JP2013012518A - Solid state imaging device - Google Patents
Solid state imaging device Download PDFInfo
- Publication number
- JP2013012518A JP2013012518A JP2011142702A JP2011142702A JP2013012518A JP 2013012518 A JP2013012518 A JP 2013012518A JP 2011142702 A JP2011142702 A JP 2011142702A JP 2011142702 A JP2011142702 A JP 2011142702A JP 2013012518 A JP2013012518 A JP 2013012518A
- Authority
- JP
- Japan
- Prior art keywords
- microlens
- solid
- state imaging
- imaging device
- antireflection film
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Abstract
Description
本発明は、固体撮像素子に設けるマイクロレンズの高性能化に関する。 The present invention relates to enhancement of the performance of a microlens provided in a solid-state imaging device.
近年、撮像装置は画像の記録、通信、放送の内容の拡大に伴って広く用いられるようになっている。撮像装置として種々の形式のものが提案されているが、小型、軽量で高性能のものが安定して製造されるようになった固体撮像素子を組み込んだ撮像装置が、デジタルカメラやデジタルビデオとして普及してきている。 In recent years, imaging devices have been widely used with the expansion of the contents of image recording, communication, and broadcasting. Various types of image pickup devices have been proposed. An image pickup device incorporating a solid-state image pickup device that has been stably manufactured with a small size, light weight, and high performance can be used as a digital camera or digital video. It has become widespread.
固体撮像素子は、撮影対象物からの光学像を受け、入射した光を電気信号に変換する複数の光電変換素子を有する。光電変換素子の種類はＣＣＤ（電荷結合素子）タイプとＣＭＯＳ（相補型金属酸化物半導体）タイプとに大別される。また、光電変換素子の配列形態から、光電変換素子を1列に配置したリニアセンサー（ラインセンサー）と、光電変換素子を縦横に２次元的に配列させたエリアセンサー（面センサー）との２種類に大別される。いずれのセンサにおいても光電変換素子の数（画素数）が多いほど撮影された画像は精密になるので、近年は特に、大画素数の固体撮像素子を安価に製造する方法が検討されている。 The solid-state imaging device has a plurality of photoelectric conversion elements that receive an optical image from a subject and convert incident light into an electrical signal. The types of photoelectric conversion elements are roughly classified into CCD (charge coupled device) type and CMOS (complementary metal oxide semiconductor) type. In addition, there are two types of photoelectric conversion elements: linear sensors (line sensors) in which photoelectric conversion elements are arranged in a row, and area sensors (surface sensors) in which photoelectric conversion elements are two-dimensionally arranged vertically and horizontally. It is divided roughly into. In any of the sensors, as the number of photoelectric conversion elements (number of pixels) increases, the captured image becomes more precise. In recent years, in particular, a method for manufacturing a solid-state imaging element having a large number of pixels at low cost has been studied.
また、光電変換素子に入射する光の経路に特定の波長の光を透過する各種のカラーフィルタを設けることで、対象物の色情報を得ることを可能とした単板式のカラーセンサーとしてのカラー固体撮像素子も普及している。カラー固体撮像素子は、１個の光電変換素子に対応して特定の色の１画素を設けて、色分解した画像情報を集めることができる。カラーフィルタの色としては、赤色（Ｒ）、緑色（Ｇ）、青色（Ｂ）の３色からなる３原色系、あるいは、シアン色（Ｃ）、マゼンタ色（Ｍ）、イエロー色（Ｙ）からなる補色系が一般的であり、特に３原色系が多く使われている。 In addition, a color solid as a single-plate color sensor that can obtain color information of an object by providing various color filters that transmit light of a specific wavelength in the path of light incident on the photoelectric conversion element. Imaging devices are also widespread. The color solid-state imaging device can collect one color pixel corresponding to one photoelectric conversion device and collect color-separated image information. As the color of the color filter, three primary colors composed of three colors of red (R), green (G), and blue (B), cyan (C), magenta (M), and yellow (Y) are used. Complementary color systems are generally used, and in particular, the three primary color systems are often used.
カラーフィルタは、フォトリソグラフィー法を用いて形成することが主流となっている。すなわち、基板上に所定の色の感光性着色透明樹脂を塗布した後、所定のパターンを有する露光用フォトマスクを介して感光性着色透明樹脂にパターン露光、現像を行い、所定の部位に着色透明樹脂からなるカラーフィルタを形成する。また、基板上への感光性着色透明樹脂の塗布としては、回転塗布法を用いることが多い。すなわち、基板上に感光性着色透明樹脂を滴下した後、基板を回転することで滴下した感光性着色透明樹脂を基板上に均一に塗り広げる方法である。 The color filter is mainly formed using a photolithography method. That is, after applying a photosensitive colored transparent resin of a predetermined color on a substrate, pattern exposure and development are performed on the photosensitive colored transparent resin through an exposure photomask having a predetermined pattern, and a predetermined transparent portion is colored transparent. A color filter made of resin is formed. In addition, as the application of the photosensitive colored transparent resin on the substrate, a spin coating method is often used. That is, after the photosensitive colored transparent resin is dropped on the substrate, the photosensitive colored transparent resin dropped is uniformly spread on the substrate by rotating the substrate.
固体撮像素子に要求される性能で重要な課題の一つに、入射する光への感度を向上させることが挙げられる。小型化した固体撮像素子で撮影した画像の情報量を多くするためには受光部となる光電変換素子を微細化して高集積化する必要がある。しかし、光電変換素子を微細化した場合、各光電変換素子の面積が小さくなり、受光部として利用できる面積割合も減るので、光を取り込む面積が小さくなるため、光電変換素子の受光部に取り込める光の量が少なくなり、実効的な感度は低下する。 One of the important issues in performance required for a solid-state imaging device is to improve the sensitivity to incident light. In order to increase the amount of information of an image photographed with a miniaturized solid-state imaging device, it is necessary to miniaturize and highly integrate a photoelectric conversion device serving as a light receiving unit. However, when the photoelectric conversion element is miniaturized, the area of each photoelectric conversion element is reduced, and the area ratio that can be used as the light receiving unit is also reduced. And the effective sensitivity decreases.
このような、微細化した固体撮像素子の感度の低下を防止するための手段として、光電変換素子の受光部に効率良く光を取り込むために、対象物から入射される光を集光して光電変換素子の受光部に導くマイクロレンズを光電変換素子上に形成する技術が提案されている。マイクロレンズで光を集光して光電変換素子の受光部に導くことで、受光部の見かけ上の開口率を大きくすることが可能になり、固体撮像素子の感度の向上が可能になる。マイクロレンズの形成方法としては、マイクロレンズの素材となるアクリル系感光性樹脂
をフォトリソグラフィー法により選択的にパターン形成した後に、材料の熱リフロー性を利用してレンズ形状を作るフローレンズタイプ（特許文献１参照）や、マイクロレンズの素材となるアクリル透明樹脂の平坦層の上に、アルカリ可溶性と感光性と熱フロー性を有するレジスト材料を用いてフォトリソグラフィー法と熱リフローによりレンズ母型を形成し、ドライエッチング法によりレンズ母型の形状をアクリル透明樹脂層に転写する転写タイプ（特許文献２参照）がある。
As a means for preventing such a decrease in sensitivity of the miniaturized solid-state imaging device, in order to efficiently capture light into the light receiving portion of the photoelectric conversion device, the light incident from the object is condensed and photoelectrically A technique has been proposed in which a microlens that leads to a light receiving portion of a conversion element is formed on the photoelectric conversion element. By condensing the light with the microlens and guiding it to the light receiving portion of the photoelectric conversion element, the apparent aperture ratio of the light receiving portion can be increased, and the sensitivity of the solid-state imaging device can be improved. The microlens formation method is a flow lens type (patented) that forms a lens shape using the thermal reflow property of the material after selectively patterning the acrylic photosensitive resin that is the material of the microlens by photolithography. A lens matrix is formed on a flat layer of acrylic transparent resin, which is a microlens material, using a resist material having alkali solubility, photosensitivity, and heat flow, by photolithography and thermal reflow. In addition, there is a transfer type (see Patent Document 2) that transfers the shape of the lens matrix to the acrylic transparent resin layer by a dry etching method.
図２は、着色透明樹脂パターンからなるカラーフィルタ画素上に１画素毎に１個の無色透明なマイクロレンズを設けて集光し、色分解した光を光電変換素子の受光部に導く従来のカラー固体撮像素子を一例として、固体撮像素子の構造を説明するための模式断面図である。
カラー固体撮像素子１は、半導体基板２上に規則的に設けた複数の光電変換素子３を平面配置した固体撮像素子画素部の受光面側表面４に、透明平坦化層５を介して、複数色を繰り返し配列する着色透明画素パターン６を複数の光電変換素子３に１対１に対応させて設け、さらに第二の透明平坦化層５１により着色透明画素パターン６を配列した平面上の平坦化を行った後に、上記のマイクロレンズ７を設けてなる。上記の説明は、固体撮像素子の受光有効領域を示す矢印Ａの領域に関する説明であるが、受光有効領域に隣接する周辺領域を示す矢印Ｂの領域においては、光電変換素子３が不要の領域で隣接する着色透明画素パターン６に代えて、同等の高さ空間を層として物理的に埋める充填層６１を設ける。また、第二の透明平坦化層５１上にマイクロレンズ７は不要であるが、固体撮像素子として最終的にパッケージ化する上で安定した実装に寄与するマイクロレンズとの並列層７１を設けることが多い。なお、これらの周辺領域Ｂの断面構造は、図示していないが周辺領域に設ける各種マーク類や電極端子や断裁線等の配置により、多様に変化する。
FIG. 2 shows a conventional color in which one colorless and transparent microlens is provided for each pixel on a color filter pixel composed of a colored transparent resin pattern, and the light is separated into a light receiving portion of a photoelectric conversion element. It is a schematic cross section for demonstrating the structure of a solid-state image sensor by taking a solid-state image sensor as an example.
A plurality of color solid-state imaging devices 1 are arranged on the light-receiving surface side surface 4 of a solid-state imaging device pixel portion in which a plurality of photoelectric conversion devices 3 regularly provided on a semiconductor substrate 2 are arranged in a plane via a transparent flattening layer 5. Flattening on a plane in which colored transparent pixel patterns 6 for repeatedly arranging colors are provided corresponding to the plurality of photoelectric conversion elements 3 on a one-to-one basis, and further, colored transparent pixel patterns 6 are arranged by a second transparent flattening layer 51. After performing the above, the microlens 7 is provided. The above description relates to the area indicated by the arrow A indicating the effective light receiving area of the solid-state imaging device. In the area indicated by the arrow B indicating the peripheral area adjacent to the effective light receiving area, the photoelectric conversion element 3 is an unnecessary area. Instead of the adjacent colored transparent pixel pattern 6, a filling layer 61 that physically fills an equivalent height space as a layer is provided. Although the microlens 7 is not required on the second transparent planarization layer 51, a parallel layer 71 with a microlens that contributes to stable mounting when finally packaged as a solid-state imaging device is provided. Many. Although not shown, the cross-sectional structure of the peripheral region B varies depending on various marks, electrode terminals, cutting lines, and the like provided in the peripheral region.
図３は、従来のカラー固体撮像素子１の構造の他の一例を説明するための模式断面図であって、図２と同様な構造のマイクロレンズ７の表面に反射防止膜８を設けた例である。マイクロレンズ７は、固体撮像素子の感度向上に資するために外光を効率良く集光する目的で設けるものであるから、マイクロレンズを透過する光量が減ることは問題である。従って、表面反射による光量の減衰を防止するために、マイクロレンズ７の表面に反射防止膜８を設ける（特許文献３参照）。 FIG. 3 is a schematic cross-sectional view for explaining another example of the structure of the conventional color solid-state imaging device 1, in which an antireflection film 8 is provided on the surface of the microlens 7 having the same structure as that of FIG. It is. Since the microlens 7 is provided for the purpose of efficiently collecting external light in order to contribute to improving the sensitivity of the solid-state imaging device, it is a problem that the amount of light transmitted through the microlens is reduced. Therefore, an antireflection film 8 is provided on the surface of the microlens 7 in order to prevent attenuation of light quantity due to surface reflection (see Patent Document 3).
図３に模式的に示した断面構造を有する固体撮像素子において、マイクロレンズ７の表面に設ける反射防止膜８は、一般にマイクロレンズ形成樹脂である有機材料上に、マイクロレンズ形成樹脂より屈折率の小さい二酸化珪素等の無機材料の薄層を形成することにより、表面反射率を低減することができる。しかし、積層された両層の熱膨張係数が異なることや、無機材料成膜時の膜に内在するストレス等が原因となって、マイクロレンズ表面に形成した反射防止膜にクラックが発生することがあり、均一に高透過率の性能を維持したいマイクロレンズの性能が損なわれ、固体撮像素子の不具合となる。 In the solid-state imaging device having the cross-sectional structure schematically shown in FIG. 3, the antireflection film 8 provided on the surface of the microlens 7 has a refractive index higher than that of the microlens forming resin on an organic material that is generally a microlens forming resin. By forming a thin layer of a small inorganic material such as silicon dioxide, the surface reflectance can be reduced. However, cracks may occur in the antireflection film formed on the surface of the microlens due to the difference in the thermal expansion coefficient between the two layers and the stress inherent in the film during the formation of the inorganic material. In other words, the performance of a microlens that wants to maintain the performance of high transmittance uniformly is impaired, which becomes a problem of the solid-state imaging device.
本発明は、前記の問題点に鑑みて提案するものであり、本発明が解決しようとする課題は、固体撮像素子に設けるマイクロレンズの高透過率化を目的としてマイクロレンズ表面に形成する反射防止膜に、クラックによる欠陥が発生しない、高感度の固体撮像素子の構
造を提供することである。
The present invention is proposed in view of the above-mentioned problems, and the problem to be solved by the present invention is to prevent reflection formed on the surface of the microlens for the purpose of increasing the transmittance of the microlens provided in the solid-state imaging device. It is to provide a highly sensitive solid-state imaging device structure in which defects due to cracks do not occur in a film.
上記の課題を解決するための手段として、請求項１に記載の発明は、半導体基板上に複数の光電変換素子を平面配置した固体撮像素子画素部の受光面側に、光電変換素子の各々に１対１に対応してマイクロレンズを受光有効領域に備えた固体撮像素子において、受光有効領域に隣接する周辺領域に、受光有効領域を取り囲むように複数の凸状体をマイクロレンズと同一の材料で設け、マイクロレンズと凸状体の表面を均一に覆う反射防止膜を形成したことを特徴とする固体撮像素子である。 As means for solving the above-mentioned problems, the invention according to claim 1 is directed to the light-receiving surface side of the solid-state imaging element pixel unit in which a plurality of photoelectric conversion elements are arranged in a plane on a semiconductor substrate. In a solid-state imaging device having a microlens in a light receiving effective region corresponding to one-to-one, a plurality of convex bodies are made of the same material as the microlens in a peripheral region adjacent to the light receiving effective region so as to surround the light receiving effective region The solid-state imaging device is characterized in that an antireflection film that uniformly covers the surface of the microlens and the convex body is formed.
また、請求項２に記載の発明は、前記凸状体が、受光有効領域に備えたマイクロレンズと同一形状であることを特徴とする請求項１に記載の固体撮像素子である。 The invention according to claim 2 is the solid-state imaging device according to claim 1, wherein the convex body has the same shape as the microlens provided in the light receiving effective region.
また、請求項３に記載の発明は、前記反射防止膜が、屈折率がマイクロレンズより小さい単層反射防止膜であることを特徴とする請求項１または２に記載の固体撮像素子である。 The invention according to claim 3 is the solid-state imaging device according to claim 1 or 2, wherein the antireflection film is a single-layer antireflection film having a refractive index smaller than that of the microlens.
また、請求項４に記載の発明は、前記反射防止膜が、高屈折率層と低屈折率層とを交互に積層した２層以上の多層反射防止膜であることを特徴とする請求項１または２に記載の固体撮像素子である。 The invention according to claim 4 is characterized in that the antireflection film is a multilayer antireflection film having two or more layers in which high refractive index layers and low refractive index layers are alternately laminated. Or it is a solid-state image sensor of 2.
また、請求項５に記載の発明は、前記反射防止膜が、二酸化珪素を含むことを特徴とする請求項１〜４のいずれかに記載の固体撮像素子である。 The invention according to claim 5 is the solid-state imaging device according to any one of claims 1 to 4, wherein the antireflection film contains silicon dioxide.
本発明は、受光有効領域に隣接する周辺領域に、受光有効領域を取り囲むように複数の凸状体をマイクロレンズと同一の材料で設け、マイクロレンズと凸状体の表面を均一に覆う反射防止膜を形成するので、クラックによる欠陥が発生しない反射防止膜をマイクロレンズ表面に形成でき、均一に高透過率の性能を維持するマイクロレンズを設けて、高感度の固体撮像素子を容易に提供することができる。 In the present invention, a plurality of convex bodies are provided with the same material as the microlens in the peripheral area adjacent to the effective light receiving area so as to surround the effective light receiving area, and the surface of the microlens and the convex body is uniformly covered with antireflection. Since the film is formed, an antireflection film that does not cause defects due to cracks can be formed on the surface of the microlens, and a microlens that uniformly maintains high transmittance performance is provided to easily provide a high-sensitivity solid-state imaging device be able to.
以下、図面に従って、本発明を実施するための形態について説明する。
図１は、本発明の固体撮像素子の構造の一例を説明するための模式断面図である。
Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view for explaining an example of the structure of the solid-state imaging device of the present invention.
本発明は、半導体基板２上に複数の光電変換素子３を平面配置した固体撮像素子１の画素部の受光面側に、光電変換素子３の各々に１対１に対応してマイクロレンズ７を受光有効領域Ａに備えた固体撮像素子において、受光有効領域Ａに隣接する周辺領域Ｂに、受光有効領域Ａを平面上で取り囲むように複数の凸状体７２をマイクロレンズと同一の材料で設け、マイクロレンズと凸状体の表面を均一に覆う反射防止膜８を形成したことを特徴とする固体撮像素子１である。以下、カラー固体撮像素子の例に従って、具体的に説明する。 In the present invention, the microlenses 7 are provided on the light receiving surface side of the pixel portion of the solid-state imaging device 1 in which a plurality of photoelectric conversion devices 3 are arranged on the semiconductor substrate 2 in a one-to-one correspondence with each of the photoelectric conversion devices 3. In the solid-state imaging device provided in the effective light receiving area A, a plurality of convex bodies 72 are provided in the peripheral area B adjacent to the effective light receiving area A so as to surround the effective light receiving area A on the plane with the same material as the microlens. The solid-state imaging device 1 is characterized in that an antireflection film 8 that uniformly covers the surface of the microlens and the convex body is formed. Hereinafter, it demonstrates concretely according to the example of a color solid-state image sensor.
カラー固体撮像素子１は、半導体基板２上に規則的に設けた複数の光電変換素子３を平面配置した固体撮像素子画素部の受光面側表面４に、透明平坦化層５を介して、複数色を繰り返し配列する着色透明画素パターン６を複数の光電変換素子３に１対１に対応させて設け、さらに第二の透明平坦化層５１により着色透明画素パターン６を配列した平面上の平坦化を行った後に、上記のマイクロレンズ７を設けてなる。 A plurality of color solid-state imaging devices 1 are arranged on the light-receiving surface side surface 4 of a solid-state imaging device pixel portion in which a plurality of photoelectric conversion devices 3 regularly provided on a semiconductor substrate 2 are arranged in a plane via a transparent flattening layer 5. Flattening on a plane in which colored transparent pixel patterns 6 for repeatedly arranging colors are provided corresponding to the plurality of photoelectric conversion elements 3 on a one-to-one basis, and further, colored transparent pixel patterns 6 are arranged by a second transparent flattening layer 51. After performing the above, the microlens 7 is provided.
透明平坦化層５としては、例えば、無色透明なアクリル樹脂溶液を０．１μｍ程度の厚さで均一に回転塗布し、熱処理して硬化する。着色透明画素パターン６は、所定の分光透過率特性を有する特定の色の顔料等の色素成分とアルカリ可溶性樹脂を含む感光性材料を、前記透明平坦化層上に回転塗布し、露光、現像工程を含む一連のフォトリソグラフィー法によりパターン形成し、熱硬化して種々の耐性を得る。上記の着色透明画素パターン形成工程を異なる色についても同様に繰り返すことにより、必要な複数色からなる着色透明画素パターンの繰り返し配列を得ることができる。
なお、受光有効領域Ａに隣接する周辺領域を示す矢印Ｂの領域においては、光電変換素子３が不要の領域であって、隣接する着色透明画素パターン６に代えて、同等の高さ空間を層として物理的に埋める充填層６１を設ける。充填層６１には、複数色の着色透明画素パターンを作る材料の内の１色を充てて、該色のパターンと同時形成することができる。
As the transparent flattening layer 5, for example, a colorless and transparent acrylic resin solution is uniformly spin-coated with a thickness of about 0.1 μm and cured by heat treatment. The colored transparent pixel pattern 6 is formed by spin-coating a photosensitive material containing a pigment component such as a specific color pigment having a predetermined spectral transmittance characteristic and an alkali-soluble resin on the transparent flattening layer, and exposing and developing processes. A pattern is formed by a series of photolithography methods including, and heat-cured to obtain various resistances. By repeating the above colored transparent pixel pattern forming step for different colors in the same manner, it is possible to obtain a repeated arrangement of necessary colored transparent pixel patterns composed of a plurality of colors.
It should be noted that the area indicated by the arrow B indicating the peripheral area adjacent to the effective light receiving area A is an area where the photoelectric conversion element 3 is not required, and an equivalent height space is formed instead of the adjacent colored transparent pixel pattern 6. A filling layer 61 that is physically filled is provided. The filling layer 61 is filled with one of the materials for forming a colored transparent pixel pattern of a plurality of colors and can be formed simultaneously with the pattern of the color.
着色透明画素パターンは、色によって、必要な分光透過率を得るための厚さに差が生じ易い。そこで、透明平坦化層５より平坦化効果を大きくするために充分に厚い層で、透明平坦化層５と同様の材料を、着色透明画素パターン上に塗布、熱処理して、第二の透明平坦化層５１を形成することが好ましい。
上記平坦化がなされた表面の内、受光有効領域Ａには、所定の形状に設計されたマイクロレンズ７を光電変換素子３の各々に対応した平面上の各位置に設ける。また、受光有効領域Ａに隣接する周辺領域Ｂに、受光有効領域Ａを平面上で取り囲むように複数の凸状体７２をマイクロレンズ７と同一の材料で設ける。
The colored transparent pixel pattern tends to have a difference in thickness for obtaining a required spectral transmittance depending on the color. Therefore, the second transparent flattened layer 5 is thicker than the transparent flattened layer 5 and is thick enough to apply the same material as the transparent flattened layer 5 on the colored transparent pixel pattern and heat-treat. It is preferable to form the chemical layer 51.
Among the flattened surfaces, in the light receiving effective region A, microlenses 7 designed in a predetermined shape are provided at respective positions on a plane corresponding to each of the photoelectric conversion elements 3. A plurality of convex bodies 72 are provided with the same material as that of the microlens 7 in the peripheral area B adjacent to the effective light receiving area A so as to surround the effective light receiving area A on a plane.
なお、周辺領域Ｂに設ける凸状体７２をどのように配置するかは、図示していないが、多様に変化する。例えば、周辺領域Ｂに設ける各種マーク類や電極端子や断裁線等のパターンの配置により、該パターンを避ける位置に凸状体を設ける。しかし、周辺領域Ｂの中でも、受光有効領域Ａに隣接する受光有効領域Ａの特に近傍の領域には、前記各種マーク類や電極端子や断裁線等のパターンの配置を行わないことは設計上妥当であるので、本発明の凸状体７２を受光有効領域Ａを取り囲むように設けることができる。 Note that how to arrange the convex bodies 72 provided in the peripheral region B is not illustrated, but varies in various ways. For example, a convex body is provided at a position avoiding the pattern by arranging various marks provided in the peripheral region B, patterns of electrode terminals, cutting lines, and the like. However, in the peripheral area B, it is appropriate in design not to arrange the patterns such as the various marks, electrode terminals, and cutting lines in the area near the effective light receiving area A adjacent to the effective light receiving area A. Therefore, the convex body 72 of the present invention can be provided so as to surround the light receiving effective area A.
本発明は、受光有効領域Ａに設けるマイクロレンズ７と、周辺領域Ｂに設ける凸状体７２とを、同一材料で設けることを特徴としている。同一材料で設けるマイクロレンズと凸状体の形成は、同時に形成することが合理的であり、形成方法としては、従来よりマイクロレンズの形成方法として実施された前述の２方式が可能である。すなわち、マイクロレンズの素材となるアクリル系感光性樹脂をフォトリソグラフィー法により選択的にパターン形成した後に、材料の熱リフロー性を利用してレンズ形状を作るフローレンズタイプや、マイクロレンズの素材となるアクリル透明樹脂の平坦層の上に、アルカリ可溶性と感光性と熱リフロー性を有するレジスト材料を用いてフォトリソグラフィー法と熱リフローによりレンズ母型を形成し、ドライエッチング法によりレンズ母型の形状をアクリル透明樹脂層に転写する転写タイプが、いずれも可能である。 The present invention is characterized in that the microlens 7 provided in the light receiving effective region A and the convex body 72 provided in the peripheral region B are provided with the same material. It is reasonable to form the microlens and the convex body provided by the same material at the same time, and as the forming method, the above-described two methods that have been conventionally implemented as a microlens forming method are possible. In other words, after selectively patterning an acrylic photosensitive resin, which is a microlens material, by photolithography, it becomes a flow lens type that uses the thermal reflow property of the material to create a lens shape, or a microlens material On the flat layer of acrylic transparent resin, a lens matrix is formed by photolithography and thermal reflow using a resist material having alkali solubility, photosensitivity and thermal reflow, and the shape of the lens matrix is formed by dry etching. Any transfer type that transfers to the acrylic transparent resin layer is possible.
前記凸状体の形状は、上述の各形成方法におけるフォトリソグラフィー法を利用する工程で、使用する露光用マスクのパターン設計を考慮することにより、各種の形状が可能であるが、受光有効領域に備えたマイクロレンズと同一形状とすることが、最も容易であり、かつ、後の工程でクラックによる欠陥が発生しない反射防止膜をマイクロレンズ上に設ける上でも最適である。 The shape of the convex body can be various shapes by considering the pattern design of the exposure mask to be used in the process of using the photolithography method in each of the above forming methods. It is easiest to form the same shape as the provided microlens, and it is optimal for providing an antireflection film on the microlens that does not cause defects due to cracks in the subsequent process.
また、本発明は、前述のように同一材料で設けたマイクロレンズ７と凸状体７２の表面を、反射防止膜８で均一に覆うように形成する。マイクロレンズ７の表面に反射防止膜８を設けることのみによっても、マイクロレンズの表面反射による透過光量の減少を防ぐことができ、高感度の固体撮像素子を提供することができる。しかし、特に受光有効領域Ａの端部付近のマイクロレンズ表面上の反射防止膜は、一般に使用される無機材料の成膜時の膜に内在するストレスの解放等が原因となって、クラックが発生しやすい。そこで、本発明では、受光有効領域Ａに隣接する周辺領域Ｂに、受光有効領域Ａを取り囲むように複数の凸状体をマイクロレンズと同一の材料で設け、マイクロレンズと凸状体の表面を均一に覆う反射防止膜８を形成することにより、受光有効領域Ａの端部付近のマイクロレンズ表面上の反射防止膜が、反射防止膜８としての端部には該当しなくなり、ストレスの解放による緩和を生じる領域ではなくなるので、この領域でのクラックの発生を抑制できる。 Further, in the present invention, the microlens 7 and the convex body 72 provided with the same material as described above are formed so as to uniformly cover the surfaces of the convex body 72 with the antireflection film 8. Even by providing the antireflection film 8 only on the surface of the microlens 7, it is possible to prevent a decrease in the amount of transmitted light due to the surface reflection of the microlens, and it is possible to provide a highly sensitive solid-state imaging device. However, the antireflection film on the surface of the microlens near the edge of the effective light receiving area A is cracked due to the release of stress inherent in the film during the formation of the generally used inorganic material. It's easy to do. Therefore, in the present invention, a plurality of convex bodies are provided with the same material as the microlens in the peripheral area B adjacent to the light receiving effective area A so as to surround the light receiving effective area A, and the surface of the microlens and the convex body is provided. By forming the antireflection film 8 that uniformly covers, the antireflection film on the surface of the microlens near the end of the effective light receiving area A does not correspond to the end as the antireflection film 8, and the stress is released. Since it is no longer a region that causes relaxation, the occurrence of cracks in this region can be suppressed.
また、受光有効領域Ａから隣接する周辺領域Ｂに、マイクロレンズ７と凸状体７２の表面を連続する反射防止膜８は、前記２種類の下地の境界において、下地の形状が同一である方が、クラックの発生起因を与え難いので、凸状体７２の形状をマイクロレンズ７の形状と同一にすることが最適である。
なお、本発明では、周辺領域Ｂに設けた凸状体７２の表面に形成した反射防止膜８でのクラック発生は防止できないが、受光有効領域Ａの外での重大ではない欠陥に限定される。
Further, the antireflection film 8 in which the surface of the microlens 7 and the convex body 72 continues from the light receiving effective area A to the adjacent peripheral area B has the same base shape at the boundary between the two types of bases. However, since it is difficult to cause the occurrence of cracks, it is optimal to make the shape of the convex body 72 the same as the shape of the microlens 7.
In the present invention, the occurrence of cracks in the antireflection film 8 formed on the surface of the convex body 72 provided in the peripheral region B cannot be prevented, but is limited to non-critical defects outside the light receiving effective region A. .
前記反射防止膜８は、無機材料の単層膜または多層膜で、真空蒸着法やスパッタリング法等の真空成膜技術を用いて形成できる。
マイクロレンズの表面における光の表面反射率は、使用材料や製法により異なるが、例えば、従来のフローレンズタイプでは、屈折率１．６０、転写タイプでは、屈折率１．５５の光学特性により決まる表面反射率が、可視域平均値で、それぞれ約５．３％、約４．７％に得られていた。本発明の反射防止膜を単層膜で形成する場合には、反射防止膜の屈折率を、上記のマイクロレンズの屈折率より小さくすることにより、反射防止効果が得られる。例えば、屈折率１．４６の二酸化珪素の単層薄膜をマイクロレンズの表面に形成すると、可視域平均の表面反射率で約３．５％とすることができ、反射防止膜８を形成しない場合より表面反射率を低減できるので、高感度の固体撮像素子を提供することに寄与することができる。
The antireflection film 8 is a single layer film or a multilayer film of an inorganic material, and can be formed by using a vacuum film forming technique such as a vacuum deposition method or a sputtering method.
The surface reflectance of light on the surface of the microlens varies depending on the material used and the manufacturing method. For example, the surface is determined by the optical characteristics of a refractive index of 1.60 for a conventional flow lens type and a refractive index of 1.55 for a transfer type. The reflectivities were about 5.3% and about 4.7%, respectively, as average values in the visible range. When the antireflection film of the present invention is formed of a single layer film, the antireflection effect can be obtained by making the refractive index of the antireflection film smaller than the refractive index of the microlens. For example, when a single layer thin film of silicon dioxide having a refractive index of 1.46 is formed on the surface of the microlens, the average surface reflectance of the visible region can be about 3.5%, and the antireflection film 8 is not formed. Since the surface reflectance can be further reduced, it is possible to contribute to providing a highly sensitive solid-state imaging device.
図４は、マイクロレンズ表面における光の分光反射率を、反射防止膜の有無により比較したグラフである。点線で示す従来のマイクロレンズ表面の分光反射率に較べて、二酸化珪素被膜をマイクロレンズ表面に０．１μｍの厚さに形成した場合の、実線で示すマイクロレンズ表面の分光反射率は、可視光全域の波長に亘って、顕著に低下していることを示している。 FIG. 4 is a graph comparing the spectral reflectance of light on the microlens surface with and without the antireflection film. Compared with the spectral reflectance of the conventional microlens surface indicated by the dotted line, the spectral reflectance of the microlens surface indicated by the solid line when the silicon dioxide film is formed to a thickness of 0.1 μm on the surface of the microlens is visible light. It shows that it is significantly lowered over the entire wavelength range.
前記反射防止膜８は、高屈折率層と低屈折率層とを交互に積層した２層以上の多層反射防止膜であってもよい。ここで、高屈折率層としては、例えば、チタン、セリウム、タンタル、錫、インジウム、ジルコニウム、アルミニウム等の金属の酸化物、あるいはこれらの金属酸化物の混合物であり、屈折率が１．６０以上のものである。また、低屈折率層としては、屈折率が１．６０未満のもので、例えば、二酸化珪素を始めとする珪素系酸化物や、弗化マグネシウムの他、マグネシウム、ジルコニウム、アルミニウム等の金属の酸化物、あるいはこれらの金属酸化物の混合物が可能である。 The antireflection film 8 may be a multilayer antireflection film having two or more layers in which high refractive index layers and low refractive index layers are alternately laminated. Here, the high refractive index layer is, for example, a metal oxide such as titanium, cerium, tantalum, tin, indium, zirconium, aluminum, or a mixture of these metal oxides, and has a refractive index of 1.60 or more. belongs to. The low refractive index layer has a refractive index of less than 1.60. For example, silicon oxide such as silicon dioxide, magnesium fluoride, and other metals such as magnesium, zirconium and aluminum are oxidized. Or a mixture of these metal oxides.
前記反射防止膜を構成する無機材料の単層膜または多層膜に用いる薄膜材料の中でも、特に、二酸化珪素は、低コスト、高品質の膜を従来の真空成膜技術により容易に得ることができ、薄膜の光学的特性や耐性についても、成膜方法との関連で最も良く知られている材料の一つであるので、本発明に用いる反射防止膜の構成材料に含むことが好ましい。 Among the thin film materials used for the single-layer film or multilayer film of the inorganic material constituting the antireflection film, silicon dioxide, in particular, can easily obtain a low-cost, high-quality film by a conventional vacuum film formation technique. Since the optical properties and resistance of the thin film are also one of the most well-known materials in relation to the film forming method, they are preferably included in the constituent material of the antireflection film used in the present invention.
１・・・カラー固体撮像素子
２・・・半導体基板
３・・・光電変換素子
４・・・固体撮像素子画素部の受光面側表面
５・・・透明平坦化層
５１・・・第二の透明平坦化層
６・・・着色透明画素パターン
６１・・・充填層
７・・・マイクロレンズ
７１・・・マイクロレンズとの並列層
７２・・・凸状体
８・・・反射防止膜
Ａ・・・固体撮像素子の受光有効領域
Ｂ・・・受光有効領域に隣接する周辺領域
DESCRIPTION OF SYMBOLS 1 ... Color solid-state image sensor 2 ... Semiconductor substrate 3 ... Photoelectric conversion element 4 ... Light-receiving surface side surface 5 of a solid-state image sensor pixel part ... Transparent planarization layer 51 ... Second Transparent flattened layer 6 ... colored transparent pixel pattern 61 ... filling layer 7 ... microlens 71 ... parallel layer 72 with microlens ... convex body 8 ... antireflection film A ..Effective light receiving area B of the solid-state image sensor ... peripheral area adjacent to the light receiving effective area
Claims (5)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2011142702A JP2013012518A (en) | 2011-06-28 | 2011-06-28 | Solid state imaging device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2011142702A JP2013012518A (en) | 2011-06-28 | 2011-06-28 | Solid state imaging device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2013012518A true JP2013012518A (en) | 2013-01-17 |
Family
ID=47686189
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2011142702A Pending JP2013012518A (en) | 2011-06-28 | 2011-06-28 | Solid state imaging device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2013012518A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2016526294A (en) * | 2013-05-21 | 2016-09-01 | クラレト，ホルヘ ヴィセンテ ブラスコ | Monolithic integration of plenoptic lenses on photosensor substrates |
| WO2018131509A1 (en) * | 2017-01-13 | 2018-07-19 | ソニーセミコンダクタソリューションズ株式会社 | Image capture element, manufacturing method, and electronic device |
| WO2018139278A1 (en) * | 2017-01-30 | 2018-08-02 | ソニーセミコンダクタソリューションズ株式会社 | Image-capture element, manufacturing method, and electronic device |
| WO2018159344A1 (en) * | 2017-03-03 | 2018-09-07 | ソニーセミコンダクタソリューションズ株式会社 | Solid-state imaging element, electronic device, and semiconductor device |
| WO2020196620A1 (en) * | 2019-03-27 | 2020-10-01 | 株式会社クラレ | Fine uneven pattern film and head-up display device |
| WO2022181536A1 (en) * | 2021-02-25 | 2022-09-01 | ソニーセミコンダクタソリューションズ株式会社 | Photodetector and electronic apparatus |
| WO2023125979A1 (en) * | 2021-12-31 | 2023-07-06 | Jade Bird Display (shanghai) Limited | A micro led projector |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000156486A (en) * | 1998-11-20 | 2000-06-06 | Matsushita Electric Ind Co Ltd | Manufacture of slid state image sensor |
| JP2002299594A (en) * | 2001-04-03 | 2002-10-11 | Toppan Printing Co Ltd | Solid state image sensing element having infrared reflecting film and its manufacturing method |
| JP2008034521A (en) * | 2006-07-27 | 2008-02-14 | Matsushita Electric Ind Co Ltd | Solid-state imaging apparatus, and manufacturing method thereof |
| JP2009099804A (en) * | 2007-10-17 | 2009-05-07 | Sharp Corp | Solid-state imaging element, camera module, and electronic information equipment |
| JP2010021289A (en) * | 2008-07-09 | 2010-01-28 | Canon Inc | Image capturing apparatus, imaging system, and method of manufacturing image capturing apparatus |
| JP2010186818A (en) * | 2009-02-10 | 2010-08-26 | Sony Corp | Solid-state imaging apparatus and method of manufacturing the same, and electronic equipment |
| JP2011146481A (en) * | 2010-01-13 | 2011-07-28 | Sharp Corp | Solid-state imaging device |
-
2011
- 2011-06-28 JP JP2011142702A patent/JP2013012518A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000156486A (en) * | 1998-11-20 | 2000-06-06 | Matsushita Electric Ind Co Ltd | Manufacture of slid state image sensor |
| JP2002299594A (en) * | 2001-04-03 | 2002-10-11 | Toppan Printing Co Ltd | Solid state image sensing element having infrared reflecting film and its manufacturing method |
| JP2008034521A (en) * | 2006-07-27 | 2008-02-14 | Matsushita Electric Ind Co Ltd | Solid-state imaging apparatus, and manufacturing method thereof |
| JP2009099804A (en) * | 2007-10-17 | 2009-05-07 | Sharp Corp | Solid-state imaging element, camera module, and electronic information equipment |
| JP2010021289A (en) * | 2008-07-09 | 2010-01-28 | Canon Inc | Image capturing apparatus, imaging system, and method of manufacturing image capturing apparatus |
| JP2010186818A (en) * | 2009-02-10 | 2010-08-26 | Sony Corp | Solid-state imaging apparatus and method of manufacturing the same, and electronic equipment |
| JP2011146481A (en) * | 2010-01-13 | 2011-07-28 | Sharp Corp | Solid-state imaging device |
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2016526294A (en) * | 2013-05-21 | 2016-09-01 | クラレト，ホルヘ ヴィセンテ ブラスコ | Monolithic integration of plenoptic lenses on photosensor substrates |
| WO2018131509A1 (en) * | 2017-01-13 | 2018-07-19 | ソニーセミコンダクタソリューションズ株式会社 | Image capture element, manufacturing method, and electronic device |
| JPWO2018131509A1 (en) * | 2017-01-13 | 2019-11-21 | ソニーセミコンダクタソリューションズ株式会社 | Imaging device, manufacturing method, and electronic apparatus |
| JP7237595B2 (en) | 2017-01-13 | 2023-03-13 | ソニーセミコンダクタソリューションズ株式会社 | IMAGE SENSOR, MANUFACTURING METHOD, AND ELECTRONIC DEVICE |
| US10868052B2 (en) | 2017-01-13 | 2020-12-15 | Sony Semiconductor Solutions Corporation | Imaging element, manufacturing method, and electronic apparatus |
| US11217615B2 (en) | 2017-01-30 | 2022-01-04 | Sony Semiconductor Solutions Corporation | Imaging element, fabrication method, and electronic equipment |
| WO2018139278A1 (en) * | 2017-01-30 | 2018-08-02 | ソニーセミコンダクタソリューションズ株式会社 | Image-capture element, manufacturing method, and electronic device |
| US11670656B2 (en) | 2017-01-30 | 2023-06-06 | Sony Semiconductor Solutions Corporation | Imaging element, fabrication method, and electronic equipment |
| CN110352490A (en) * | 2017-03-03 | 2019-10-18 | 索尼半导体解决方案公司 | Solid-state image pickup element, electronic equipment and semiconductor device |
| US11121112B2 (en) | 2017-03-03 | 2021-09-14 | Sony Semiconductor Solutions Corporation | Solid-state image pickup element with dam to control resin outflow |
| US11647890B2 (en) | 2017-03-03 | 2023-05-16 | Sony Semiconductor Solutions Corporation | Solid-state image pickup element, electronic equipment, and semiconductor apparatus |
| WO2018159344A1 (en) * | 2017-03-03 | 2018-09-07 | ソニーセミコンダクタソリューションズ株式会社 | Solid-state imaging element, electronic device, and semiconductor device |
| CN113678028A (en) * | 2019-03-27 | 2021-11-19 | 株式会社可乐丽 | Fine concave-convex pattern film and flat display device |
| WO2020196620A1 (en) * | 2019-03-27 | 2020-10-01 | 株式会社クラレ | Fine uneven pattern film and head-up display device |
| WO2022181536A1 (en) * | 2021-02-25 | 2022-09-01 | ソニーセミコンダクタソリューションズ株式会社 | Photodetector and electronic apparatus |
| WO2023125979A1 (en) * | 2021-12-31 | 2023-07-06 | Jade Bird Display (shanghai) Limited | A micro led projector |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5845856B2 (en) | Solid-state imaging device, manufacturing method thereof, and electronic device | |
| TWI416715B (en) | A solid-state imaging device, a manufacturing method of a solid-state imaging device, and an electronic device | |
| JP2013012518A (en) | Solid state imaging device | |
| US7579209B2 (en) | Image sensor and fabricating method thereof | |
| JP2012204354A (en) | Solid state imaging device, manufacturing method thereof and electronic apparatus | |
| TW200403842A (en) | Solid image-pickup device and method of manufacturing the same | |
| JP2011096732A (en) | Solid-state imaging device, method of manufacturing the same, and electronic apparatus | |
| JP2004047682A (en) | Solid-state image pickup device | |
| WO2017082429A1 (en) | Solid-state imaging element and method for manufacturing same | |
| JP2010272654A (en) | Solid-state image pickup device and manufacturing method thereof | |
| US9978789B2 (en) | Image-sensing device | |
| US9583522B2 (en) | Image sensor and electronic device including the same | |
| JP2000180621A (en) | On-chip color filter and solid image pick-up element using the same | |
| JP2011171328A (en) | Solid-state image pickup element and method of manufacturing the same | |
| US20050045805A1 (en) | Solid-state image sensor and a manufacturing method thereof | |
| JP4998310B2 (en) | Solid-state imaging device and imaging apparatus using the same | |
| JP2011243749A (en) | Solid state image pickup device and manufacturing method thereof | |
| US8138467B2 (en) | Color filter array including color filters only of first type and second type, method of fabricating the same, and image pickup device including the same | |
| JP5027081B2 (en) | Color imaging device and method for manufacturing color imaging device | |
| JP6520400B2 (en) | Microlens for solid-state imaging device and method of forming microlens for solid-state imaging device | |
| TW200530957A (en) | Solid-state image sensor for improving sensing quality and manufacturing method thereof | |
| JP2018110147A (en) | Solid state imaging device and manufacturing method thereof | |
| JP2011061134A (en) | Semiconductor image sensor | |
| JP5446374B2 (en) | Solid-state imaging device and manufacturing method thereof | |
| JP2011165923A (en) | Color solid-state imaging element, and method of manufacturing the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20140521 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20150217 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20150219 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20150415 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20151117 |