JP2780512B2 - Solid-state imaging device - Google Patents
Solid-state imaging deviceInfo
- Publication number
- JP2780512B2 JP2780512B2 JP3108934A JP10893491A JP2780512B2 JP 2780512 B2 JP2780512 B2 JP 2780512B2 JP 3108934 A JP3108934 A JP 3108934A JP 10893491 A JP10893491 A JP 10893491A JP 2780512 B2 JP2780512 B2 JP 2780512B2
- Authority
- JP
- Japan
- Prior art keywords
- interlayer insulating
- photoelectric conversion
- film
- insulating film
- imaging device
- 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.)
- Expired - Lifetime
Links
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- Solid State Image Pick-Up Elements (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、固体撮像素子に関し、
特にＣＣＤ固体撮像素子に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state imaging device,
In particular, it relates to a CCD solid-state imaging device.
【０００２】[0002]
【従来の技術】固体撮像素子は、撮像管に比べて小型、
軽量で焼き付けがない等の理由によりＶＴＲ一体型ビデ
オカメラ等の用途に幅広く使用されている。この固体撮
像素子にとって大きな問題点の一つが、電荷転送部に光
電変換領域以外で発生した信号電荷が漏れ込み、画面
上、光が当たっている部分の上下に白い帯状の偽信号を
発生するスミアリングである。このスミア特性を改善す
るために、従来は図３に示すような素子構成をとってき
た。2. Description of the Related Art A solid-state imaging device is smaller than an imaging tube,
It is widely used for applications such as VTR integrated video cameras because of its light weight and no burning. One of the major problems with this solid-state imaging device is the smear that signal charges generated in areas other than the photoelectric conversion region leak into the charge transfer section and generate white band-like false signals above and below the light-exposed area on the screen. It is a ring. In order to improve the smear characteristics, an element configuration as shown in FIG. 3 has conventionally been adopted.
【０００３】図３の（ａ）は、固体撮像素子の感光部の
断面図、図３の（ｂ）は同配線部の断面図である。同図
において、１はｎ型半導体基板、２はｐ型ウェル層、３
は光電変換領域、４は電荷転送領域、５は素子分離領
域、６ａはゲート酸化膜、６ｂはフィールド酸化膜、７
はゲート電極、８ａは層間絶縁膜、９ａは遮光用金属
膜、９ｂは配線用金属膜、１０は保護膜である。FIG. 3A is a cross-sectional view of a photosensitive portion of a solid-state imaging device, and FIG. 3B is a cross-sectional view of the wiring portion. In the figure, 1 is an n-type semiconductor substrate, 2 is a p-type well layer, 3
Is a photoelectric conversion region, 4 is a charge transfer region, 5 is an element isolation region, 6a is a gate oxide film, 6b is a field oxide film, 7
Is a gate electrode, 8a is an interlayer insulating film, 9a is a light shielding metal film, 9b is a wiring metal film, and 10 is a protective film.
【０００４】図３に示す素子においては、層間絶縁膜８
ａの膜厚を薄くすることにより、即ち、半導体基板と遮
光用金属膜９ａとの距離を短くすることにより、光がそ
の回折効果により光電変換領域３以外に漏れ込むのを防
止している。[0004] In the device shown in FIG.
By reducing the thickness of a, that is, by shortening the distance between the semiconductor substrate and the light-shielding metal film 9a, it is possible to prevent light from leaking out of the photoelectric conversion region 3 due to its diffraction effect.
【０００５】図４は、遮光用金属膜−基板間距離とスミ
アとの関係を示す特性図である。同図に示されるよう
に、遮光用金属膜下の層間絶縁膜の膜厚を薄くすること
によりスミア特性を改善することができる。FIG. 4 is a characteristic diagram showing the relationship between the distance between the light-shielding metal film and the substrate and the smear. As shown in the figure, the smear characteristic can be improved by reducing the thickness of the interlayer insulating film below the light shielding metal film.
【０００６】[0006]
【発明が解決しようとする課題】しかしながら、上述し
た従来の素子構造においては、遮光用金属膜下の層間絶
縁膜の膜厚を薄くした場合、同時に形成される配線用金
属膜下の層間絶縁膜も薄くなるため、配線用金属膜下の
領域の導電型が反転し配線容量が著しく増加したり、寄
生ＭＯＳトランジスタが動作してしまうという欠点があ
った。However, in the above-described conventional element structure, when the thickness of the interlayer insulating film below the light-shielding metal film is reduced, the interlayer insulating film below the wiring metal film formed simultaneously is formed. Therefore, the conductivity type of the region under the metal film for wiring is inverted, so that the wiring capacitance is significantly increased, and the parasitic MOS transistor operates.
【０００７】[0007]
【課題を解決するための手段】本発明の固体撮像装置
は、光電変換領域と、光電変換領域により光電変換され
た信号電荷がゲート電極により転送される電荷転送領域
とを含む感光部を有し、光電変換領域上に設けられる層
間絶縁膜の厚さを、光電変換領域の光透過領域を除いて
感光部に形成される遮光膜とゲート電極との間に設けら
れる層間絶縁膜の厚さよりも薄くしたものである。 SUMMARY OF THE INVENTION A solid-state imaging device according to the present invention.
Is photoelectrically converted by the photoelectric conversion region and the photoelectric conversion region.
Charge transfer area where the transferred signal charge is transferred by the gate electrode
Having a photosensitive portion containing: and a layer provided on the photoelectric conversion region
The thickness of the inter-insulation film excluding the light transmission area of the photoelectric conversion area
Provided between the light shielding film formed on the photosensitive section and the gate electrode
The thickness is smaller than the thickness of the interlayer insulating film to be formed.
【０００８】[0008]
【実施例】次に、本発明の参考例について図面を参照し
て説明する。図１は本発明の第１の参考例を示す図であ
って、図１の（ａ）は感光部の、また図１の（ｂ）は配
線部の断面図である。Next, a reference example of the present invention will be described with reference to the drawings. FIG. 1 is a view showing a first reference example of the present invention. FIG. 1 (a) is a sectional view of a photosensitive section, and FIG. 1 (b) is a sectional view of a wiring section.
【０００９】同図において、１はｎ型半導体基板、２は
ｐ型ウェル層、３は光電変換領域、４は電荷転送領域、
５は素子分離領域、６ａはゲート酸化膜、６ｂはフィー
ルド酸化膜、７はゲート電極、８ａは層間絶縁膜、８ｂ
は本実施例において、感光部以外の領域に新たに設けら
れた第２の層間絶縁膜、９ａは遮光用金属膜、９ｂは配
線用金属膜、１０は保護膜である。In FIG. 1, 1 is an n-type semiconductor substrate, 2 is a p-type well layer, 3 is a photoelectric conversion region, 4 is a charge transfer region,
5 is an element isolation region, 6a is a gate oxide film, 6b is a field oxide film, 7 is a gate electrode, 8a is an interlayer insulating film, 8b
In the present embodiment, is a second interlayer insulating film newly provided in a region other than the photosensitive portion, 9a is a light shielding metal film, 9b is a wiring metal film, and 10 is a protective film.
【００１０】次に、図１の参考例の製造プロセスについ
て説明する。層間絶縁膜８ａを形成するまでの工程は従
来と同様な方法を用いる。層間絶縁膜８ａを形成した
後、通常のフォトリソグラフィ法を用いて感光部（光電
変換領域３および電荷転送領域４）をフォトレジストに
て被覆した後、 Ｈ2 ＳｉＦ6 ＋２Ｈ2 Ｏ←→ＳｉＯ2 ＋６ＨＦ Ｈ3 ＢＯ3 ＋４ＨＦ←→ＢＦ4 -＋Ｈ3 Ｏ+ ＋２Ｈ2 Ｏ にて示される液相成長法により、前記感光部以外の部分
に比較的厚い第２の層間絶縁膜８ｂを所望の厚さ（例え
ば５００ｎｍ程度）に選択成長させる。前記フォトレジ
ストを除去した後、従来と同様な方法により金属膜９
ａ、９ｂおよび保護膜１０を形成することにより、本発
明の第１の参考例の固体撮像素子が得られる。Next, the manufacturing process of the reference example of FIG. 1 will be described. The steps up to the formation of the interlayer insulating film 8a use the same method as the conventional method. After forming the interlayer insulating film 8a, the photosensitive portion (the photoelectric conversion region 3 and the charge transfer region 4) is covered with a photoresist by using a normal photolithography method, and then H 2 SiF 6 + 2H 2 O ← → SiO 2 + 6HF H 3 BO 3 + 4HF ← → BF 4 - + H 3 O + + 2H 2 by the liquid phase growth method represented by O, the exposed portion other than the portion in a relatively thick second interlayer insulating film 8b desired thickness (For example, about 500 nm). After removing the photoresist, the metal film 9 is formed in the same manner as in the prior art.
a, by forming 9b and protective layer 10, the solid-state imaging device of the first exemplary embodiment of the present invention is obtained.
【００１１】図２は、本発明の第２の参考例を示す図で
あって、図２の（ａ）は感光部の、また図２の（ｂ）は
配線部の断面図である。本参考例の先の参考例と相違す
る点は、配線部において第２の層間絶縁膜８ｂの下に窒
化シリコン膜１１が形成されている点であって、これ以
外の点では先の参考例と異なるところはない。[0011] Figure 2 is a diagram showing a second exemplary embodiment of the present invention, in FIG. 2 (a) of the photosensitive portion, also in FIG. 2 (b) is a cross-sectional view of a wiring portion. Differs from the previous exemplary embodiment of the present reference example, be a point that silicon nitride film 11 under the second interlayer insulation film 8b is formed in the wiring portion, the previous reference example in terms other than the above There is no difference.
【００１２】次に、図２の参考例の製造プロセスについ
て説明する。従来と同様な方法で層間絶縁膜８ａまで形
成した後、窒化シリコン膜１１を素子全体に成長させ、
さらに所望の厚さ（例えば５００ｎｍ程度）に第２の層
間絶縁膜８ｂを成長させる。Next, the manufacturing process of the reference example of FIG. 2 will be described. After forming up to the interlayer insulating film 8a by the same method as the conventional method, a silicon nitride film 11 is grown on the entire device,
Further, the second interlayer insulating film 8b is grown to a desired thickness (for example, about 500 nm).
【００１３】然る後、写真食刻法（ウェット法）を用い
て、感光部（光電変換領域３および電荷転送領域４）の
第２の層間絶縁膜８ｂを窒化シリコン膜１１をストップ
膜として選択的に除去する。次に、第２の層間絶縁膜８
ｂをマスクとして窒化シリコン膜１１をウェットエッチ
ング法にて選択的に除去し、さらに、従来と同様な方法
により金属膜９ａ、９ｂおよび保護膜１０を形成するこ
とにより、本発明の第２の参考例の固体撮像素子が得ら
れる。Thereafter, the second interlayer insulating film 8b of the photosensitive portion (the photoelectric conversion region 3 and the charge transfer region 4) is selected using the silicon nitride film 11 as a stop film by using a photolithography method (wet method). Removed. Next, the second interlayer insulating film 8
The b and silicon nitride film 11 is selectively removed by wet etching as a mask, further, by forming the metal film 9a, 9b and the protective layer 10 by conventional and similar methods, a second reference of the present invention An example solid state imaging device is obtained.
【００１４】以上の参考例では、感光部全体に第２の層
間絶縁膜を形成しないようにしていたが、これを変更し
て光電変換領域上のみにこれを設けないようにしたのが
本発明である。 [0014] In above Example, that had not to form a second interlayer insulating film on the entire photosensitive portion, and is not provided it only to the photoelectric conversion region to change this
This is the invention.
【００１５】[0015]
【発明の効果】以上説明したように、本発明の固体撮像
素子では、光電変換領域と、光電変換領域により光電変
換された信号電荷がゲート電極により転送される電荷転
送領域とを含む感光部を有し、光電変換領域上に設けら
れる層間絶縁膜の厚さを、光電変換領域の光透過領域を
除いて感光部に形成される遮光膜とゲート電極との間に
設けられる層間絶縁膜の厚さよりも薄くすることによ
り、参考例よりもゲート電極と遮光膜間の浮遊容量を低
減することができ、より高速な動作をさせることが可能
になる。 As described above, in the solid-state imaging device of the present invention, the photoelectric conversion region and the photoelectric conversion region
The converted signal charge is transferred by the gate electrode.
A photosensitive area including a transfer area, and provided on the photoelectric conversion area.
The thickness of the interlayer insulating film to be
Except between the light shielding film formed on the photosensitive part and the gate electrode
By making it thinner than the thickness of the interlayer insulating film provided
The stray capacitance between the gate electrode and the light-shielding film is lower than in the reference example.
Can be reduced, allowing faster operation
become.
【図１】 本発明の第１の実施例を示す断面図。FIG. 1 is a sectional view showing a first embodiment of the present invention.
【図２】 本発明の第２の実施例を示す断面図。FIG. 2 is a sectional view showing a second embodiment of the present invention.
【図３】 従来例の断面図。FIG. 3 is a sectional view of a conventional example.
【図４】 遮光用金属膜下の層間絶縁膜の膜厚とスミア
との関係を示す特性図。FIG. 4 is a characteristic diagram showing a relationship between the thickness of an interlayer insulating film below a light-shielding metal film and smear.
１…ｎ型半導体基板、 ２…ｐ型ウェル層、 ３…
光電変換領域、 ４…電荷転送領域、 ５…素子分
離領域、 ６ａ…ゲート酸化膜、 ６ｂ…フィール
ド酸化膜、 ７…ゲート電極、 ８ａ…層間絶縁
膜、 ８ｂ…第２の層間絶縁膜、 ９ａ…遮光用金
属膜、 ９ｂ…配線用金属膜、 １０…保護膜、
１１…窒化シリコン膜。1 ... n-type semiconductor substrate, 2 ... p-type well layer, 3 ...
Photoelectric conversion region, 4: charge transfer region, 5: element isolation region, 6a: gate oxide film, 6b: field oxide film, 7: gate electrode, 8a: interlayer insulating film, 8b: second interlayer insulating film, 9a ... 9b: metal film for wiring, 10: protective film,
11 ... silicon nitride film.
Claims (1)
光電変換された信号電荷がゲート電極により転送される
電荷転送領域とを含む感光部を有する固体撮像装置にお
いて、前記光電変換領域上に設けられる層間絶縁膜の厚
さを、前記光電変換領域の光透過領域を除いて前記感光
部に形成される遮光膜と前記ゲート電極との間に設けら
れる層間絶縁膜の厚さよりも薄くしたことを特徴とする
固体撮像素子。 1. A photoelectric conversion region, comprising:
Photoelectrically converted signal charges are transferred by the gate electrode
Solid-state imaging device having a photosensitive portion including a charge transfer region.
The thickness of an interlayer insulating film provided on the photoelectric conversion region.
Except for the light transmitting region of the photoelectric conversion region,
Between the light-shielding film formed in the portion and the gate electrode.
Characterized by being thinner than the thickness of the interlayer insulating film
Solid-state imaging device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3108934A JP2780512B2 (en) | 1991-04-12 | 1991-04-12 | Solid-state imaging device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3108934A JP2780512B2 (en) | 1991-04-12 | 1991-04-12 | Solid-state imaging device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0590546A JPH0590546A (en) | 1993-04-09 |
| JP2780512B2 true JP2780512B2 (en) | 1998-07-30 |
Family
ID=14497358
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3108934A Expired - Lifetime JP2780512B2 (en) | 1991-04-12 | 1991-04-12 | Solid-state imaging device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2780512B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5427541B2 (en) * | 2009-10-08 | 2014-02-26 | 富士フイルム株式会社 | Solid-state imaging device, manufacturing method thereof, and imaging apparatus |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2570264B2 (en) * | 1986-07-18 | 1997-01-08 | ソニー株式会社 | Solid-state imaging device |
-
1991
- 1991-04-12 JP JP3108934A patent/JP2780512B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0590546A (en) | 1993-04-09 |
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