JPS6110271A - Semiconductor device - Google Patents

Semiconductor device

Info

Publication number
JPS6110271A
JPS6110271A JP60093606A JP9360685A JPS6110271A JP S6110271 A JPS6110271 A JP S6110271A JP 60093606 A JP60093606 A JP 60093606A JP 9360685 A JP9360685 A JP 9360685A JP S6110271 A JPS6110271 A JP S6110271A
Authority
JP
Japan
Prior art keywords
film
conductive film
memory cell
insulating film
capacitor
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
Application number
JP60093606A
Other languages
Japanese (ja)
Other versions
JPH0321103B2 (en
Inventor
Mitsumasa Koyanagi
光正 小柳
Kikuji Sato
佐藤 喜久治
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP60093606A priority Critical patent/JPS6110271A/en
Publication of JPS6110271A publication Critical patent/JPS6110271A/en
Publication of JPH0321103B2 publication Critical patent/JPH0321103B2/ja
Granted legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H10SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10BELECTRONIC MEMORY DEVICES
    • H10B12/00Dynamic random access memory [DRAM] devices
    • H10B12/30DRAM devices comprising one-transistor - one-capacitor [1T-1C] memory cells
    • H10B12/31DRAM devices comprising one-transistor - one-capacitor [1T-1C] memory cells having a storage electrode stacked over the transistor

Landscapes

  • Semiconductor Memories (AREA)
  • Semiconductor Integrated Circuits (AREA)

Abstract

PURPOSE:To improve the integration of MOS memories by reducing the area of a memory cell by a method wherein an accumulation capacitor is provided so as to at least overlap on a switching transistor. CONSTITUTION:A capacitor 2 to accumulate information is so arranged as to overlap on the switching transistor 1 with each other. For example, the second polycrystalline Si 14, an insulation film 16, and the third polycrystalline Si 15 constitute the accumulation capacitor 2. In this case, a large capacitor can be obtained by using a film of large dielectric constant such as an Si3N4 or a Ta2O5 film in addition to an SiO2 film or a multilayer insulation film of the combination thereof as the insulation film 16. Therefore, in the case of obtaining the same value as that of the accumulation capacitor used in the conventional memory cell, even a small area may be satisfactory.

Description

【発明の詳細な説明】 〔発明の利用分野〕 本発明は、半導体装置の高集積化に関するもので、特に
情報蓄積用の容量の一部がスイッチングトランジスタの
上方に重なるように形成された半導体記憶装置に関する
ものである。
[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to high integration of semiconductor devices, and in particular to a semiconductor memory formed so that a part of a capacitor for information storage overlaps above a switching transistor. It is related to the device.

〔発明の背景〕[Background of the invention]

従来知られている1トランジスタ型MOSランダム・ア
クセス・メモリは第3図に平面図を、第4図にY方向断
面図(メモリセル1ビツト分)に示したように、スイッ
チングのだめのMOSトランジスタ1と情報を記憶する
ための容量2よりなるメモリセルをワード線(AQ線)
3とデータ線(拡散層)4によって選択するようになっ
ている。
A conventionally known one-transistor type MOS random access memory has a MOS transistor 1 for switching, as shown in a plan view in Fig. 3 and a cross-sectional view in the Y direction (for one bit of memory cell) in Fig. A memory cell consisting of a capacity 2 for storing information is called a word line (AQ line).
3 and a data line (diffusion layer) 4.

第3図、第4図において5は基板、6は素子間分離用の
絶縁縁膜、7はゲート酸化膜、8,12は第1層多結晶
シリコン、9は層間絶膜、4,10は拡散層、11は反
転層、22はコンタクト孔である。
In FIGS. 3 and 4, 5 is a substrate, 6 is an insulating film for isolation between elements, 7 is a gate oxide film, 8 and 12 are first layer polycrystalline silicon, 9 is an interlayer insulation film, and 4 and 10 are A diffusion layer, 11 an inversion layer, and 22 a contact hole.

図かられかるにうに、情報を蓄積するための容量2はス
イッチングトランジスタ1と互いに重ならないように同
一平面に2次元的に配置されているために、メモリ・セ
ルのセル面積が大きくなる。
As can be seen from the figure, since the capacitor 2 for storing information is two-dimensionally arranged on the same plane as the switching transistor 1 so as not to overlap with each other, the cell area of the memory cell increases.

〔発明の目的〕[Purpose of the invention]

本発明の目的は上記従来の問題を解析し、所要面積の極
めて小さい半導体装置を提供することである。
An object of the present invention is to analyze the above-mentioned conventional problems and provide a semiconductor device with an extremely small required area.

〔発明の構成〕[Structure of the invention]

本発明は蓄積容量の少なくとも一部をスイッチング ・
 トランジスタの上方に重なるように設けることによっ
て、 メモリセル面積を少なくし、MOSメモリの集積
度を向上することを可能とするものである。
The present invention switches at least a portion of the storage capacity.
By providing it so as to overlap above the transistor, it is possible to reduce the memory cell area and improve the degree of integration of the MOS memory.

〔発明の実施例〕[Embodiments of the invention]

以下、本発明を実施例を参照して詳細に説明する。 Hereinafter, the present invention will be explained in detail with reference to Examples.

第1図および第2図に本発明による半導体記憶装置の一
例を平面図および断面図で示す(メモリセル2−ビット
分)。図かられかるように1本発明においては比抵抗1
5Ω・cm、結晶軸方向<100>の■〕形シリコン基
板5の一部に1.5μmの厚さの素子分離用酸化膜6,
800人の厚さのゲーh S ]、 O2膜7、膜厚5
00人、層抵抗15Ω10の第1多結晶シリコン・ゲー
ト電極12、接合深さ1.5μmで層抵抗10/口のソ
ースおよびトレイン領域10,13.4000人の厚さ
のSio2膜19膜設9た後、 コンタクト孔18を通
して不純物添加領域(拡散領域)】0に接するように膜
厚5000人、層抵抗30Ω/口の第2多結晶シリコン
電極】4を形成する。更に絶縁膜16および膜厚500
0人5層抵抗15Ω10の第3多結晶シリコン電極15
を形成し、8000人の厚さのりんガラス(P206濃
度2mole%)9を堆積した後、コンタクト孔17を
設け、AQ電極41を形成する。なお、第1図および第
2図において、第2多結晶シリコン14、絶縁膜16、
第3多結晶シリコン15は蓄積容量を構成している。ま
た、この場合、絶縁膜16としては5i02膜以外に 
Si3N4膜、Ta206膜の如き誘電率の大きな膜あ
るいはこれらを組み合せた多層絶縁膜を使用することに
より大きな蓄積容量を得ることができる。従って、従来
のメモリセルで用いられている蓄積容量と同一の値を得
る場合、その面積は少なくてすむ。たとえば、絶縁膜と
して800人のSio2膜、 Si3N4膜、Ta20
5膜を用いた場合、コンタクト孔寸法2μm、マスク合
わせ余裕2μm、多結晶シリコンゲート幅6μm、不純
物添加層(拡散層)幅6μm、蓄積容量0.22 p 
Fとすると、1ビツトあたりのメモリセル面積は、それ
ぞれ、725μm2゜297μm2.192μm2とな
る。この面積はそれぞれ同じ設計値を用いて製作した従
来型メモリセル面積925μm2の78%、 32%、21%である。
FIGS. 1 and 2 show a plan view and a cross-sectional view of an example of a semiconductor memory device according to the present invention (2 bits of memory cells). As can be seen from the figure, in the present invention, the specific resistance is 1
An oxide film 6 for element isolation with a thickness of 1.5 μm is formed on a part of the silicon substrate 5 having a thickness of 5Ω·cm and a <100> crystal axis direction.
800 people thick game h S ], O2 film 7, film thickness 5
A first polysilicon gate electrode 12 with a layer resistance of 15 Ω and a junction depth of 1.5 μm and a source and train region of 10 Ω and a layer resistance of 10 Ω, 13.4000 Ω thick SiO2 film 19, After that, a second polycrystalline silicon electrode 4 having a film thickness of 5000 mm and a layer resistance of 30 Ω/gate is formed so as to be in contact with the impurity doped region (diffusion region) 0 through the contact hole 18. Furthermore, an insulating film 16 and a film thickness of 500
0 people 5 layers 3rd polycrystalline silicon electrode 15 with resistance 15Ω10
After depositing phosphor glass (P206 concentration 2 mole %) 9 to a thickness of 8,000, contact holes 17 are formed and AQ electrodes 41 are formed. Note that in FIGS. 1 and 2, the second polycrystalline silicon 14, the insulating film 16,
The third polycrystalline silicon 15 constitutes a storage capacitor. In addition, in this case, the insulating film 16 is other than the 5i02 film.
A large storage capacity can be obtained by using a film with a high dielectric constant such as a Si3N4 film or a Ta206 film, or a multilayer insulating film that is a combination of these films. Therefore, in order to obtain the same storage capacitance as that used in conventional memory cells, the area required is smaller. For example, 800 Sio2 films, Si3N4 films, Ta20 films are used as insulating films.
When using 5 films, the contact hole size is 2 μm, the mask alignment margin is 2 μm, the polycrystalline silicon gate width is 6 μm, the impurity doped layer (diffusion layer) width is 6 μm, and the storage capacity is 0.22 p.
Assuming that F, the memory cell area per one bit is 725 .mu.m2 and 297 .mu.m2.192 .mu.m2. These areas are 78%, 32%, and 21% of the conventional memory cell area of 925 μm 2 manufactured using the same design values, respectively.

本実施例で示したメモリセルへの情報の書き込み、読み
出しは次のように行う。すなわち、第3多結晶シリコン
電極15を接地電位に固伝した後、第1多結晶シリコン
より成るワード線31に圧電圧をを印加することにより
スイッチングトランジスタ1を導通させる。その後、A
Qより成るデータ線4】に“0”またはrr i ++
に相当する電圧を印加することにより、蓄積容量2に情
報となる電荷を蓄積する。情報の読み出しはスイッチン
グトランジスタ1を導通させた後、データ線41の電位
変化を検出することによって行われる。本発明のメモリ
セルにおいては、蓄積容量を形成するのに反転層を用い
ていないため、それに基づくリーク電流が流れない。従
って、記憶情報保持時間が著く長くなるという利点があ
る 第5図および第6図に本発明の他の実施例について平面
図と断面図(メモリセル2ビツト分)を示す。図かられ
かるように本実施例においては、不純物添加領域(拡散
領域)10.13と第2多結晶シリコン電極14および
AΩ電極41を接触させるためのコンタクト孔18.1
7を自己整合で形成している。このような自己整合によ
るコンタクト孔の形成は本発明者等が先に出願した特願
昭50−111622号明細書に詳しく示されている。
Writing and reading information to and from the memory cell shown in this embodiment is performed as follows. That is, after the third polycrystalline silicon electrode 15 is fixed to the ground potential, a piezoelectric voltage is applied to the first polycrystalline silicon word line 31 to make the switching transistor 1 conductive. After that, A
“0” or rr i ++ on the data line 4 consisting of Q
By applying a voltage corresponding to , charges serving as information are stored in the storage capacitor 2. Reading of information is performed by turning on the switching transistor 1 and then detecting a change in the potential of the data line 41. In the memory cell of the present invention, since an inversion layer is not used to form a storage capacitor, no leakage current flows due to the inversion layer. Therefore, FIGS. 5 and 6 show a plan view and a cross-sectional view (for 2 bits of memory cells) of another embodiment of the present invention, which has the advantage that the storage information retention time is significantly longer. As can be seen from the figure, in this embodiment, a contact hole 18.1 for bringing the impurity doped region (diffusion region) 10.13 into contact with the second polycrystalline silicon electrode 14 and the AΩ electrode 41 is used.
7 is formed by self-alignment. Formation of contact holes by such self-alignment is described in detail in Japanese Patent Application No. 111622/1982, previously filed by the present inventors.

自己整合コンタクト方式を採用することにより、本発明
を用いる利点が更に顕著になる。たとえば、絶縁膜16
として800人(7)Si02膜、Si3N4膜、Ta
zOslllを使用し、前述の設計値に基づいて本実施
例のメモリを製作するとメモリ面積はそれぞれ675μ
m2,275μm2,176μm2となる。 この面積
は、 それぞれ、 同じ設計値を用いて製作した従来型
メモリのメモリセル面積925μm2の73%、29%
、19%である。
By employing a self-aligned contact method, the advantages of using the present invention become even more pronounced. For example, the insulating film 16
800 people (7) Si02 film, Si3N4 film, Ta
When the memory of this example is manufactured using zOsllll based on the above-mentioned design values, the memory area is 675μ.
m2, 275 μm2, 176 μm2. These areas are 73% and 29%, respectively, of the memory cell area of 925 μm2 for conventional memory fabricated using the same design values.
, 19%.

第7図および第8図に本発明の他の実施例について平面
図と断面図を示す(メモリセル2ビツト分)。本実施例
においては図に示すようにX方向くデータ線方向)の素
子分離を800人のSiO2膜21上21上した第1多
結晶シリコン2oに負電圧を印加すること(フィールド
・シールドと記す)により行っている。フィールド・シ
ールド方法についてはすでに公知の文献に詳しく述べら
れている。自己整合コンタクトおよびフィールド・シー
ルド方法を採用することにより、本発明を用いる利点が
更に顕著になる。すなわち、局所酸化により−C素r分
離用酸化膜を形成する場合に生しるような横方向酸化(
バード・ピーク)によるコンタク1〜孔寸法の変化、お
よび素子分離用酸化膜端部での結晶欠陥などに基づくリ
ーク電流が少なくなり、自己整合コンタクト方法が容易
になる。
FIGS. 7 and 8 show a plan view and a sectional view of another embodiment of the present invention (for 2 bits of memory cells). In this example, as shown in the figure, device isolation in the X direction (data line direction) is achieved by applying a negative voltage to the first polycrystalline silicon 2o (referred to as field shielding) on the SiO2 film 21 of 800 people. ). Field shielding methods are already described in detail in the known literature. By employing self-aligned contacts and field shielding methods, the advantages of using the present invention are even more pronounced. In other words, lateral oxidation (
Leakage current due to changes in contact hole dimensions due to bird's peak) and crystal defects at the edges of the element isolation oxide film is reduced, making the self-aligned contact method easier.

メモリセル面積に関しては第5図、第6図の場合とほぼ
同じである。なお、第3図から第8図において、蓄積容
M2を構成する第2多結晶シリコン14、絶縁膜16、
第3多結果シリコン15は自己整合エツチングによりマ
スク合わせ余裕を必要とせずに加工できる。
Regarding the memory cell area, it is almost the same as in the cases of FIGS. 5 and 6. In addition, in FIGS. 3 to 8, the second polycrystalline silicon 14, the insulating film 16,
The third multi-result silicon 15 can be processed by self-aligned etching without requiring mask alignment margins.

〔発明の効果〕〔Effect of the invention〕

以−1二説明したごとく本発明によれば、蓄積容量の一
部がスイッチング・トランジスタの上部に重なるように
設けるために、従来の半導体メモリにくらべてメモリセ
ル面積を著しく小さくでき、半導体メモリの集積度を大
幅に向上できる。本発明による半導体記憶装置において
は従来の1トランジスタ型のMOSメモリのように、蓄
積容量を形成するために誘起した反転層に基づくリーク
電流が存在しないために、情報保持時間が著しく長くな
るという利点がある。
As explained above, according to the present invention, since a part of the storage capacitor is provided so as to overlap with the top of the switching transistor, the memory cell area can be significantly reduced compared to conventional semiconductor memories, and the area of the memory cell can be significantly reduced compared to conventional semiconductor memories. The degree of integration can be greatly improved. Unlike the conventional one-transistor type MOS memory, the semiconductor memory device according to the present invention has the advantage that the information retention time is significantly longer because there is no leakage current due to the inversion layer induced to form the storage capacitor. There is.

【図面の簡単な説明】[Brief explanation of the drawing]

第1図および第2図はそれぞれ本発明の一実施例を示す
平面図および断面図、第3図は従来の1トランジスタ型
MOSメモリセット1ビットの平面図、第4図はその断
面図、第5図、第7図は本発明によるMOSメモリセル
2ビツトの平面図、第6図、第8図はその断面図である
。 1ニスイツチング・トランジスタ、2:蓄積容量、3:
ワード線(AQ線)、4:データ線(拡散層)5:シリ
コン基板、6:素子間分離用酸化膜、7:ゲート酸化膜
、8:第1多結晶シリコン電極。 9:層間絶縁膜(りんガラス)、10,13:拡散層、
1に反転層、12:第1多結晶シリコン・ゲート電極、
14:第2多結晶シリコン、15:第3多結晶シリコン
、16:蓄積容量形成用絶縁膜、17.18,22:コ
ンタクト孔、19:層間酸化膜、20:フィールドシー
ルド用第1多結晶シリコン、21:フィールトシールド
用酸化膜、31:ワードM(第1多結果シリコン)、4
1:データ線(AQ線) 第7図 第2図 ¥3図 ざ 第4図 第夕図 第2図 /4f/1et) 7 /Z /3 /2710 /I
/デ第 7図 第g図 グ
1 and 2 are a plan view and a sectional view showing an embodiment of the present invention, respectively, FIG. 3 is a plan view of a conventional one-transistor type MOS memory set 1 bit, and FIG. 5 and 7 are plan views of a 2-bit MOS memory cell according to the present invention, and FIGS. 6 and 8 are sectional views thereof. 1: switching transistor, 2: storage capacitor, 3:
word line (AQ line), 4: data line (diffusion layer), 5: silicon substrate, 6: oxide film for isolation between elements, 7: gate oxide film, 8: first polycrystalline silicon electrode. 9: interlayer insulating film (phosphorus glass), 10, 13: diffusion layer,
1: inversion layer; 12: first polycrystalline silicon gate electrode;
14: second polycrystalline silicon, 15: third polycrystalline silicon, 16: insulating film for storage capacitor formation, 17, 18, 22: contact hole, 19: interlayer oxide film, 20: first polycrystalline silicon for field shield , 21: Field shield oxide film, 31: Word M (first multi-result silicon), 4
1: Data line (AQ line) Fig. 7 Fig. 2 ¥ 3 Fig. 4 Fig. 2 Fig. 2 /4f/1et) 7 /Z /3 /2710 /I
/de Figure 7 Figure g

Claims (1)

【特許請求の範囲】[Claims] 第1導電形を有する半導体基板の表面領域に所望の間隔
をもって形成された第2導電形を有する複数の不純物添
加領域と、所望の上記不純物添加領域間の上記半導体基
板上に第1の絶縁膜を介して形成された第1の導電膜か
らなるゲート電極をそなえた絶縁ゲート電界効果トラン
ジスタと、所望の上記不純物添加領域に接し、上記ゲー
ト電極を覆う第2の絶縁膜上に少なくとも延びる第2の
導電膜および該第2の導電膜上に積層して形成された第
3の絶縁膜と第3の導電膜から構成された記憶容量と、
所望の上記不純物添加領域に接し、上記第3の導電膜の
上方へ延びるデータ線を少なくともそなえ、隣接する二
つのメモリセルの上記データ線は、上記メモリセルの間
に設けられた上記不純物添加領域にコンタクト孔を介し
て接しており、かつ、上記第2の導電膜は上記第2の絶
縁膜によって定まる寸法を有する開孔部を介して上記不
純物添加領域に接していることを特徴とする半導体装置
a plurality of impurity-doped regions having a second conductivity type formed at desired intervals on a surface region of a semiconductor substrate having a first conductivity type; and a first insulating film on the semiconductor substrate between the desired impurity-doped regions. an insulated gate field effect transistor having a gate electrode made of a first conductive film formed through the insulated gate field effect transistor; a storage capacitor composed of a conductive film, a third insulating film laminated on the second conductive film, and a third conductive film;
At least a data line is provided that is in contact with the desired impurity doped region and extends above the third conductive film, and the data line of two adjacent memory cells is connected to the impurity doped region provided between the memory cells. via a contact hole, and the second conductive film is in contact with the impurity doped region via an opening having dimensions determined by the second insulating film. Device.
JP60093606A 1985-05-02 1985-05-02 Semiconductor device Granted JPS6110271A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP60093606A JPS6110271A (en) 1985-05-02 1985-05-02 Semiconductor device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP60093606A JPS6110271A (en) 1985-05-02 1985-05-02 Semiconductor device

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
JP2268577A Division JPS53108392A (en) 1976-07-05 1977-03-04 Semiconductor device

Publications (2)

Publication Number Publication Date
JPS6110271A true JPS6110271A (en) 1986-01-17
JPH0321103B2 JPH0321103B2 (en) 1991-03-20

Family

ID=14086987

Family Applications (1)

Application Number Title Priority Date Filing Date
JP60093606A Granted JPS6110271A (en) 1985-05-02 1985-05-02 Semiconductor device

Country Status (1)

Country Link
JP (1) JPS6110271A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6477158A (en) * 1987-09-18 1989-03-23 Sony Corp Memory device
JPH03263330A (en) * 1990-03-13 1991-11-22 Mitsubishi Electric Corp Semiconductor device
JPH0443674A (en) * 1990-06-11 1992-02-13 Matsushita Electron Corp Semiconductor memory device and its manufacture
US6000748A (en) * 1996-01-29 1999-12-14 Mc Micro Compact Car Aktiengesellschaft Motor vehicle having a body support structure and assembly template

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6477158A (en) * 1987-09-18 1989-03-23 Sony Corp Memory device
JPH03263330A (en) * 1990-03-13 1991-11-22 Mitsubishi Electric Corp Semiconductor device
JPH0443674A (en) * 1990-06-11 1992-02-13 Matsushita Electron Corp Semiconductor memory device and its manufacture
US6000748A (en) * 1996-01-29 1999-12-14 Mc Micro Compact Car Aktiengesellschaft Motor vehicle having a body support structure and assembly template

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JPH0321103B2 (en) 1991-03-20

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