JPH01138752A - Laminated solid-state image sensing device - Google Patents
Laminated solid-state image sensing deviceInfo
- Publication number
- JPH01138752A JPH01138752A JP62297965A JP29796587A JPH01138752A JP H01138752 A JPH01138752 A JP H01138752A JP 62297965 A JP62297965 A JP 62297965A JP 29796587 A JP29796587 A JP 29796587A JP H01138752 A JPH01138752 A JP H01138752A
- Authority
- JP
- Japan
- Prior art keywords
- film
- electrode
- silicide
- pixel electrode
- solid
- 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
- 229910021332 silicide Inorganic materials 0.000 claims abstract description 52
- FVBUAEGBCNSCDD-UHFFFAOYSA-N silicide(4-) Chemical compound [Si-4] FVBUAEGBCNSCDD-UHFFFAOYSA-N 0.000 claims abstract description 48
- 239000002184 metal Substances 0.000 claims abstract description 20
- 229910052751 metal Inorganic materials 0.000 claims abstract description 20
- 239000007864 aqueous solution Substances 0.000 claims abstract description 10
- 239000000758 substrate Substances 0.000 claims abstract description 9
- 238000003384 imaging method Methods 0.000 claims description 24
- 238000003860 storage Methods 0.000 claims description 11
- 229910021417 amorphous silicon Inorganic materials 0.000 claims description 4
- 238000006243 chemical reaction Methods 0.000 claims description 3
- 239000004065 semiconductor Substances 0.000 claims description 3
- 206010034972 Photosensitivity reaction Diseases 0.000 abstract description 13
- 230000036211 photosensitivity Effects 0.000 abstract description 13
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 abstract description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 abstract description 8
- 229910052799 carbon Inorganic materials 0.000 abstract description 8
- 229910052760 oxygen Inorganic materials 0.000 abstract description 8
- 239000001301 oxygen Substances 0.000 abstract description 8
- 229910021420 polycrystalline silicon Inorganic materials 0.000 abstract description 7
- 239000012535 impurity Substances 0.000 abstract description 5
- 238000000034 method Methods 0.000 abstract description 5
- 239000007787 solid Substances 0.000 abstract description 2
- 238000004544 sputter deposition Methods 0.000 abstract description 2
- 239000000243 solution Substances 0.000 abstract 1
- 206010047571 Visual impairment Diseases 0.000 description 14
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 11
- 229910052681 coesite Inorganic materials 0.000 description 6
- 229910052906 cristobalite Inorganic materials 0.000 description 6
- 239000010410 layer Substances 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 239000000523 sample Substances 0.000 description 6
- 229910052682 stishovite Inorganic materials 0.000 description 6
- 229910052905 tridymite Inorganic materials 0.000 description 6
- LDDQLRUQCUTJBB-UHFFFAOYSA-N ammonium fluoride Chemical compound [NH4+].[F-] LDDQLRUQCUTJBB-UHFFFAOYSA-N 0.000 description 5
- 239000000377 silicon dioxide Substances 0.000 description 5
- 235000012239 silicon dioxide Nutrition 0.000 description 5
- 238000012546 transfer Methods 0.000 description 5
- 238000000151 deposition Methods 0.000 description 4
- 239000011229 interlayer Substances 0.000 description 4
- 239000012528 membrane Substances 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000005530 etching Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- -1 Mo silicide Chemical compound 0.000 description 2
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 2
- 230000000903 blocking effect Effects 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- JKQOBWVOAYFWKG-UHFFFAOYSA-N molybdenum trioxide Chemical compound O=[Mo](=O)=O JKQOBWVOAYFWKG-UHFFFAOYSA-N 0.000 description 2
- 238000001020 plasma etching Methods 0.000 description 2
- 229910052721 tungsten Inorganic materials 0.000 description 2
- 206010034960 Photophobia Diseases 0.000 description 1
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical group [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 208000013469 light sensitivity Diseases 0.000 description 1
- 238000004949 mass spectrometry Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001443 photoexcitation Effects 0.000 description 1
- 238000005268 plasma chemical vapour deposition Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Abstract
Description
【発明の詳細な説明】
［発明の目的］
（産業上の利用分野）
本発明は、固体撮像素子チップ゛に光導電体膜を積層し
て構成される積層型固体撮像装置に係わり、特に画素電
極の改良をはかった積層型固体撮像装置に関する。[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a stacked solid-state imaging device configured by stacking a photoconductor film on a solid-state imaging device chip, and particularly relates to This invention relates to a stacked solid-state imaging device with improved electrodes.
（従来の技術）
固体撮像素子チップに光導電体膜を積層した２階建て構
造の固体撮像装置は、感光部の開口面積を広くすること
ができるため、高感度且つ低スミアと云う優れた特性を
有する。このため、この固体撮像装置は、各種監視用Ｔ
Ｖや高品位ＴＶ等のカメラとして有ｔ！ｉ視されている
。この種の固体撮像装置用の光導電体膜としては、現在
のところ、アモルファス材料膜が用いられている。例え
ば、５ｃ−Ａｓ−Ｔｃ膜（サチコン膜） 、 Ｚｎ５ｃ
−ＺｎＣｄＴｃ にュービコン膜） 、 ａ−８ｔ：
ＩＩ膜（水素化非晶質シリコン膜）等である。これらの
材料の中で特に、特性や加工性の良さ、低温形成の可能
性等から、ａ−８ｌ：Ｈ膜が本命になりつつある。(Prior art) A solid-state imaging device with a two-story structure in which a photoconductor film is laminated on a solid-state imaging device chip has excellent characteristics such as high sensitivity and low smear because the aperture area of the photosensitive part can be widened. has. Therefore, this solid-state imaging device can be used for various monitoring purposes.
It can be used as a camera for V or high-definition TV! It is viewed as i. At present, an amorphous material film is used as a photoconductor film for this type of solid-state imaging device. For example, 5c-As-Tc film (Sachicon film), Zn5c
-ZnCdTc (Ubicon membrane), a-8t:
II film (hydrogenated amorphous silicon film), etc. Among these materials, the a-8l:H film is becoming the favorite because of its good properties, workability, and possibility of low-temperature formation.
ａ−８ｌ：ＩＩ膜を光導電体膜として固体撮像素子チッ
プ上に積層する場合、従来は金属画素電極がチップ最上
部に露出した状態で、この上にａ−８ｌ：１１Ｍを成膜
することが行われている（例えば、第１６回国際固体コ
ンファレンス、アブストラクト、 ｐｐ３２５〜３２８
参照）。ところが、このような構造では、画素電極と先
導電体膜との界面特性に起因する光感度の低下や残像が
大きいこと等が問題になる。When a-8l:II film is laminated as a photoconductor film on a solid-state image sensor chip, conventionally, a-8l:11M film is formed on top of the metal pixel electrode with the metal pixel electrode exposed at the top of the chip. (e.g., 16th International Solid State Conference, Abstracts, pp. 325-328).
reference). However, such a structure poses problems such as a decrease in photosensitivity and large afterimages due to the interface characteristics between the pixel electrode and the leading electric film.
また、ａ−８ｌ：Ｉ＋膜を積層する金属電極表面の状態
により光感度、残像等の特性が変動するために、再現性
良く良好な特性を示す積層型固体撮像素子を得ることが
難しい。Further, since characteristics such as photosensitivity and afterimage vary depending on the surface condition of the metal electrode on which the a-8l:I+ film is laminated, it is difficult to obtain a laminated solid-state image sensor that exhibits good characteristics with good reproducibility.
本発明者等は、この原因が金属表面に存在する酸素や炭
素等の不純物による金属電極近傍のａ−８ｌ：１１膜の
汚染であることを見出した。即ち、金属電極表面の酸素
や炭素がａ−３ｔ：Ｈ膜の成膜時にａ−８ｔ：Ｈ膜に取
り込まれるか、或いはその後に金属表面からａ−８ｌ：
ＩＩ膜に拡散して、光感度や残像等の特性を低下させる
。The present inventors have discovered that the cause of this is contamination of the a-8l:11 film near the metal electrode due to impurities such as oxygen and carbon present on the metal surface. That is, oxygen and carbon on the surface of the metal electrode are taken into the a-8t:H film during the formation of the a-3t:H film, or are subsequently absorbed from the metal surface into the a-8l:
It diffuses into the II film and reduces characteristics such as photosensitivity and afterimage.
（発明が解決しようとする問題点）
このように従来、ａ−８ｔ：ＩＩ膜を光導電体膜として
用いた積層型固体撮像装置では、画素電極の金属表面の
酸素や炭素が画素電極界面近傍のａ−８ｌ：Ｉｆ膜に取
り込まれて、光感度や残像特性等が低下すると云う問題
があった。(Problems to be Solved by the Invention) Conventionally, in a stacked solid-state imaging device using an a-8t:II film as a photoconductor film, oxygen and carbon on the metal surface of the pixel electrode are concentrated near the pixel electrode interface. a-8l: There was a problem in that it was incorporated into the If film and the photosensitivity, afterimage characteristics, etc. deteriorated.
本発明は上記事情を考慮してなされたもので、その目的
とするところは、画素電極表面の状態を良好に保持する
ことができ、光感度が大きく且つ残像値の小さい積層型
固体撮１象装置を提供することにある。The present invention has been made in consideration of the above-mentioned circumstances, and its purpose is to provide a multilayer solid-state camera that can maintain the condition of the pixel electrode surface well, has high photosensitivity, and has a low afterimage value. The goal is to provide equipment.
［発明の構成コ
（問題点を解決するための手段）
本発明の骨子は、積層型固体撮像装置における画素電極
として、表面の自然酸化膜の除去が容品な金属シリサイ
ドを用いることにある。[Structure of the Invention (Means for Solving Problems)] The gist of the present invention is to use metal silicide, from which a natural oxide film on the surface can be easily removed, as a pixel electrode in a stacked solid-state imaging device.
即ち本発明は、半導体基板に信号電荷蓄積ダイオードと
信号電荷読出し部が配列され、最上部に信号電荷蓄積ダ
イオードに電気的に接続された画素電極が形成された固
体撮像素子チップと、このチップ上に光電変換部として
積層された水素化非晶質シリコン膜からなる光導電体膜
とを具備した積層型固体撮像装置において、前記固体撮
像素子チップ上の画素電極の少なくとも前記光導電体膜
と接する部分を、自然酸化膜として５ｉＱ２が優先的に
形成され、几っＳｉＯ２のエッチャントに対して耐性の
ある金属シリサイドにより構成するようにしたものであ
る。That is, the present invention provides a solid-state image sensor chip in which a signal charge storage diode and a signal charge readout section are arranged on a semiconductor substrate, and a pixel electrode electrically connected to the signal charge storage diode is formed on the top, and In a stacked solid-state imaging device comprising a photoconductor film made of a hydrogenated amorphous silicon film stacked as a photoelectric conversion portion on a semiconductor device, at least a pixel electrode on the solid-state image sensor chip is in contact with the photoconductor film. The portion is made of metal silicide in which 5iQ2 is preferentially formed as a natural oxide film and is resistant to SiO2 etchant.
（作 用）
本発明によれば、画素電極の表面部としてＭｏシリサイ
ド、Ｗシリサイド、Ｃｒシリサイド等のＨＦやＮＨ４Ｆ
の水溶液により表面の酸化膜を除去可能な金属シリサイ
ドを用いることにより、この上に形成する光導電膜であ
るａ−８１：Ｈ膜と画素７ば極との界面の酸化膜を容易
に除去することができる。従って、光感度、残像の特性
の良好な固体撮像装置を再現性良く実現することが可能
となる。(Function) According to the present invention, HF or NH4F such as Mo silicide, W silicide, or Cr silicide is used as the surface portion of the pixel electrode.
By using metal silicide whose surface oxide film can be removed with an aqueous solution, the oxide film at the interface between the a-81:H film, which is the photoconductive film formed thereon, and the pixel 7 electrode can be easily removed. be able to. Therefore, it is possible to realize a solid-state imaging device with good light sensitivity and afterimage characteristics with good reproducibility.
こＺＴ、Ｗ、Ｃｒ、Ｍｏ等のシリサイドはＨＦやＮＨ４
Ｆの水溶液により自然酸化膜を容易に除去できるとして
いるが、その理由を以下の通りである。Ｓ （、Ｍｏ、
Ｗ、Ｃｒの酸化物の生成エネルギーの大小関係は
Ｓ ｉ ０２ ＞ＷＯｑ ＞Ｍｏｂ、＞Ｃｒｏｑとなっ
ているために、Ｍｏシリサイド、Ｗシリサイド、Ｃｒシ
リサイド等を酸化すると、ＭｏＯ３゜ＷＯ３，ＣｒＯ３
でな（Ｓｉ０２が優先的に形成される。実際、Ｍｏシリ
サイドを熱酸化するとＭ ｏ Ｏ３でなくＳｉＯ２か形
成されることが文献（Ｊｏｕｎａｌ ｏｆ’ ｔｈｅ
Ｉ’：Ｉｅｃｔｒｏ Ｃｈｅｍｉｃａｌ ５ｏｃｉｅｔ
ｙｖｏ１．ｌＩ２ （１９６５） Ｐ２Ｓ５〜５８９
）に報告されている。従って、Ｍｏシリサイド、Ｗシリ
サイド。Silicides such as ZT, W, Cr, and Mo are HF and NH4.
It is said that the natural oxide film can be easily removed with an aqueous solution of F, and the reason for this is as follows. S (,Mo,
Since the magnitude relationship of the formation energies of W and Cr oxides is S i 02 > WOq > Mob, > Croq, when Mo silicide, W silicide, Cr silicide, etc. are oxidized, MoO3゜WO3, CrO3
(Si02 is preferentially formed.In fact, it is reported in the Journal of the
I': Electro Chemical 5ociet
yvo1. lI2 (1965) P2S5~589
) has been reported. Therefore, Mo silicide, W silicide.
Ｃｒシリサイドの自然酸化膜も当然ＳｉＯ２である。Ｓ
ｉＯ２であれば、ＨＦやＮＨ４Ｆの水溶液で８易に除去
することができる。Naturally, the natural oxide film of Cr silicide is also SiO2. S
If it is iO2, it can be easily removed with an aqueous solution of HF or NH4F.
一方、Ｍｏシリサイド、Ｗシリサイド、Ｃｒシリサイド
は多結晶シリコンと同様に、ＨＦ。On the other hand, Mo silicide, W silicide, and Cr silicide are HF similar to polycrystalline silicon.
ＮＨ４Ｆの水溶液に耐エツチング性がある。従って、Ｍ
ｏシリサイド、Ｗシリサイド、Ｃｒシリサイドにおいて
は、表面の自然酸化膜をＨＦやＮＨ４Ｆの水溶液で処理
して容易に除去することができる。また、酸化物がＳｉ
Ｏ２よりも生成エネルギーが小さい金属であるならば、
このような金属シリサイドを画素電極として用いること
が可能である。なお、画素電極として多結晶シリコンを
用いたのでは、画素電極を光が透過してしまい、基板内
部にキャリアが発生しスミア発生の問題となる。金属シ
リサイドであれば、このような問題はない。An aqueous solution of NH4F has etching resistance. Therefore, M
In o-silicide, W-silicide, and Cr-silicide, the natural oxide film on the surface can be easily removed by treatment with an aqueous solution of HF or NH4F. Also, the oxide is Si
If it is a metal whose production energy is smaller than O2,
Such metal silicide can be used as a pixel electrode. Note that if polycrystalline silicon is used as the pixel electrode, light will pass through the pixel electrode, and carriers will be generated inside the substrate, causing a problem of smear generation. Metal silicide does not have this problem.
（実施例） 以下、本発明の詳細を図示の実施例によって説明する。(Example) Hereinafter, details of the present invention will be explained with reference to illustrated embodiments.
第１図は本発明の一実施例に係わる積層型ＣＣＤ撮像装
置の概略構造を示す断面図である。FIG. 1 is a sectional view showing a schematic structure of a stacked CCD imaging device according to an embodiment of the present invention.
ｐ十型Ｓｉ基板１１上にｐウェル１２が形成されたウェ
ーハを用いて、インターライン転送型ＣＣＤ撮像索子チ
ップ１が構成されている。即ち、信号電荷を蓄積する蓄
積ダイオード１３がマトリックス状に形成され、蓄積ダ
イオード１３の列に隣接してｎ十型の埋込みチャネルＣ
ＯＤからなる垂直ＣＣＤ１４が形成されている。１５は
チャネルやストッパとしてのｐ十型層であり、これによ
り分離されて同様の構成の蓄積ダイオード列と垂直ＣＣ
Ｄの組が繰返し配列形成される。An interline transfer type CCD imaging probe chip 1 is constructed using a wafer in which a p-well 12 is formed on a p-type Si substrate 11. That is, storage diodes 13 for storing signal charges are formed in a matrix, and n+ type buried channels C are adjacent to the rows of storage diodes 13.
A vertical CCD 14 made of OD is formed. 15 is a p-type layer as a channel and a stopper, which separates the storage diode array and the vertical CC of the same configuration.
A set of D is formed in a repeating array.
１６１．１６２は垂直ＣＣＤ１４の転送ゲート電極であ
り、その一部は蓄積ダイオード１３からＣＣＤチャネル
への電荷転送ゲート電極を兼ねている。転送ゲート電極
１６１，１６２が形成された基板上は層間絶縁膜１８．
．１．８２に覆われ、且つ蓄積ダイオード１３に接続さ
れる多結晶シリコン電極１７が形成されて、平坦化され
ている。161 and 162 are transfer gate electrodes of the vertical CCD 14, a part of which also serves as a charge transfer gate electrode from the storage diode 13 to the CCD channel. An interlayer insulating film 18 is formed on the substrate on which the transfer gate electrodes 161 and 162 are formed.
．． 1.82 and connected to the storage diode 13 is formed and planarized.
第１の層間絶縁膜１８１は例えばＣＶＤによるＳｉＯ２
膜であり、第２の層間絶縁膜１８２はプラズマＣＶＤに
よるＢＰＳＣ膜である。この構造は、多結晶シリコン膜
電極１７を各蓄積ダイオード１３上に立てた後、ＢＰＳ
Ｃ；膜を被着してこれを溶融し、反応性イオンエツチン
グ法でＢＰＳＣ膜をエツチングして多結晶シリコン電極
１７の表面を露出させることで得られる。The first interlayer insulating film 181 is made of, for example, SiO2 by CVD.
The second interlayer insulating film 182 is a BPSC film formed by plasma CVD. In this structure, after a polycrystalline silicon film electrode 17 is erected on each storage diode 13, the BPS
C: Obtained by depositing a film, melting it, and etching the BPSC film using a reactive ion etching method to expose the surface of the polycrystalline silicon electrode 17.
このように表面が平坦化されたＣＣＤ撮像索子チップ１
上に、各多結晶シリコン電極１７に接続される画素電極
１９が形成されている。この画素電極１９は、スパッタ
リング法によりＭｏシリサイド膜を全面に被着した後に
、反応性イオンエツチング法でエツチングして所定の形
状に形成される。画素電極１９が形成されたチップ基板
上には、光導電体膜２が積層形成される。このとき、光
導電体膜２を形成する直前に、３％のＨＦの水溶液によ
り３０秒間浸して処理することにより、画素電極３上の
Ｍｏシリサイド膜の熱酸化膜を除去し、その直後に光導
電体膜２を形成する。これにより、画素電極１９の表面
の酸素や炭素等の不純物が効果的に除去され、画素電極
１９と光導電体膜２との界面が良好なものとなる。CCD imaging probe chip 1 with a flattened surface in this way
A pixel electrode 19 connected to each polycrystalline silicon electrode 17 is formed thereon. The pixel electrode 19 is formed into a predetermined shape by depositing a Mo silicide film over the entire surface by sputtering and then etching by reactive ion etching. A photoconductor film 2 is laminated on the chip substrate on which the pixel electrode 19 is formed. At this time, immediately before forming the photoconductor film 2, the thermal oxidation film of the Mo silicide film on the pixel electrode 3 is removed by immersion treatment in a 3% HF aqueous solution for 30 seconds, and immediately after that, the Mo silicide film is exposed to light. A conductor film 2 is formed. As a result, impurities such as oxygen and carbon on the surface of the pixel electrode 19 are effectively removed, and the interface between the pixel electrode 19 and the photoconductor film 2 becomes good.
光導電体膜２は、正孔注入阻止層としてのｉ型のａ−８
ＩＣ：ＩＩ膜（水素化アモルファスシリコン台カーバイ
ド）膜２１、主として光電変換が行われる高抵抗のａ−
８１：Ｉｔ膜２２及び電子注入阻止層となるｐ型のａ−
８ＩＣ：Ｈ膜２３の３層構造からなる。これらの膜は、
ＳｉＨ４ガスを主成分とするガスのグロー放電分解法に
より形成される。ａ−８ＩＣ：Ｈ膜２１は、暗導電率Ｕ
ｏ 〜１Ｏ−Ｉ４／Ωｃｍで厚さ １００λ程度とす
る。高抵抗ａ−８１：Ｉｆ膜２２は、暗導電率σ〜１０
−１２／Ωｃｍで光電変換に必要な十分な厚さとする。The photoconductor film 2 is an i-type a-8 film as a hole injection blocking layer.
IC: II film (hydrogenated amorphous silicon carbide) film 21, a high-resistance a-
81: p-type a- which becomes the It film 22 and electron injection blocking layer
It consists of a three-layer structure of 8IC:H film 23. These membranes are
It is formed by a glow discharge decomposition method of a gas whose main component is SiH4 gas. a-8IC:H film 21 has dark conductivity U
o ~1O-I4/Ωcm and a thickness of about 100λ. High resistance a-81: If film 22 has dark conductivity σ~10
The thickness is -12/Ωcm, which is sufficient for photoelectric conversion.
ｐ型ａ−８ＩＣ：ＩＩ膜２３は約２０００程度とする。The thickness of the p-type a-8 IC:II film 23 is approximately 2000.
このように形成された光導電体膜２上に透明電極として
、例えばＩＴＯ電極２４が形成されている。For example, an ITO electrode 24 is formed as a transparent electrode on the photoconductor film 2 formed in this manner.
このようにして形成されたＣＣＤ撮像装置の光感度と残
像を７１−１定した。ＣＣＤ撮像素子チップとしては、
２０万画素、２ノ３インチサイズのものを用い、光導電
体膜の実効電界強度を１ ｘ １０’ Ｖ／ａｍとした
。残像測定では信号電流１００ｎＡとなるように光量を
調整した。下記表に、測定結果を従来の電極を用いたも
のと、Ｍｏシリサイド電極でＨＦ水溶液処理有りと無し
との３つのサンプルについて示した。なお、光感度はサ
ンプル１の値で規格化して示した。残像値は３フイール
ドの値である。The photosensitivity and afterimage of the CCD imaging device thus formed were determined in 71-1. As a CCD image sensor chip,
A photoconductor with 200,000 pixels and a size of 2 to 3 inches was used, and the effective electric field strength of the photoconductor film was set to 1 x 10' V/am. In the afterimage measurement, the light intensity was adjusted so that the signal current was 100 nA. The table below shows the measurement results for three samples: one using a conventional electrode and one using a Mo silicide electrode with and without HF aqueous solution treatment. Note that the photosensitivity was normalized to the value of Sample 1 and shown. The afterimage value is a value of 3 fields.
この表から判るように、画素電極１９がＭｏシリサイド
電極でＨＦ処理無しとＴｉ電極の場合は、光感度と残像
値は略同じである。これに対して、Ｍｏシリサイド電極
でＨＦ処理Ｈりの場合は、光感度が大きくなり、残像値
が小さくなっていることが判る。Ｍｏシリサイド電極で
ＨＦ処理した場合は、画素電極１つの表面の酸化膜がａ
−８ｌ：ＩＩ膜の堆積の直前に除去されるため、画素電
極１９の表面とａ−８ｉ：ＩＩ膜の界面の酸素や炭素が
減少し、これにより光感度が大きく残像が小さくなるの
である。As can be seen from this table, the photosensitivity and afterimage value are approximately the same when the pixel electrode 19 is a Mo silicide electrode without HF treatment and when it is a Ti electrode. On the other hand, it can be seen that when the Mo silicide electrode is subjected to HF treatment H, the photosensitivity is increased and the afterimage value is decreased. When a Mo silicide electrode is subjected to HF treatment, the oxide film on the surface of one pixel electrode becomes a
Since it is removed immediately before the -8l:II film is deposited, oxygen and carbon at the interface between the surface of the pixel electrode 19 and the a-8i:II film are reduced, thereby increasing the photosensitivity and reducing the afterimage.
実際、表のサンプルとそれぞれ同等の処理を施したＭｏ
シリサイドとＴｉの上に堆積したａ−８１：ｉｔ膜を２
次イオン質量分析（ＳＩＭＳ）によって不純物の膜厚方
向の分布を調べたところ、Ｍｏシリサイド電極でＨＦ処
理をした場合には、Ｍｏシリサイド電極でＨＦ処理なし
の場合或いはＴｉ電極の場合に比べて、電極表面近傍の
ａ−８ｔ：Ｈ膜に含まれる酸素と炭素の瓜が少ないこと
を確認した。さらに、ＷシリサイドやＣｒシリサイドの
場合も、Ｍｏシリサイドと同様の結果が得られるのを確
認した。即ち、Ｍ ｏシリサイド、Ｗシリサイド。In fact, Mo
A-81:IT film deposited on silicide and Ti
Next, when we investigated the distribution of impurities in the film thickness direction using ion mass spectrometry (SIMS), we found that when a Mo silicide electrode was subjected to HF treatment, compared to a Mo silicide electrode without HF treatment or a Ti electrode. It was confirmed that the amount of oxygen and carbon contained in the a-8t:H film near the electrode surface was small. Furthermore, it was confirmed that the same results as with Mo silicide can be obtained with W silicide and Cr silicide. That is, Mo silicide, W silicide.
Ｃｒシリサイド等の酸化膜除去可能な材料を画素電極１
９に用いると、光導電体膜２であるａ−３ｔ：ＩＩ膜の
堆積直前に画素電極１９の表面の酸化膜を除去すること
で、画素電極１９の表面が洗浄化され、画素電極１９の
表面近傍のａ−８ｔ：ＩＩ模膜中酸素や炭素等の不純物
が減少して、光感度が大きく残像値が小さくなるのであ
る。The pixel electrode 1 is made of a material that can remove the oxide film, such as Cr silicide.
9, the surface of the pixel electrode 19 is cleaned by removing the oxide film on the surface of the pixel electrode 19 immediately before depositing the a-3t:II film that is the photoconductor film 2, and the surface of the pixel electrode 19 is cleaned. Impurities such as oxygen and carbon in the a-8t:II model film near the surface are reduced, resulting in increased photosensitivity and reduced afterimage value.
なお、本発明は上述した実施例に限定されるものではな
い。実施例ではＣＣＤ撮像索子を用いたが、ＭｏＳ型や
ＢＢＤ型撮像索子チップを用いてこれにａ−３ｌ ：
Ｈ光導電体膜を積層する場合にも、本発明を同様に適用
することができる。さらに、ａ−８ｌ二Ｉｔ光導電体膜
の製法も、実施例のものに限らず、例えば光励起膜形成
法により形成してもよい。Note that the present invention is not limited to the embodiments described above. In the example, a CCD imaging probe was used, but a MoS type or BBD type imaging probe chip was used for this a-3l:
The present invention can be similarly applied to the case of laminating H photoconductor films. Furthermore, the method for producing the a-8l2It photoconductor film is not limited to that of the embodiments, and may be formed by, for example, a photoexcitation film forming method.
また、光導電体膜はａ−８ｉ ： Ｈ膜が主体であれば
よく、ａ−９ＩＣ：１１ 、 ａ−８ＩＧｅ：！ｌ、
ａ−８ｉＮ：Ｈ、ａ−８ＩＳｎ：Ｈ，更にこれらのＦを
含有するものを用いた場合にも本発明は有効である。Further, the photoconductor film may be mainly composed of a-8i:H film, such as a-9IC:11, a-8IGe:! l,
The present invention is also effective when using a-8iN:H, a-8ISn:H, and those containing F.
また、実施例では画素電極を１層の金属シリサイドによ
り構成したが、製造プロセス上に画素電極の膜剥がれの
問題が生じる場合には、金属シリサイドの下に被着性の
良好な導電膜を挿入して、画素電極を２層から構成して
もよい。さらに、画素電極としての金属シリサイドは、
Ｍｏ、Ｗ。In addition, in the example, the pixel electrode was constructed from a single layer of metal silicide, but if the problem of pixel electrode film peeling occurs during the manufacturing process, a conductive film with good adhesion is inserted under the metal silicide. Thus, the pixel electrode may be composed of two layers. Furthermore, metal silicide as a pixel electrode is
Mo, W.
Ｃｒのシリサイドに限るものではなく、自然酸化膜とし
てＳｉＯ２が優先的に形成され、且つＳｉＯ２のエッチ
ャントであるＨＦやＮＨ４Ｆ等の水溶液に対して十分な
耐性のあるものであればよい。その他、本発明の要旨を
逸脱しない範囲で、種々変形して実施することができる
。The material is not limited to Cr silicide, but any material may be used as long as it preferentially forms SiO2 as a natural oxide film and has sufficient resistance to aqueous solutions such as HF and NH4F, which are SiO2 etchants. In addition, various modifications can be made without departing from the gist of the present invention.
［発明の効果］
以上詳述したように本発明によれば、光導電体膜として
のａ−８ｔ：ｉｆ膜に接する画素電極の少なくとも表面
部にＭｏシリサイド、Ｗシリサイド。[Effects of the Invention] As detailed above, according to the present invention, Mo silicide and W silicide are formed on at least the surface portion of the pixel electrode in contact with the a-8t:if film as a photoconductor film.
Ｃｒシリサイド等の表面酸化膜を除去可能な材料を画素
電極として用いることにより、画素電極表面をａ−８ｉ
： Ｈ膜堆積直前に効果的に洗浄することができ、光
感度が大き（残像値の小さい積層型固体撮像装置を実現
することができる。By using a material that can remove the surface oxide film, such as Cr silicide, for the pixel electrode, the pixel electrode surface can be made into an a-8i
: Effective cleaning can be performed immediately before H film deposition, and a stacked solid-state imaging device with high photosensitivity (low afterimage value) can be realized.
第１図は本発明の一実施例に係わる積層型ＣＣＤ撮象装
置の概略構造を示す断面図である。
１・・・ＣＣＤ撮像索子チップ、２・・・光導電体膜、
１１・・・ｐ十型Ｓｔ基板、１２・・・ｐウェル、１３
・・・蓄積ダイオード、１４・・・垂直ＣＣＤ、１．５
・・・ｐ＋型層、１６１，１６２・・・転送ゲート電極
、１７・・・ｎ十型多結晶シリコン電極、１８１，１８
２・・・層間絶縁膜、１９・・・画素電極、２１・・・
ｉ型ａ−８ＩＣ二ＩＩ膜、２２ 、、、高抵抗ａ−８ｉ
：ＩＩ膜、２３−・−ｐ型ａ−８１Ｃ：Ｉｆ膜、２４・
・・ＩＴＯ膜。FIG. 1 is a sectional view showing a schematic structure of a stacked CCD imaging device according to an embodiment of the present invention. 1... CCD imaging probe chip, 2... Photoconductor film,
11...p ten-type St substrate, 12...p well, 13
...Storage diode, 14...Vertical CCD, 1.5
... p + type layer, 161, 162 ... transfer gate electrode, 17 ... n-type polycrystalline silicon electrode, 181, 18
2... Interlayer insulating film, 19... Pixel electrode, 21...
I type a-8 IC II film, 22,, high resistance a-8i
:II membrane, 23-・-p type a-81C: If membrane, 24・
...ITO film.
Claims (2)
読出し部が配列され、最上部に信号電荷蓄積ダイオード
に電気的に接続された画素電極が形成された固体撮像素
子チップと、このチップ上に光電変換部として積層され
た水素化非晶質シリコン膜からなる光導電体膜とを具備
した積層型固体撮像装置において、前記固体撮像素子チ
ップ上の画素電極の少なくとも前記光導電体膜と接する
部分を、自然酸化膜としてＳｉＯ＿２が優先的に形成さ
れる金属シリサイドにより構成したことを特徴とする積
層型固体撮像装置。(1) A solid-state image sensor chip in which a signal charge storage diode and a signal charge readout section are arranged on a semiconductor substrate, a pixel electrode electrically connected to the signal charge storage diode is formed on the top, and a photoelectric sensor is mounted on this chip. In a stacked solid-state imaging device comprising a photoconductor film made of stacked hydrogenated amorphous silicon films as a conversion section, at least a portion of a pixel electrode on the solid-state imaging element chip that is in contact with the photoconductor film is provided. A stacked solid-state imaging device characterized in that it is constructed of metal silicide in which SiO_2 is preferentially formed as a natural oxide film.
イド又はＣｒシリサイドであり、前記ＳｉＯ＿２のエッ
チャントはＨＦ又はＮＨ＿４Ｆの水溶液であることを特
徴とする特許請求の範囲第１項記載の積層型固体撮像装
置。(2) The stacked solid-state imaging device according to claim 1, wherein the metal silicide is Mo silicide, W silicide, or Cr silicide, and the etchant for SiO_2 is an aqueous solution of HF or NH_4F.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62297965A JPH01138752A (en) | 1987-11-26 | 1987-11-26 | Laminated solid-state image sensing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62297965A JPH01138752A (en) | 1987-11-26 | 1987-11-26 | Laminated solid-state image sensing device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01138752A true JPH01138752A (en) | 1989-05-31 |
Family
ID=17853381
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62297965A Pending JPH01138752A (en) | 1987-11-26 | 1987-11-26 | Laminated solid-state image sensing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01138752A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1113499A2 (en) * | 1999-12-28 | 2001-07-04 | Xerox Corporation | High fill factor image array having a continuous amorphous silicon sensor layer and a doped poly-silicon back contact |
| JPWO2012176390A1 (en) * | 2011-06-23 | 2015-02-23 | パナソニック株式会社 | Solid-state imaging device |
-
1987
- 1987-11-26 JP JP62297965A patent/JPH01138752A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1113499A2 (en) * | 1999-12-28 | 2001-07-04 | Xerox Corporation | High fill factor image array having a continuous amorphous silicon sensor layer and a doped poly-silicon back contact |
| EP1113499A3 (en) * | 1999-12-28 | 2003-04-16 | Xerox Corporation | High fill factor image array having a continuous amorphous silicon sensor layer and a doped poly-silicon back contact |
| JPWO2012176390A1 (en) * | 2011-06-23 | 2015-02-23 | パナソニック株式会社 | Solid-state imaging device |
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