate and performs photoelectric conversion, a charge transfer unit that transfers signal charges read from the light receiving sensor unit, and the substrate And a transfer electrode provided via an insulating film at a position almost directly above the charge transfer portion, and covers the transfer electrode and forms a hole in a part of the position directly above the light receiving sensor portion. In this state, a planarizing film is provided, and a first transparent film having a refractive index larger than that of the planarizing film is provided on the inner surface of the hole portion, and further on the inner surface of the first transparent film. The above-described means for solving the above-mentioned problems is that a second transparent film having a refractive index smaller than that of the first transparent film is provided to cover the inner surface.
[0008]
According to this solid-state imaging device, the first transparent film is provided on the inner surface of the hole formed in the planarizing film, the second transparent film is provided on the inner surface of the first transparent film, and the first transparent film is further provided. Since the second transparent film is provided on the inner surface of the transparent film, the second transparent film and the first transparent film are incident obliquely to the surface of the light receiving sensor portion of the light incident in the hole portion. The light reaching the interface is refracted at the interface due to the difference in refractive index between the second transparent film and the first transparent film, and is guided to the interface side between the first transparent film and the planarizing film. Then, the light guided to the interface side between the first transparent film and the planarizing film is refracted by the first transparent film and the planarizing film at the interface between the first transparent film and the planarizing film. For example, the light is totally reflected due to the rate difference, and is thereby returned into the hole and incident on the light receiving sensor.
[0009]
In the second solid-state imaging device according to the present invention, a light receiving sensor unit that is provided on a surface layer portion of the substrate and performs photoelectric conversion, a charge transfer unit that transfers a signal charge read from the light receiving sensor unit, and the substrate A transfer electrode provided via an insulating film at a position almost directly above the charge transfer portion, and a state where the transfer electrode is covered and an opening is formed at a part of the position directly above the light receiving sensor portion. A planarizing film in a state in which a hole that covers the light shielding film and communicates with the opening is formed so that an inner surface thereof is substantially flush with an inner surface of the opening. The means for solving the above-mentioned problems is that a first transparent film having a refractive index larger than that of the planarizing film is provided on the inner surfaces of the hole and the opening.
[0010]
According to this solid-state imaging device, the flattening film is provided in a state in which the hole that covers the light shielding film and that communicates with the opening is formed so that the inner surface thereof is substantially flush with the inner surface of the opening. Since the first transparent film is provided on the inner surfaces of the hole and the opening, the light incident on the hole is obliquely incident on the surface of the light receiving sensor part and guided to the first transparent film. The light reaching the interface between the first transparent film and the planarizing film is totally reflected, for example, due to the difference in refractive index between the first transparent film and the planarizing film, and between the first transparent film and the light shielding film. The light that reaches the interface with the opening is totally reflected by the inner surface of the opening and returned into the opening, and is incident on the light receiving sensor.
[0011]
In the method for manufacturing a solid-state imaging device according to the present invention, a light receiving sensor unit that is provided on a surface layer portion of the substrate and performs photoelectric conversion, a charge transfer unit that transfers signal charges read from the light receiving sensor unit, A transfer electrode provided via an insulating film at a position almost directly above the charge transfer portion, and a state where the transfer electrode is covered and an opening is formed at a part of the position directly above the light receiving sensor portion. When manufacturing a solid-state imaging device including a light shielding film, a light shielding material film is formed so as to cover the transfer electrode, and then a planarizing film material is formed on the light shielding material film, and the flat A hole formed in the flattening film by flattening the flattening film material to form a flattening film and then etching the flattening film and the light-shielding film located immediately above a part of the light receiving sensor unit The inner surface of the opening and the inner surface of the opening formed in the light shielding film Are formed so that the holes of the planarizing film and the opening of the light shielding film are substantially flush with each other, and then the inner surface of the hole and the opening is covered with the inner surface of the planarizing film so that the refractive index is higher than that of the planarizing film. Forming a large first transparent film is a means for solving the above-described problems.
[0012]
According to this method for manufacturing a solid-state imaging device, the inner surface of the hole formed in the planarization film and the inner surface of the opening formed in the light shielding film are etched by etching the planarization film and the light shielding film. Since the hole portion of the planarizing film and the opening portion of the light shielding film are formed so as to be uniform, and then the first transparent film having a higher refractive index than the planarizing film is formed on the inner surface of the hole portion and the opening portion. Thus, the obtained solid-state imaging device has the first transparent film provided on the inner surfaces of the hole and the opening. Therefore, in this solid-state imaging device, the light incident on the hole is not exposed to the surface of the light receiving sensor unit. Light that is incident obliquely and is guided to the first transparent film and reaches the interface between the first transparent film and the planarizing film is caused by a difference in refractive index between the first transparent film and the planarizing film, for example. The light that totally reflects and reaches the interface between the first transparent film and the opening of the light shielding film is the opening. Back into the opening is totally reflected by the inner surface, it will be incident on the light receiving sensor portion.
Further, by increasing the film thickness of the planarizing film, it is possible to easily increase the height (depth) of the interface between the planarizing film that makes total reflection and the first transparent film.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail below.
FIG. 1 is a diagram showing an embodiment of a solid-state imaging device according to the present invention. In FIG. 1, reference numeral 1 denotes a solid-state imaging device, and 2 denotes a silicon substrate (substrate). As shown in FIG. 1, the silicon substrate 2 has a light receiving portion (not shown) that performs photoelectric conversion on the surface layer portion, and further a hole accumulation portion (not shown) is formed on the light receiving portion. A light receiving sensor unit 3 having a HAD (Holl Accumulation Diode) structure is formed from the light receiving unit and the hole accumulating unit.
[0014]
A charge transfer unit 5 is formed on one side of the light receiving sensor unit 3 via a read gate 4, and another charge transfer unit 5 is formed on the other side via a channel stop 6. The signal charge obtained by photoelectric conversion by the light receiving sensor unit 3 with such a configuration is read out to the charge transfer unit 5 through the read gate 4 and further transferred by the charge transfer unit 5. It has become.
Further, an insulating film 7 made of SiO ₂ formed by a thermal oxidation method, a CVD method or the like is provided on the surface portion of the silicon substrate 2. Instead a single layer film made of SiO ₂ film for the insulating film 7, or a stacked film of a so-called ONO structure composed of three layers of SiO ₂ film -SiN film -SiO ₂ film.
[0015]
A transfer electrode 8 made of the first polysilicon is formed on the insulating film 7 at a position almost immediately above the charge transfer portion 5, and the second polysilicon is partially overlapped with the transfer electrode 8. Another transfer electrode (not shown) is formed. On the surface of the transfer electrodes 8, that is, on its upper surface and side surfaces, covering the transfer electrodes 8, comprising further a SiO ₂ covering the insulating film 7 on the light-receiving sensor section 3 facing between the transfer electrodes 8 and 8 layers An insulating film 9 is formed.
[0016]
A light shielding film 10 made of aluminum (Al), tungsten (W), or the like is formed on the interlayer film 9 so as to cover the transfer electrode 8. This light-shielding film 10 is formed with an overhanging portion 10a that projects to the position directly above the light receiving sensor portion 3 in order to suppress smear, and in a state where most of the portion directly above the light receiving sensor portion 3 faces outward, that is, A rectangular opening 11 is formed immediately above the light receiving sensor 3 in a state surrounded by the protruding portion 10a.
[0017]
On the light shielding film 10, BPSG (boron phosphorus silicate glass) covering the light shielding film 10 and the high-density plasma _{_{-SiO 2 (HDP-SiO 2)}} SiO 2 system, a refractive index of about 1.45 like material A planarizing film 12 made of is formed. The planarizing film 12 is formed with a hole 13 at a position immediately above the light receiving sensor unit 3. The hole 13 communicates with the opening 11 of the light shielding film 10 and is formed so that the inner surface thereof is substantially flush with the inner surface of the opening 11.
[0018]
A first transparent film 14 having a refractive index larger than that of the planarizing film 12 is provided on the inner surfaces of the hole 13 and the opening 11. In this example, the first transparent film 14 is made of a silicon nitride film (hereinafter referred to as a P-SiN film) formed by a plasma CVD method, and has a refractive index of about 2.0. Therefore, in the inner surface portion of the hole portion 13, there is a large refractive index difference at the interface between the planarizing film 12 and the first transparent film 14, thereby causing large refraction at the interface.
[0019]
Specifically, the light that enters the first transparent film 14 and reaches the interface between the first transparent film 14 and the planarizing film 12 as it is is the incident angle θ ₁ , that is, the incident light. When the angle θ ₁ formed by the normal to the interface is larger than 46.5 °, the incident light is totally reflected at the interface.
[0020]
In other words, in Snell's law expressed by
n ₁ · sin θ ₁ = n ₂ · sin θ ₂ (Snell's law)
n ₁ is the refractive index (2.0) of the first transparent film 14, n ₂ is the refractive index (1.45) of the planarizing film 12, and light is totally reflected when the refraction angle θ ₂ exceeds 90 °. Then, by substituting 90 ° into θ ₂ and further setting n ₁ = 2.0 and n ₂ = 1.45,
2.0 × sin θ ₁ = 1.45 × sin 90 °,
Since sin 90 ° = 1, sin θ ₁ = 1.45 / 2.0,
From this, θ ₁ = 46.5 °, which is a critical angle for total reflection, is obtained.
[0021]
A second transparent film 15 having a refractive index smaller than that of the first transparent film 14 is provided on the inner surface of the first transparent film 14 in the hole 13 and the opening 11 so as to cover the inner surface. ing. In this example, the second transparent film 15 is made of a silicon oxynitride film (hereinafter referred to as a P-SiON film) formed by a plasma CVD method, and its refractive index is adjusted to about 1.8. .
Further, a third transparent film 16 is provided on the inner surface of the second transparent film 15 so as to cover the inner surface and fill the hole 13 and the opening 11. The third transparent film 16 is also composed of a silicon oxynitride film (hereinafter referred to as a P-SiON film) formed by plasma CVD in this example, and the refractive index of the third transparent film 16 is about 1. It has been adjusted to 6.
[0022]
Here, the adjustment of the refractive index of the P-SiON film is performed by appropriately adjusting the flow ratio of SiH ₄ , NH ₃ , and N ₂ O that are the source gases. That is, when SiH ₄ is used as a reference, increasing the NH ₃ flow rate ratio increases the refractive index, and increasing the N ₂ O flow rate ratio decreases the refractive index. This is because when NH ₃ in the raw material increases, the number of Si—N bonds in the obtained P—SiON increases, while when the amount of N ₂ O in the raw material increases, the number of Si—O bonds in the obtained P—SiON increases. is there.
Therefore, the relationship between the flow rate ratio of these source gases and the refractive index of P-SiON obtained is obtained in advance by experiments and simulations, and when forming the second transparent film 15 and the third transparent film 16, The conditions may be appropriately selected according to the desired refractive index.
[0023]
In the second transparent film 15 and the third transparent film 16 as described above, the refractive indexes thereof are the first transparent film 14 (n = 2.0) and the second transparent film 15 (n = 1. 8) Since the third transparent film 16 (n = 1.6) gradually decreases in order, the interface between the first transparent film 14 and the second transparent film 15, the second transparent film 15 and the second transparent film 15 The refraction is caused by the difference in the refractive index of each film at the interface with the three transparent films 16.
That is, when the light incident on the third transparent film 16 enters the second transparent film 15 and the light incident on the second transparent film 15 enters the first transparent film 14, The light is refracted to the inner surface side of the hole 13 or the inner surface side of the opening portion 11 at each interface according to the law, while the light incident on the second transparent film 15 enters the third transparent film 16 and also enters the first transparent film. When the light incident on 14 enters the second transparent film 15, it is refracted toward the center of the opening 11 at each interface.
[0024]
The film thicknesses of the first transparent film 14, the second transparent film 15, and the third transparent film 16 are not particularly limited, but the inner dimensions of the hole 13 and the opening 11 are several μm. Therefore, it is preferable that the thickness is about 300 μm to 500 μm. This is because if the thickness is less than 300 μm, the uniformity of the film quality may be impaired. On the other hand, if the thickness exceeds 500 μm, the film thickness may be uneven. This is because there is a possibility that sensitivity unevenness occurs between the pixels and the sensitivity characteristics deteriorate.
[0025]
On the planarizing film 12, the first transparent film 14, the second transparent film 15, and the third transparent film 16 formed in the hole 13 and the opening 11 are covered with P-SiN or the like. A passivation film 17 is provided.
Further, a color filter layer 18 made of a resin or the like is formed on the passivation film 17, and an on-chip lens 19 made of a convex transparent resin or the like is formed on the color filter layer 18. The on-chip lens 19 is formed of a material such as a resin having a refractive index of about 1.5 to 1.6. The on-chip lens 19 is incident on the light receiving sensor unit 3 by guiding incident light into the hole 13. It is for making it happen.
[0026]
In order to fabricate the solid-state imaging device 1 having such a configuration, as shown in FIG. 2A, up to the transfer electrode 8 was formed by the same method as in the prior art, and an interlayer insulating film 9 was formed covering this. Thereafter, a light shielding material film 19 for forming the light shielding film 10 is formed. The light shielding material film 19 can be formed as the same layer as the wiring in the peripheral circuit of the solid-state imaging device 1.
Next, BPSG is deposited as a material of the planarizing film 12 by a CVD method or the like so as to cover the light shielding material film 20 as shown in FIG. The unevenness formed by the transfer electrodes 8 and 8 is flattened by reflow treatment (heat treatment).
[0027]
Next, as shown in FIG. 2C, a resist pattern 22 is formed on the planarizing film 14 by a known resist technique and lithography technique. Subsequently, as shown in FIG. 3A, the planarization layer 21 and the light shielding material film 20 are etched using the resist pattern 22 as a mask to form a hole 13 in the planarization layer 21 to form the planarization layer 21. Is formed as a planarizing film 12, and an opening 11 is formed in the light shielding material film 20 to make the light shielding material film 20 a light shielding film 10.
Here, the planarization layer 21 and the light shielding material film 20 need not be etched using the same resist pattern 22 and the same etchant. For example, the planarization layer 21 and the light shielding material film 20 are separated from each other. The etchant may be formed of another resist pattern. That is, in the present invention, the etching of the planarizing layer 21 and the light shielding material film 20 may be performed continuously under the same conditions or discontinuously under different conditions. There is no particular limitation as long as the inner surfaces of the opening 11 and the opening 11 are substantially flush with each other.
[0028]
When the hole 13 and the opening 11 are formed in this way, the P-SiN film 23 having a refractive index of about 2.0 is formed to a predetermined thickness so as to cover the inner surfaces thereof as shown in FIG. Then, a P-SiON film 24 having a refractive index of about 1.8 is formed to a predetermined thickness so as to cover the inner surface of the P-SiN film 23, and further, the inner surface of the P-SiON film 24 is covered. A P-SiON film 25 having a refractive index of about 1.6 is formed in a state where the hole 13 and the opening 11 are embedded.
Note that the refractive indexes of the P-SiON films 24 and 25 are adjusted by appropriately adjusting the flow ratio of SiH ₄ , NH ₃ , and N ₂ O that are the source gases as described above.
[0029]
Next, portions of the P-SiON film 25, the P-SiON film 24, and the P-SiN film 23 formed on the planarizing film 12 as shown in FIG. 3C are etched back or CMP ( Chemical mechanical polishing method), thereby leaving each film only in the hole 13 and the opening 11, and leaving the remaining portions in the third transparent film 16, the second transparent film 15, and the first The transparent film 14 is used.
[0030]
Next, as shown in FIG. 1, a passivation film 17 made of a P-SiN film is formed, and further a color filter layer 18 is formed by a dyeing method or a color resist coating, and then an on-chip lens 19 is formed, and solid-state imaging is performed. Element 1 is obtained. Here, the on-chip lens 19 is formed by depositing a heat-meltable transparent resin or high-density SiN that can be CVD without heating at room temperature, and further providing a resist on the upper portion, and then performing a thermal reflow treatment on the resist. Etch-back transfer or the like is used in which a convex lens shape having a desired curvature is formed, and the deposited layer is etched using this as a mask, and the resist is removed to obtain the on-chip lens 19.
[0031]
In the solid-state imaging device 1 obtained in this way, the light incident on the surface of the light-receiving sensor unit 3 out of the light condensed by the on-chip lens 19 is the color filter layer 18 and the passivation film. 17, enters the third transparent film 16, the second transparent film 15, or the first transparent film 14 in the hole portion 13, and further passes through the opening portion 11 to pass through the interlayer film 9 and the insulating film 7. And reaches the light receiving sensor unit 3 where photoelectric conversion is performed.
[0032]
In addition, the light incident on the surface of the light receiving sensor unit 3 among the light condensed by the on-chip lens 19 is incident on the interface between the third transparent film 16 and the second transparent film 15, the second As described above, the light is refracted at the interface between the transparent film 15 and the first transparent film 14. Of the light refracted at these interfaces, the light that reaches the interface between the first transparent film 14 and the planarizing film 12 particularly has an incident angle with the normal of the interface exceeding a predetermined angle. Then, the light is totally reflected again, returned to the center of the hole 13 or the opening 11, and is incident on the light receiving sensor 3 as it is.
In addition, the light that has been collected by the on-chip lens 19 and incident on the surface of the light receiving sensor unit 3 obliquely reaches the interface between the first transparent film 14 and the opening 11 of the light shielding film 10. The light is totally reflected from the inner surface of the opening 11 and returned to the opening 11 to enter the light-receiving sensor unit 3.
[0033]
Therefore, in this solid-state imaging device 1, total reflection at the interface between the planarizing film 12 and the first transparent film 14, and the first transparent film 14, the second transparent film 15, and the third transparent film. By refraction at the interface between the films 16, light incident obliquely on the surface of the light receiving sensor unit 3 can be efficiently condensed on the light receiving sensor unit 3, thereby improving sensitivity. Can be planned.
Further, in such a manufacturing method of the solid-state imaging device 1, the solid-state imaging device 1 shown in FIG. 1 can be easily and reliably formed, and the thickness of the planarizing film 12 is increased. As a result, the height (depth) of the interface between the planarizing film 12 and the first transparent film 14 that makes total reflection can be easily expanded, and the light collection efficiency can be further increased.
[0034]
In the embodiment, the light shielding film 10 is provided to prevent light from entering the transfer electrode 8. However, the present invention is not limited to this, and the planarizing film 12 and the first transparent film 14 are not limited thereto. It is also possible to prevent the light incident on the transfer electrode 8 from entering the transfer electrode 8 by surely totally reflecting the light incident here at the interface. Here, in order to surely totally reflect light at the interface between the planarizing film 12 and the first transparent film 14 in this way, for example, the height (depth) of these interfaces is increased (deep). What is necessary is just to enlarge a total reflection surface or enlarge the refractive index difference of the planarization film | membrane 12 and the 1st transparent film 14.
Thus, if light is reliably totally reflected at the interface between the planarizing film 12 and the first transparent film 14 without providing a light shielding film, when the light shielding film is formed of aluminum, for example, It can be prevented that the opening shape and size of the light receiving sensor portions 3 are slightly different due to the grains, and that slight sensitivity unevenness is generated between the light receiving sensor portions including the irregular reflection component.
[0035]
In the above embodiment, the first transparent film 14, the second transparent film 15, and the third transparent film 16 are formed in the hole 13 and the opening 11, but the present invention is limited to this. In the case where the light shielding film 10 is provided, only the first transparent film 14 may be provided so that the light is totally reflected at the interface between the first transparent film 14 and the planarizing film 12. When the light shielding film 10 is not provided, at least a second transparent film 15 is provided in addition to the first transparent film 14 so that light is reliably totally reflected at the interface between the first transparent film 14 and the planarizing film 12. You can do it.
[0036]
【The invention's effect】
As described above, in the first solid-state imaging device according to the present invention, light guided to the interface side between the first transparent film and the planarization film is transmitted at the interface between the first transparent film and the planarization film. For example, the first transparent film and the flattening film are totally reflected due to a difference in refractive index, thereby returning light into the hole and entering the light receiving sensor part. The light incident obliquely with respect to the light can be efficiently collected on the light receiving sensor unit, and thus the sensitivity can be improved.
[0037]
The second solid-state imaging device according to the present invention totally reflects, for example, light reaching the interface between the first transparent film and the planarizing film due to a difference in refractive index between the first transparent film and the planarizing film. Further, the light reaching the interface between the first transparent film and the opening of the light shielding film is totally reflected by the inner surface of the opening and returned into the opening, and is incident on the light receiving sensor. Also, light incident obliquely with respect to the surface of the light receiving sensor portion can be efficiently condensed on the light receiving sensor portion, thereby improving sensitivity.
[0038]
The manufacturing method of the solid-state imaging device according to the present invention can form the second solid-state imaging device according to the present invention easily and reliably, and makes the total reflection by increasing the thickness of the planarizing film. The height (depth) of the interface between the planarizing film and the first transparent film can be easily increased to increase the total reflectivity by the interface.
[Brief description of the drawings]
FIG. 1 is a side sectional view of an essential part showing a schematic configuration of an embodiment of a solid-state imaging device of the present invention.
FIGS. 2A to 2C are side cross-sectional views for explaining a manufacturing method of the solid-state imaging device shown in FIG.
FIGS. 3A to 3C are views for explaining a method of manufacturing the solid-state imaging device shown in FIG. 1, and a side of a main part for explaining steps subsequent to FIG. It is sectional drawing.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Solid-state image sensor, 2 ... Silicon substrate (base | substrate), 3 ... Light-receiving sensor part, 5 ... Charge transfer part, 7 ... Insulating film, 8 ... Transfer electrode, 10 ... Light shielding film, 11 ... Opening part, 12 ... Planarization Membrane, 13 ... hole, 14 ... first transparent film, 15 ... second transparent film, 16 ... third transparent film, 20 ... light shielding material film

Claims

Comprising a light receiving sensor portion for photoelectric conversion provided on the surface layer portion of the substrate ;
A planarizing film is provided in a state where a hole is formed in a part of the position directly above the light receiving sensor part ,
A first transparent film having a refractive index larger than that of the planarizing film is provided on the inner surface of the hole, covering the inner surface;
Furthermore, a second transparent film having a refractive index smaller than that of the first transparent film is provided on the inner surface of the first transparent film so as to cover the inner surface.

Comprising a light receiving sensor part for photoelectric conversion provided on the surface layer part of the base, and a transfer electrode provided on the base via an insulating film ;
A flattening film is provided in a state of covering the transfer electrode and forming a hole in a part of the position directly above the light receiving sensor part,
A first transparent film having a refractive index larger than that of the planarizing film is provided on the inner surface of the hole, covering the inner surface;
Furthermore, a second transparent film having a refractive index smaller than that of the first transparent film is provided on the inner surface of the first transparent film so as to cover the inner surface.

A light receiving sensor portion that is provided on the surface layer portion of the substrate and performs photoelectric conversion, and a light shielding film provided in a state in which an opening is formed in a part of the position immediately above the light receiving sensor portion ,
A flattening film is provided in a state of covering the light shielding film and forming a hole communicating with the opening so that the inner surface thereof is substantially flush with the inner surface of the opening,
A first transparent film having a refractive index larger than that of the planarizing film is provided on the inner surfaces of the hole and the opening;
A solid-state imaging device, wherein a second transparent film having a refractive index smaller than that of the first transparent film is provided on the inner surface of the first transparent film.

A light receiving sensor unit for photoelectric conversion provided on the surface layer of the base, a transfer electrode provided on the base via an insulating film , and a part of the position directly above the light receiving sensor that covers the transfer electrode A light shielding film provided in a state where the opening is formed,
A flattening film is provided in a state of covering the light shielding film and forming a hole communicating with the opening so that the inner surface thereof is substantially flush with the inner surface of the opening,
A first transparent film having a refractive index larger than that of the planarizing film is provided on the inner surfaces of the hole and the opening;
A solid-state imaging device, wherein a second transparent film having a refractive index smaller than that of the first transparent film is provided on the inner surface of the first transparent film.

Production of a solid-state imaging device comprising a light- receiving sensor portion that is provided on a surface layer portion of a substrate and performs photoelectric conversion, and a light-shielding film that is provided in a state where an opening is formed in a portion immediately above the light-receiving sensor portion A method,
Forming a light shielding material film on the substrate;
Forming a planarizing film material on the light shielding material film and planarizing the planarizing film material to form a planarizing film;
By etching the flattening film and the light shielding film located immediately above a part of the light receiving sensor part, an inner surface of a hole formed in the flattening film and an inner surface of an opening formed in the light shielding film are formed. Forming the holes of the planarization film and the opening of the light shielding film so as to be substantially flush with each other;
Forming a first transparent film having a refractive index larger than that of the planarizing film, covering the inner surface of the hole and the opening;
And a step of forming a second transparent film having a refractive index smaller than that of the first transparent film on the inner surface of the first transparent film so as to cover the inner surface. .

A light receiving sensor unit for photoelectric conversion provided on the surface layer of the base, a transfer electrode provided on the base via an insulating film , and a part of the position directly above the light receiving sensor that covers the transfer electrode A manufacturing method of a solid-state imaging device comprising a light shielding film provided in a state where an opening is formed,
Forming a light shielding material film in a state of covering the transfer electrode;
Forming a planarizing film material on the light shielding material film and planarizing the planarizing film material to form a planarizing film;
By etching the flattening film and the light shielding film located immediately above a part of the light receiving sensor part, an inner surface of a hole formed in the flattening film and an inner surface of an opening formed in the light shielding film are formed. Forming the holes of the planarization film and the opening of the light shielding film so as to be substantially flush with each other;
Forming a first transparent film having a refractive index larger than that of the planarizing film, covering the inner surface of the hole and the opening;
And a step of forming a second transparent film having a refractive index smaller than that of the first transparent film on the inner surface of the first transparent film so as to cover the inner surface. .