JPH07235658A - Solid-state image sensor and formation of sensor structure thereof - Google Patents
Solid-state image sensor and formation of sensor structure thereofInfo
- Publication number
- JPH07235658A JPH07235658A JP6049859A JP4985994A JPH07235658A JP H07235658 A JPH07235658 A JP H07235658A JP 6049859 A JP6049859 A JP 6049859A JP 4985994 A JP4985994 A JP 4985994A JP H07235658 A JPH07235658 A JP H07235658A
- Authority
- JP
- Japan
- Prior art keywords
- sensor
- light
- charge transfer
- solid
- forming
- 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.)
- Granted
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、固体撮像装置に関し、
特に固体撮像装置におけるセンサ部の構造及びその形成
方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state image pickup device,
In particular, the present invention relates to a structure of a sensor unit in a solid-state imaging device and a method of forming the same.
【０００２】[0002]
【従来の技術】固体撮像装置の一例として、例えばイン
ターライン転送方式のＣＣＤ(ChargeCoupled Device)
エリアセンサの概略構成を図６に示す。同図において、
水平及び垂直方向にて２次元配列されて入射光を光電変
換し、その信号電荷を蓄積する複数個のセンサ部１と、
これらセンサ部１の垂直列毎に配されかつ垂直ブランキ
ング期間の一部にて読出しゲート部２を介して読み出さ
れた信号電荷を垂直方向に転送する垂直電荷転送部３と
によって撮像部４が構成されている。2. Description of the Related Art As an example of a solid-state image pickup device, for example, an interline transfer type CCD (Charge Coupled Device) is used.
A schematic configuration of the area sensor is shown in FIG. In the figure,
A plurality of sensor units 1 arranged two-dimensionally in the horizontal and vertical directions to photoelectrically convert incident light and store the signal charges thereof;
The image pickup section 4 is formed by the vertical charge transfer section 3 which is arranged for each vertical column of the sensor section 1 and which vertically transfers the signal charge read through the read gate section 2 in a part of the vertical blanking period. Is configured.
【０００３】この撮像部４において、センサ部１は例え
ばフォトダイオードからなり、垂直電荷転送部３はＣＣ
Ｄによって構成されている。センサ部１から垂直電荷転
送部３に読み出された信号電荷は、水平ブランキング期
間の一部にて１走査線に相当する部分ずつ順に水平転送
部５へ転送される。この１走査線分の信号電荷は、水平
電荷転送部５によって順次水平方向に転送される。In this image pickup section 4, the sensor section 1 is composed of, for example, a photodiode, and the vertical charge transfer section 3 is a CC.
It is composed of D. The signal charges read from the sensor unit 1 to the vertical charge transfer unit 3 are sequentially transferred to the horizontal transfer unit 5 in units of one scanning line in a part of the horizontal blanking period. The signal charges for one scanning line are sequentially transferred in the horizontal direction by the horizontal charge transfer section 5.
【０００４】水平電荷転送部５の出力側には、転送され
てきた信号電荷を検出して信号電圧に変換する例えばＦ
ＤＡ(Floating Diffusion Amplifier)からなる電荷検出
部６が配されている。図７に、センサ部１及び垂直電荷
転送部３の断面（図６のＡ‐Ａ′矢視断面）構造の要部
を示す。On the output side of the horizontal charge transfer section 5, for example, F, which detects the transferred signal charge and converts it into a signal voltage,
A charge detection unit 6 including a DA (Floating Diffusion Amplifier) is arranged. FIG. 7 shows a main part of a cross-sectional structure (a cross section taken along the line AA ′ in FIG. 6) of the sensor unit 1 and the vertical charge transfer unit 3.
【０００５】[0005]
【発明が解決しようとする課題】上記ＣＣＤエリアセン
サにおける垂直電荷転送部３では、図７に示すように、
センサ部１を除く部分、即ち転送電極７１の外側にアル
ミニウム等からなる遮光膜７２を形成することで、信号
電荷転送領域７３への外部光の入射を遮断する構造を採
っている。In the vertical charge transfer section 3 of the CCD area sensor, as shown in FIG.
By forming a light-shielding film 72 made of aluminum or the like on the portion excluding the sensor portion 1, that is, on the outside of the transfer electrode 71, a structure for blocking the incidence of external light on the signal charge transfer region 73 is adopted.
【０００６】しかしながら、従来のセンサ構造では、図
７から明らかなように、センサ部１の表面が平坦面とし
て形成されているので、センサ部１に光が斜めに入射し
た場合、センサ表面で反射した光のうち遮光膜７２の下
端面７２ａに入射する成分があり、この反射光成分が基
板表面と遮光膜７２の下端面７２ａ又は転送電極７１と
の間で多重反射を繰り返し、最終的に信号電荷転送領域
７３に飛び込んで光電子を発生し、スミア成分を増加さ
せるという問題があった。However, in the conventional sensor structure, as is apparent from FIG. 7, since the surface of the sensor portion 1 is formed as a flat surface, when light is obliquely incident on the sensor portion 1, the light is reflected by the sensor surface. There is a component of the reflected light that is incident on the lower end surface 72a of the light shielding film 72, and this reflected light component repeats multiple reflection between the substrate surface and the lower end surface 72a of the light shielding film 72 or the transfer electrode 71, and finally the signal. There is a problem in that the smear component is increased by jumping into the charge transfer region 73 to generate photoelectrons.
【０００７】本発明は、上記課題に鑑みてなされたもの
であり、その目的とするところは、電荷転送部における
基板表面と遮光膜の下端面又は転送電極との間での多重
反射をなくし、スミアの低減を可能とした固体撮像装置
のセンサ構造及びその形成方法を提供することにある。The present invention has been made in view of the above problems, and an object thereof is to eliminate multiple reflection between the substrate surface in the charge transfer portion and the lower end surface of the light shielding film or the transfer electrode, It is an object of the present invention to provide a sensor structure of a solid-state imaging device capable of reducing smear and a method for forming the sensor structure.
【０００８】[0008]
【課題を解決するための手段】請求項１記載の固体撮像
装置は、入射光を光電変換してその信号電荷を蓄積する
少なくとも１列分配列された複数個のセンサ部と、この
複数個のセンサ部から読み出された信号電荷を転送する
電荷転送部とを具備し、複数個のセンサ部の各々の入射
面の少なくとも周縁部が凸凹形状をなした構成となって
いる。According to a first aspect of the present invention, there is provided a solid-state image pickup device, wherein a plurality of sensor portions arranged for at least one row for photoelectrically converting incident light and storing signal charges thereof, and a plurality of the sensor portions. A charge transfer unit that transfers the signal charges read from the sensor unit is provided, and at least the peripheral portion of the incident surface of each of the plurality of sensor units has an uneven shape.
【０００９】請求項２記載の固体撮像装置は、請求項１
記載の固体撮像装置において、複数個のセンサ部の各々
の入射面全面が凸凹形状をなした構成となっている。請
求項３記載の固体撮像装置は、請求項１又は２記載の固
体撮像装置において、凸凹形状の凸部のピッチ及び高さ
が、入射光の波長の１／１０〜１０倍に設定された構成
となっている。According to a second aspect of the present invention, there is provided the solid-state image pickup device according to the first aspect.
In the solid-state imaging device described above, the entire incident surface of each of the plurality of sensor units is configured to be uneven. The solid-state imaging device according to claim 3 is the solid-state imaging device according to claim 1 or 2, wherein the pitch and height of the convexes and concaves are set to 1/10 to 10 times the wavelength of incident light. Has become.
【００１０】請求項４記載のセンサ構造の形成方法は、
センサ表面上にシリコン酸化膜を形成するとともに、そ
の上に半球状グレインポリシリコンを形成し、この半球
状グレインポリシリコンの隙間からその下のシリコン酸
化膜をエッチングする。請求項５記載のセンサ構造の形
成方法は、請求項４記載のセンサ構造の形成方法におい
て、シリコン酸化膜をエッチングした後、そのエッチン
グ部分のセンサ表面にトレンチを形成する。A method of forming a sensor structure according to claim 4,
A silicon oxide film is formed on the surface of the sensor, hemispherical grain polysilicon is formed on the silicon oxide film, and the silicon oxide film below is etched through the gap between the hemispherical grain polysilicon. According to a fifth aspect of the present invention, in the method of forming the sensor structure according to the fourth aspect, after the silicon oxide film is etched, a trench is formed on the sensor surface of the etched portion.
【００１１】[0011]
【作用】請求項１記載の固体撮像装置において、センサ
部に光が斜めに入射したとき、その入射光は入射面周縁
部の凸凹形状を形成する凸部の側面で反射することで、
電荷転送部側へは入り込まない。したがって、電荷転送
部における基板表面と遮光膜の下端面又は転送電極との
間での多重反射は起こらず、よって電荷転送部の転送領
域に入射しない。また、凸部の側面で反射した光がさら
に他の凸部の側面で反射を繰り返すことで、最終的に基
板側へ透過し、光電変換される。その結果、センサ部の
感度が向上する。In the solid-state image pickup device according to claim 1, when light is obliquely incident on the sensor portion, the incident light is reflected by the side surface of the convex portion forming the irregular shape of the peripheral portion of the incident surface,
It does not enter the charge transfer unit side. Therefore, multiple reflection does not occur between the substrate surface of the charge transfer portion and the lower end surface of the light-shielding film or the transfer electrode, and therefore the charge does not enter the transfer region of the charge transfer portion. Further, the light reflected on the side surface of the convex portion is repeatedly reflected on the side surface of another convex portion, and finally is transmitted to the substrate side and photoelectrically converted. As a result, the sensitivity of the sensor unit is improved.
【００１２】請求項２記載の固体撮像装置において、セ
ンサ部にその上方より入射した光は入射面の凸凹面を透
過する際に、その一部が反射する。この反射した光は、
凸部の側面で反射を繰り返すことで、最終的に基板側へ
透過する。すなわち、入射面でのある程度の光の反射は
避けられないが、その反射光も最終的にセンサ部へ取り
込まれる。その結果、センサ部の感度が向上する。請求
項３記載の固体撮像装置では、凸凹形状の凸部のピッチ
及び高さを入射光の波長の１／１０〜１０倍に設定する
ことで、上記作用が有効に発揮される。In the solid-state image pickup device according to the second aspect, a part of the light incident on the sensor portion from above is reflected when passing through the uneven surface of the incident surface. This reflected light is
By repeating the reflection on the side surface of the convex portion, the light is finally transmitted to the substrate side. That is, although some reflection of light on the incident surface is inevitable, the reflected light is finally taken into the sensor unit. As a result, the sensitivity of the sensor unit is improved. In the solid-state imaging device according to the third aspect of the present invention, the above effect can be effectively exhibited by setting the pitch and height of the convex and concave portions to 1/10 to 10 times the wavelength of the incident light.
【００１３】請求項４記載のセンサ構造の形成方法にお
いて、センサ表面上にシリコン酸化膜を形成し、その上
に半球状グレインポリシリコンを形成する。半球状グレ
インポリシリコンは微小粒径のものとして形成される。
この半球状グレインポリシリコンの隙間からシリコン酸
化膜をエッチングする。このエッチングにより、センサ
表面が局所的に露出し、微小な凸部が形成される。請求
項５記載のセンサ構造の形成方法において、エッチング
によって露出したセンサ表面にトレンチを形成し、これ
によって凸部の高さを設定する。In a method of forming a sensor structure according to a fourth aspect, a silicon oxide film is formed on the sensor surface, and hemispherical grain polysilicon is formed on the silicon oxide film. Hemispherical grain polysilicon is formed with a fine grain size.
The silicon oxide film is etched through the gap of the hemispherical grain polysilicon. By this etching, the sensor surface is locally exposed and a minute convex portion is formed. In the method of forming a sensor structure according to claim 5, a trench is formed in the sensor surface exposed by etching, and the height of the convex portion is set by this.
【００１４】[0014]
【実施例】以下、本発明の実施例を図面に基づいて詳細
に説明する。図１は、本発明に係るＣＣＤエリアセンサ
におけるセンサ部及び垂直電荷転送部の断面構造図であ
り、図６のＡ‐Ａ′矢視断面を示す。図１において、Ｎ
型シリコン基板１１上にはＰ層からなるオーバーフロー
バリア１２を介してＰウェル１３が積層されている。Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a sectional structural view of a sensor unit and a vertical charge transfer unit in a CCD area sensor according to the present invention, and shows a sectional view taken along the line AA ′ of FIG. In FIG. 1, N
A P well 13 is stacked on the type silicon substrate 11 with an overflow barrier 12 made of a P layer interposed therebetween.
【００１５】センサ部１は、Ｐウェル１３の表面側に形
成されたＰ+ 層からなる正孔蓄積層１４と、その下のＮ
層からなる信号電荷蓄積層１５とからなるＨＡＤ(Holl
Accumulation Diode) 構造を採ることで、感度の向上と
暗電流の低減を図っている。この正孔蓄積層１４及び信
号電荷蓄積層１５に隣接してチャネルストップ部１６が
形成されている。垂直電荷転送部３は、基板１１の表面
側に形成された信号電荷転送領域１７と、基板表面上に
シリコン酸化膜(SiO2)よりなる絶縁層１８を介して形成
されたポリシリコンよりなる転送電極１９とによって構
成されている。The sensor section 1 includes a hole accumulation layer 14 formed of a P + layer formed on the surface side of the P well 13 and an N layer below the hole accumulation layer 14.
HAD (Holl) including a signal charge storage layer 15 including a layer
Accumulation Diode) structure is adopted to improve sensitivity and reduce dark current. A channel stop portion 16 is formed adjacent to the hole storage layer 14 and the signal charge storage layer 15. The vertical charge transfer section 3 includes a signal charge transfer region 17 formed on the front surface side of the substrate 11 and a transfer formed of polysilicon formed on the surface of the substrate via an insulating layer 18 made of a silicon oxide film (SiO 2 ). It is composed of the electrode 19.
【００１６】また、センサ部１と垂直電荷転送部３の間
には、センサ部１で光電変換され、信号電荷蓄積層１５
に蓄積された信号電荷を垂直電荷転送部３へ読み出すた
めの読出しゲート部２が設けられている。この読出しゲ
ート部２のゲート電極として、本例では転送電極１９が
兼用されている。そして、センサ部１を除いて読出しゲ
ート部２、垂直電荷転送部３及びチャネルストップ部１
６上には、絶縁層１８を介してアルミニウム等からなる
遮光膜２０が転送電極１９の外側を覆うように設けられ
ている。Between the sensor unit 1 and the vertical charge transfer unit 3, photoelectric conversion is performed by the sensor unit 1 and the signal charge storage layer 15 is formed.
A read gate unit 2 is provided for reading out the signal charges accumulated in the vertical charge transfer unit 3. In this example, the transfer electrode 19 is also used as the gate electrode of the read gate portion 2. Then, except for the sensor unit 1, the readout gate unit 2, the vertical charge transfer unit 3, and the channel stop unit 1
A light-shielding film 20 made of aluminum or the like is provided on the outer surface of the transfer electrode 19 via an insulating layer 18.
【００１７】上記のセンサ構造において、センサ部１の
入射面の少なくとも周縁部、好ましくは入射面全面が凸
凹形状をなしている。この凸凹形状の一例の拡大断面を
図２に示す。同図において、凸凹形状を形成する個々の
凸部２１は円錐形状をなし、そのピッチｐ及び高さｈが
入射光の波長の１／１０〜１０倍程度になるように設定
されている。一例として、入射光の波長を４００ｎｍ〜
７００ｎｍとしたとき、凸部２１のピッチｐ及び高さｈ
は、０．０４μｍ〜７μｍ程度で、しかも画素サイズの
１／１０程度以内に設定される。In the above sensor structure, at least the peripheral portion of the incident surface of the sensor portion 1, preferably the entire incident surface, has an uneven shape. An enlarged cross section of an example of this uneven shape is shown in FIG. In the figure, each convex portion 21 forming the concave and convex shape has a conical shape, and its pitch p and height h are set to be about 1/10 to 10 times the wavelength of incident light. As an example, the wavelength of incident light is 400 nm to
When it is 700 nm, the pitch p and the height h of the convex portion 21 are
Is about 0.04 μm to 7 μm, and is set within about 1/10 of the pixel size.
【００１８】上述したように、センサ部１の入射面の少
なくとも周縁部が凸凹形状をなしていることにより、図
３に示すように、センサ部１に光が斜めに入射しても、
円錐状の凸部２１の斜面（側面）で反射する。すると、
その反射光はセンサ部１の上方側ではなく、その下方側
に向けて反射することになる。したがって、センサ部１
の表面での反射光が、垂直電荷転送部３における基板表
面と遮光膜２０の下端面又は転送電極１９との間で多重
反射を繰り返すことはなく、よってその反射光が垂直電
荷転送部３側へ入射することはないので、スミアを大幅
に低減できる。As described above, since at least the peripheral portion of the incident surface of the sensor portion 1 is formed in a concave-convex shape, even if light is incident on the sensor portion 1 obliquely, as shown in FIG.
The light is reflected by the slope (side surface) of the conical convex portion 21. Then,
The reflected light is reflected not toward the upper side of the sensor unit 1 but toward the lower side thereof. Therefore, the sensor unit 1
The reflected light on the surface of the vertical charge transfer unit 3 does not repeat multiple reflection between the substrate surface in the vertical charge transfer unit 3 and the lower end surface of the light shielding film 20 or the transfer electrode 19, and thus the reflected light is on the vertical charge transfer unit 3 side. Smear can be significantly reduced because it does not enter.
【００１９】しかも、円錐状の凸部２１の斜面での反射
光は、他の凸部の斜面との間で反射を何回か繰り返すこ
とによって最終的に基板側へ透過し、反射光成分も光電
変換されることになるため、センサ部１の感度を向上で
きる。ところで、センサ部１の表面が平坦な場合、入射
した光の一部は基板側へ透過し、光電変換後信号電荷と
なって蓄積され、有効な信号となる。しかし、シリコン
は屈折率が一般にセンサ部１上に形成される透明膜（カ
ラーフィルタを含む）よりも大きいため、センサ部１の
表面で数１０％は反射されてしまい、光を損失している
のが現状である。Moreover, the reflected light on the slope of the conical convex portion 21 is finally transmitted to the substrate side by repeating the reflection with the slopes of the other convex portions several times, and the reflected light component is also present. Since photoelectric conversion is performed, the sensitivity of the sensor unit 1 can be improved. By the way, when the surface of the sensor unit 1 is flat, a part of the incident light is transmitted to the substrate side and is accumulated as signal charges after photoelectric conversion and becomes an effective signal. However, since the refractive index of silicon is generally larger than that of the transparent film (including the color filter) formed on the sensor unit 1, several tens of percent of the light is reflected on the surface of the sensor unit 1 and light is lost. is the current situation.
【００２０】ところが、本実施例においては、センサ部
１の入射面の周縁部のみならず、入射面全面を凸凹形状
としたことにより、センサ部１に上方より入射した光
は、図３に示すように、円錐状の凸部２１の斜面を透過
するとともにその一部が反射することになるが、その反
射光が当該斜面での反射を何回か繰り返すことで最終的
に基板側へ透過する。これにより、従来損失となってい
た反射光成分についても光電変換が行われることになる
ため、センサ部１の感度を向上できる。However, in this embodiment, not only the peripheral portion of the incident surface of the sensor portion 1 but also the entire incident surface is made uneven, so that the light incident on the sensor portion 1 from above is shown in FIG. As described above, the light is transmitted through the slope of the conical convex portion 21 and a part thereof is reflected, but the reflected light is finally transmitted to the substrate side by repeating reflection on the slope several times. . As a result, photoelectric conversion is also performed on the reflected light component that has been a loss in the related art, so that the sensitivity of the sensor unit 1 can be improved.
【００２１】なお、凸部２１の円錐状の頂角を十分に鋭
角に形成することで、入射光の上方への反射を極めて低
く抑えることが可能となり、センサ部１の感度をより向
上できることになる。また、センサ部１の上方への反射
を低減できることで、セルゴーストなどのフレアの問題
も解消できる。ここに、セルゴーストとは、センサ部１
で反射した光が、ＣＣＤエリアセンサ上にマウントされ
たレンズ等の光学系で多重干渉を起こすことにより、微
小な画素セルが拡大されて映し出される現象を言う。By forming the conical apex angle of the convex portion 21 to a sufficiently acute angle, the upward reflection of incident light can be suppressed to a very low level, and the sensitivity of the sensor unit 1 can be further improved. Become. Moreover, since the reflection of the sensor portion 1 upward can be reduced, the problem of flare such as cell ghost can be solved. Here, the cell ghost is the sensor unit 1
This is a phenomenon in which minute pixel cells are enlarged and projected by causing multiple interference of light reflected by the optical system such as a lens mounted on the CCD area sensor.
【００２２】これらの作用・効果は、円錐状の凸部２１
のピッチｐ及び高さｈを、先述した如く入射光の波長の
１／１０〜１０倍程度に、しかも画素サイズの１／１０
程度以内に設定することで有効に発揮される。ちなみ
に、円錐状の凸部２１のピッチｐ及び高さｈが小さすぎ
ると、入射光に対して反射の効果はなくなり、逆に大き
すぎると、素子のサイズに比べてセンサ形状が与える他
への悪影響が大きなものとなる。These actions and effects are achieved by the conical convex portion 21.
The pitch p and the height h are set to about 1/10 to 10 times the wavelength of the incident light and 1/10 of the pixel size as described above.
It is effective when set within the range. By the way, if the pitch p and the height h of the conical convex portions 21 are too small, the effect of reflecting the incident light is lost, and conversely if they are too large, the sensor shape gives more than the size of the element. The adverse effect will be significant.
【００２３】なお、本実施例では、センサ表面の凸凹形
状を形成する凸部２１を円錐状のものとしたが、この形
状に限定されるものではなく、例えば図４に示す如き略
半球状の凸部２１′であっても良く、要は、センサ表面
が平坦面でなく、凸凹であれば、所期の目的を達成する
ことができる。In the present embodiment, the convex portion 21 forming the irregular shape of the sensor surface is a conical shape, but the shape is not limited to this shape, and for example, a substantially hemispherical shape as shown in FIG. It may be a convex portion 21 ′. In short, if the sensor surface is not a flat surface but is concave and convex, the intended purpose can be achieved.
【００２４】次に、上述したセンサ構造の形成方法につ
いて、図５（ａ）〜（ｄ）の工程図に基づいて説明す
る。先ず、（ａ）工程１では、センサ部１上に転送電極
１８上よりも薄い、例えば５ｎｍ〜３０ｎｍ程度のシリ
コン酸化膜(SiO2)を成長させる。次に、ＨＳＧ(Hemisph
erical Grained：半球状グレイン）ポリシリコン(Poly-
Si) を全面に０．１μｍ程度の微小粒径で成長させる。Next, a method of forming the above-mentioned sensor structure will be described with reference to the process diagrams of FIGS. First, in step (a) 1, a silicon oxide film (SiO 2 ) having a thickness of, for example, about 5 nm to 30 nm, which is thinner than that on the transfer electrode 18, is grown on the sensor unit 1. Next, HSG (Hemisph
erical Grained: Poly-Silicon
Si) is grown on the entire surface with a fine grain size of about 0.1 μm.
【００２５】このＨＳＧポリシリコンの形成に際して
は、 Si2H6ガスを用いて核付けを行うことによって低温
で核発生させる。そして、これを中心に低温でポリシリ
コンの形成を行う。ＨＳＧの粒密度及び粒径は、 Si2H6
ガス流量及び基板温度によって決まる。また、核付け中
の Si2H6分圧は、例えば１０-5〜１０-4Ｔｏｒｒとす
る。ＨＳＧポリシリコンの形成方法としては、例えば学
会誌「応用物理」第６１巻第１１号（１９９２）１１４
７頁〜１１５１頁に開示のものが知られている。When forming the HSG polysilicon, nucleation is performed at a low temperature by performing nucleation using Si 2 H 6 gas. Then, with this as the center, polysilicon is formed at a low temperature. The grain density and grain size of HSG are Si 2 H 6
Determined by gas flow rate and substrate temperature. The Si 2 H 6 partial pressure during nucleation is, for example, 10 −5 to 10 −4 Torr. As a method of forming HSG polysilicon, for example, the journal "Applied Physics" Vol. 61, No. 11 (1992) 114 is published.
The ones disclosed on pages 7 to 1151 are known.
【００２６】（ｂ）工程２では、ＨＳＧポリシリコンの
隙間から、下のシリコン酸化膜をフッ化水素（ＨＦ）系
溶液でエッチングすることで、センサ表面を局所的に露
出させる。（ｃ）工程３では、シリコンのＲＩＥエッチ
ングにより、センサ表面に微小トレンチを形成する。こ
のとき、不要なポリシリコンは同時に除去される。
（ｄ）工程４では、界面準位安定化のため表面を熱処理
し、ＮＳＧ／ＰＳＧ堆積し、以降通常のＣＣＤプロセス
によって遮光膜１９を形成する。(B) In step 2, the sensor surface is locally exposed by etching the lower silicon oxide film with a hydrogen fluoride (HF) based solution from the gap of the HSG polysilicon. (C) In step 3, fine trenches are formed on the sensor surface by RIE etching of silicon. At this time, unnecessary polysilicon is simultaneously removed.
(D) In step 4, the surface is heat-treated to stabilize the interface state, NSG / PSG is deposited, and then the light-shielding film 19 is formed by a normal CCD process.
【００２７】上述したように、センサ表面の凸凹形状を
形成するに際し、センサ部１上に薄いシリコン酸化膜(S
iO2)を成長させ、その上にＨＳＧポリシリコンを形成
し、ＨＳＧポリシリコンの隙間から下のシリコン酸化膜
をエッチングしてセンサ表面を局所的に露出させること
で、画素サイズが小さいセンサ表面にも容易に凸凹形状
を形成することができる。As described above, when forming the uneven shape on the sensor surface, a thin silicon oxide film (S
iO 2 ) is grown, HSG polysilicon is formed on it, and the silicon oxide film below is etched from the gap of the HSG polysilicon to locally expose the sensor surface. It is also possible to easily form the uneven shape.
【００２８】なお、工程３では、局所的に露出したセン
サ表面に微小トレンチを形成するとしたが、これは必須
の要件ではない。ただし、トレンチを形成し、その深さ
を調整することで凸部の高さを任意に設定できる利点が
ある。また、センサ表面の凸凹形状の形成方法として
は、上記の形成方法に限られるものではなく、他にも種
々考えられる。例えば、画素サイズが大きいときは、リ
ソグラフィーとエッチングを使用して凸凹形状を形成す
ることも可能である。In step 3, the minute trenches are formed on the locally exposed sensor surface, but this is not an essential requirement. However, there is an advantage that the height of the convex portion can be arbitrarily set by forming the trench and adjusting the depth thereof. Further, the method of forming the uneven shape of the sensor surface is not limited to the above-mentioned forming method, and various other methods can be considered. For example, when the pixel size is large, it is possible to form the uneven shape by using lithography and etching.
【００２９】また、本発明は、ＣＣＤエリアセンサへの
適用に限定されるものではなく、センサ部が一列粉だけ
配列されたＣＣＤライン（リニア）センサ等、電荷転送
部を有する固体撮像装置全般に適用し得るものである。Further, the present invention is not limited to application to a CCD area sensor, and is applicable to all solid-state image pickup devices having a charge transfer unit such as a CCD line (linear) sensor in which the sensor unit is arranged in a single line of powder. It is applicable.
【００３０】[0030]
【発明の効果】以上説明したように、請求項１記載の発
明によれば、センサ部の各々の入射面の少なくとも周縁
部を凸凹形状としたことにより、センサ部に斜めに入射
した光が凸凹形状を形成する凸部の側面で反射し、電荷
転送部へは入り込まないため、スミアを大幅に低減でき
ることになる。また、凸部の側面で反射した光がさらに
他の凸部の側面で反射を繰り返すことで、最終的に基板
側へ透過し、光電変換されるため、センサ部の感度を向
上できることにもなる。As described above, according to the first aspect of the present invention, at least the peripheral portion of each incident surface of the sensor portion is formed into an uneven shape so that the light obliquely incident on the sensor portion is uneven. Since the light is reflected on the side surface of the convex portion forming the shape and does not enter the charge transfer portion, smear can be significantly reduced. Further, the light reflected on the side surface of the convex portion is further reflected on the side surface of another convex portion, and finally transmitted to the substrate side and photoelectrically converted, so that the sensitivity of the sensor portion can be improved. .
【００３１】請求項２記載の発明によれば、センサ部の
各々の入射面の周縁部のみならず、全面を凸凹形状にし
たことにより、センサ部にその上方より入射した光が入
射面の凸凹面を透過する際にその一部が反射しても、こ
の反射した光が凸部の側面で反射を繰り返すことで、最
終的に基板側へ透過し、光電変換されるため、センサ部
の感度を向上できることになる。なお、請求項３記載の
発明によれば、凸凹形状の凸部のピッチ及び高さを入射
光の波長の１／１０〜１０倍に設定することにより、上
記の作用・効果を最大限に発揮できることになる。According to the second aspect of the present invention, not only the peripheral portion of each incident surface of the sensor portion but also the entire surface is made uneven, so that light incident on the sensor portion from above is uneven on the incident surface. Even if a part of the light is reflected when passing through the surface, the reflected light is repeatedly reflected on the side surface of the convex portion, and finally it is transmitted to the substrate side and photoelectrically converted. Can be improved. According to the invention as set forth in claim 3, the pitch and height of the convex and concave portions are set to 1/10 to 10 times the wavelength of the incident light, thereby maximizing the above-mentioned action and effect. You can do it.
【００３２】請求項４記載の発明によれば、センサ表面
上にシリコン酸化膜を形成するとともに、その上に半球
状グレインポリシリコンを形成し、この半球状グレイン
ポリシリコンの隙間からシリコン酸化膜をエッチングす
るようにしたことにより、センサ表面が局所的に露出
し、微小な凸部が形成されるので、画素サイズの小さな
センサ部でも容易にそのセンサ表面を凸凹形状に形成す
ることができる。According to the fourth aspect of the present invention, a silicon oxide film is formed on the surface of the sensor, hemispherical grain polysilicon is formed on the silicon oxide film, and the silicon oxide film is formed from the gap between the hemispherical grain polysilicon. By performing etching, the sensor surface is locally exposed and a minute convex portion is formed. Therefore, even a sensor portion having a small pixel size can easily form the sensor surface in an uneven shape.
【００３３】請求項５記載の発明によれば、シリコン酸
化膜をエッチングした後、エッチングによって露出した
センサ表面にトレンチを形成するようにしたことによ
り、そのトレンチの深さを調整することによって凸部の
高さを任意に設定することができるので、入射光の波長
に対して凸部の高さを最適に設定できることになる。According to the fifth aspect of the present invention, after the silicon oxide film is etched, the trench is formed on the sensor surface exposed by the etching, so that the depth of the trench is adjusted to adjust the convex portion. Since the height of the convex portion can be arbitrarily set, the height of the convex portion can be optimally set with respect to the wavelength of the incident light.
【図１】本発明の一実施例を示す断面構造図である。FIG. 1 is a sectional structural view showing an embodiment of the present invention.
【図２】センサ表面の拡大断面図である。FIG. 2 is an enlarged sectional view of a sensor surface.
【図３】入射光の振舞いを示す図である。FIG. 3 is a diagram showing the behavior of incident light.
【図４】凸部の形状の変形例を示す断面図である。FIG. 4 is a cross-sectional view showing a modified example of the shape of the convex portion.
【図５】本発明によるセンサ構造の形成方法の工程図で
ある。FIG. 5 is a process drawing of a method for forming a sensor structure according to the present invention.
【図６】ＣＣＤエリアセンサの概略構成図である。FIG. 6 is a schematic configuration diagram of a CCD area sensor.
【図７】従来例を示す要部の断面図である。FIG. 7 is a cross-sectional view of a main part showing a conventional example.
１ センサ部 ３ 垂直電荷転送部 ５ 水平電荷転送部 １１ Ｎ型シリコン基板 １２ オーバーフローバリア １４ 正孔蓄積層 １５ 信号電荷蓄積層 １７ 信号電荷転送領域 １９ 転送電極 ２０ 遮光膜 ２１ 凸部 DESCRIPTION OF SYMBOLS 1 sensor part 3 vertical charge transfer part 5 horizontal charge transfer part 11 N-type silicon substrate 12 overflow barrier 14 hole storage layer 15 signal charge storage layer 17 signal charge transfer region 19 transfer electrode 20 light-shielding film 21 convex part
Claims (5)
積する少なくとも１列分配列された複数個のセンサ部
と、 前記複数個のセンサ部から読み出された信号電荷を転送
する電荷転送部とを具備し、 前記複数個のセンサ部の各々の入射面の少なくとも周縁
部が凸凹形状をなしていることを特徴とする固体撮像装
置。1. A plurality of sensor units arranged for at least one column for photoelectrically converting incident light and accumulating signal charges thereof, and charge transfer for transferring signal charges read from the plurality of sensor units. A solid-state imaging device, wherein at least a peripheral portion of an incident surface of each of the plurality of sensor portions has an uneven shape.
面が凸凹形状をなしていることを特徴とする請求項１記
載の固体撮像装置。2. The solid-state imaging device according to claim 1, wherein the entire incident surface of each of the plurality of sensor units has an uneven shape.
は、入射光の波長の１／１０〜１０倍に設定されている
ことを特徴とする請求項１又は２記載の固体撮像装置。3. The solid-state imaging device according to claim 1, wherein a pitch and a height of the convex-concave portions are set to 1/10 to 10 times a wavelength of incident light.
積する少なくとも１列分配列された複数個のセンサ部
と、前記複数個の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を具備した固体撮像装置における
センサ構造の形成方法であって、 センサ表面上にシリコン酸化膜を形成するとともに、そ
の上に半球状グレインポリシリコンを形成し、 前記半球状グレインポリシリコンの隙間から前記シリコ
ン酸化膜をエッチングすることを特徴とするセンサ構造
の形成方法。4. A plurality of sensor units arranged for at least one column for photoelectrically converting incident light and accumulating the signal charges thereof, and a charge transfer for transferring the signal charges read from the plurality of sensor units. A method for forming a sensor structure in a solid-state imaging device, comprising: forming a silicon oxide film on a sensor surface and forming hemispherical grain polysilicon on the silicon oxide film; A method for forming a sensor structure, comprising: etching the silicon oxide film from the substrate.
後、そのエッチング部分のセンサ表面にトレンチを形成
することを特徴とする請求項４記載のセンサ構造の形成
方法。5. The method for forming a sensor structure according to claim 4, wherein after the silicon oxide film is etched, a trench is formed on the sensor surface of the etched portion.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04985994A JP3271222B2 (en) | 1994-02-22 | 1994-02-22 | Solid-state imaging device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04985994A JP3271222B2 (en) | 1994-02-22 | 1994-02-22 | Solid-state imaging device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07235658A true JPH07235658A (en) | 1995-09-05 |
| JP3271222B2 JP3271222B2 (en) | 2002-04-02 |
Family
ID=12842787
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP04985994A Expired - Fee Related JP3271222B2 (en) | 1994-02-22 | 1994-02-22 | Solid-state imaging device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3271222B2 (en) |
Cited By (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007184560A (en) * | 2006-01-05 | 2007-07-19 | Korea Advanced Inst Of Sci Technol | Cmos image sensor and manufacturing method thereof |
| WO2010098223A1 (en) * | 2009-02-24 | 2010-09-02 | 浜松ホトニクス株式会社 | Photodiode manufacturing method and photodiode |
| WO2010098225A1 (en) * | 2009-02-24 | 2010-09-02 | 浜松ホトニクス株式会社 | Photodiode and photodiode array |
| WO2010098201A1 (en) * | 2009-02-24 | 2010-09-02 | 浜松ホトニクス株式会社 | Semiconductor photodetection element |
| WO2010098222A1 (en) * | 2009-02-25 | 2010-09-02 | 浜松ホトニクス株式会社 | Photodiode manufacturing method and photodiodes |
| WO2010098221A1 (en) * | 2009-02-24 | 2010-09-02 | 浜松ホトニクス株式会社 | Photodiode and photodiode array |
| WO2010098224A1 (en) * | 2009-02-24 | 2010-09-02 | 浜松ホトニクス株式会社 | Semiconductor light-detecting element |
| JP2016197733A (en) * | 2009-09-17 | 2016-11-24 | サイオニクス、エルエルシー | Photosensitive imaging element and related method |
| US9905599B2 (en) | 2012-03-22 | 2018-02-27 | Sionyx, Llc | Pixel isolation elements, devices and associated methods |
| US9911781B2 (en) | 2009-09-17 | 2018-03-06 | Sionyx, Llc | Photosensitive imaging devices and associated methods |
| US9939251B2 (en) | 2013-03-15 | 2018-04-10 | Sionyx, Llc | Three dimensional imaging utilizing stacked imager devices and associated methods |
| US10229951B2 (en) | 2010-04-21 | 2019-03-12 | Sionyx, Llc | Photosensitive imaging devices and associated methods |
| US10244188B2 (en) | 2011-07-13 | 2019-03-26 | Sionyx, Llc | Biometric imaging devices and associated methods |
| US10269861B2 (en) | 2011-06-09 | 2019-04-23 | Sionyx, Llc | Process module for increasing the response of backside illuminated photosensitive imagers and associated methods |
| US10347682B2 (en) | 2013-06-29 | 2019-07-09 | Sionyx, Llc | Shallow trench textured regions and associated methods |
| US10361083B2 (en) | 2004-09-24 | 2019-07-23 | President And Fellows Of Harvard College | Femtosecond laser-induced formation of submicrometer spikes on a semiconductor substrate |
| US10361232B2 (en) | 2009-09-17 | 2019-07-23 | Sionyx, Llc | Photosensitive imaging devices and associated methods |
| US10374109B2 (en) | 2001-05-25 | 2019-08-06 | President And Fellows Of Harvard College | Silicon-based visible and near-infrared optoelectric devices |
| US10505054B2 (en) | 2010-06-18 | 2019-12-10 | Sionyx, Llc | High speed photosensitive devices and associated methods |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7781485B2 (en) | 2004-11-09 | 2010-08-24 | Kyowa Hakko Kirin Co., Ltd. | Hsp90 family protein inhibitors |
-
1994
- 1994-02-22 JP JP04985994A patent/JP3271222B2/en not_active Expired - Fee Related
Cited By (41)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10374109B2 (en) | 2001-05-25 | 2019-08-06 | President And Fellows Of Harvard College | Silicon-based visible and near-infrared optoelectric devices |
| US10741399B2 (en) | 2004-09-24 | 2020-08-11 | President And Fellows Of Harvard College | Femtosecond laser-induced formation of submicrometer spikes on a semiconductor substrate |
| US10361083B2 (en) | 2004-09-24 | 2019-07-23 | President And Fellows Of Harvard College | Femtosecond laser-induced formation of submicrometer spikes on a semiconductor substrate |
| JP2007184560A (en) * | 2006-01-05 | 2007-07-19 | Korea Advanced Inst Of Sci Technol | Cmos image sensor and manufacturing method thereof |
| US7741664B2 (en) | 2006-01-05 | 2010-06-22 | Korea Advanced Institute Of Science & Technology | Complementary metal oxide semiconductor image sensor and method for fabricating the same |
| TWI476906B (en) * | 2009-02-24 | 2015-03-11 | Hamamatsu Photonics Kk | Photodiode and photodiode array |
| TWI495134B (en) * | 2009-02-24 | 2015-08-01 | Hamamatsu Photonics Kk | Method for manufacturing photodiode and photodiode |
| WO2010098224A1 (en) * | 2009-02-24 | 2010-09-02 | 浜松ホトニクス株式会社 | Semiconductor light-detecting element |
| WO2010098223A1 (en) * | 2009-02-24 | 2010-09-02 | 浜松ホトニクス株式会社 | Photodiode manufacturing method and photodiode |
| JP2010226074A (en) * | 2009-02-24 | 2010-10-07 | Hamamatsu Photonics Kk | Photodiode and photodiode array |
| JP2010226072A (en) * | 2009-02-24 | 2010-10-07 | Hamamatsu Photonics Kk | Semiconductor photodetector |
| JP2010226073A (en) * | 2009-02-24 | 2010-10-07 | Hamamatsu Photonics Kk | Photodiode, and photodiode array |
| JP2010226071A (en) * | 2009-02-24 | 2010-10-07 | Hamamatsu Photonics Kk | Semiconductor light-detecting element |
| JP2011014856A (en) * | 2009-02-24 | 2011-01-20 | Hamamatsu Photonics Kk | Method of manufacturing photodiode, and photodiode |
| KR20110128789A (en) * | 2009-02-24 | 2011-11-30 | 하마마츠 포토닉스 가부시키가이샤 | Semiconductor photodetection element |
| CN102334197A (en) * | 2009-02-24 | 2012-01-25 | 浜松光子学株式会社 | Semiconductor light-detecting element |
| WO2010098225A1 (en) * | 2009-02-24 | 2010-09-02 | 浜松ホトニクス株式会社 | Photodiode and photodiode array |
| US8629485B2 (en) | 2009-02-24 | 2014-01-14 | Hamamatsu Photonics K.K. | Semiconductor photodetection element |
| US8742528B2 (en) | 2009-02-24 | 2014-06-03 | Hamamatsu Photonics K.K. | Photodiode and photodiode array |
| US8916945B2 (en) | 2009-02-24 | 2014-12-23 | Hamamatsu Photonics K.K. | Semiconductor light-detecting element |
| WO2010098201A1 (en) * | 2009-02-24 | 2010-09-02 | 浜松ホトニクス株式会社 | Semiconductor photodetection element |
| US8994135B2 (en) | 2009-02-24 | 2015-03-31 | Hamamatsu Photonics K.K. | Photodiode and photodiode array |
| WO2010098221A1 (en) * | 2009-02-24 | 2010-09-02 | 浜松ホトニクス株式会社 | Photodiode and photodiode array |
| US9190551B2 (en) | 2009-02-24 | 2015-11-17 | Hamamatsu Photonics K.K. | Photodiode and photodiode array |
| US9419159B2 (en) | 2009-02-24 | 2016-08-16 | Hamamatsu Photonics K.K. | Semiconductor light-detecting element |
| US9972729B2 (en) | 2009-02-24 | 2018-05-15 | Hamamatsu Photonics K.K. | Photodiode and photodiode array |
| US9614109B2 (en) | 2009-02-24 | 2017-04-04 | Hamamatsu Photonics K.K. | Photodiode and photodiode array |
| WO2010098222A1 (en) * | 2009-02-25 | 2010-09-02 | 浜松ホトニクス株式会社 | Photodiode manufacturing method and photodiodes |
| JP2010199289A (en) * | 2009-02-25 | 2010-09-09 | Hamamatsu Photonics Kk | Method of manufacturing photodiode, and photodiode |
| US8564087B2 (en) | 2009-02-25 | 2013-10-22 | Hamamatsu Photonics K.K. | Photodiode manufacturing method and photodiodes |
| US10361232B2 (en) | 2009-09-17 | 2019-07-23 | Sionyx, Llc | Photosensitive imaging devices and associated methods |
| JP2016197733A (en) * | 2009-09-17 | 2016-11-24 | サイオニクス、エルエルシー | Photosensitive imaging element and related method |
| US9911781B2 (en) | 2009-09-17 | 2018-03-06 | Sionyx, Llc | Photosensitive imaging devices and associated methods |
| US10229951B2 (en) | 2010-04-21 | 2019-03-12 | Sionyx, Llc | Photosensitive imaging devices and associated methods |
| US10505054B2 (en) | 2010-06-18 | 2019-12-10 | Sionyx, Llc | High speed photosensitive devices and associated methods |
| US10269861B2 (en) | 2011-06-09 | 2019-04-23 | Sionyx, Llc | Process module for increasing the response of backside illuminated photosensitive imagers and associated methods |
| US10244188B2 (en) | 2011-07-13 | 2019-03-26 | Sionyx, Llc | Biometric imaging devices and associated methods |
| US9905599B2 (en) | 2012-03-22 | 2018-02-27 | Sionyx, Llc | Pixel isolation elements, devices and associated methods |
| US9939251B2 (en) | 2013-03-15 | 2018-04-10 | Sionyx, Llc | Three dimensional imaging utilizing stacked imager devices and associated methods |
| US10347682B2 (en) | 2013-06-29 | 2019-07-09 | Sionyx, Llc | Shallow trench textured regions and associated methods |
| US11069737B2 (en) | 2013-06-29 | 2021-07-20 | Sionyx, Llc | Shallow trench textured regions and associated methods |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3271222B2 (en) | 2002-04-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3271222B2 (en) | Solid-state imaging device | |
| US7511750B2 (en) | Photo-electric converting device and its driving method, and its manufacturing method, solid-state image pickup device and its driving method and its manufacturing method | |
| JP4235787B2 (en) | Manufacturing method of solid-state imaging device | |
| US8148672B2 (en) | Optical member with high and low refractive index layers | |
| JP2621767B2 (en) | Solid-state imaging device | |
| US6849476B2 (en) | Method of manufacturing a solid-state imaging device | |
| JPH10270672A (en) | Solid-state image pickup element | |
| JP2006147991A (en) | Solid state image sensor, and optical appliance having the same | |
| JPH04223371A (en) | Solid-state image sensing device | |
| US20220406832A1 (en) | Image sensor and imaging device | |
| JPH0750401A (en) | Solid state image pick-up device and manufacturing method thereof | |
| JPH0774332A (en) | Ccd solid-state imaging device | |
| KR100545972B1 (en) | Solid state pickup device and driving method thereof | |
| JPH0945884A (en) | Solid-state image pickup device and manufacture thereof | |
| JPS61154283A (en) | Solid image pick-up element | |
| JP4645578B2 (en) | Solid-state imaging device and method for manufacturing solid-state imaging device | |
| JP2825966B2 (en) | Solid-state imaging device with micro lens | |
| JP2877382B2 (en) | Solid-state imaging device | |
| JP2008103764A (en) | Solid-state imaging element, and method of manufacturing same | |
| JPH0878654A (en) | Solid-state pick-up device | |
| JPS59196667A (en) | Solid-state image pickup device | |
| JPH0590551A (en) | Solid-state image pick-up device | |
| JPS6251254A (en) | Solid-state image pickup device | |
| JPH10294446A (en) | Solid-state image pickup element | |
| JPH0832045A (en) | Solid state image pickup element and its manufacture |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080125 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090125 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100125 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100125 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110125 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110125 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120125 Year of fee payment: 10 |
|
| LAPS | Cancellation because of no payment of annual fees |