JPH0430465A - Semiconductor device - Google Patents

Semiconductor device

Info

Publication number
JPH0430465A
JPH0430465A JP2136486A JP13648690A JPH0430465A JP H0430465 A JPH0430465 A JP H0430465A JP 2136486 A JP2136486 A JP 2136486A JP 13648690 A JP13648690 A JP 13648690A JP H0430465 A JPH0430465 A JP H0430465A
Authority
JP
Japan
Prior art keywords
contact hole
conductive layer
insulating film
layer
polycrystalline silicon
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
JP2136486A
Other languages
Japanese (ja)
Other versions
JP3049733B2 (en
Inventor
Takao Tanigawa
谷川 高穂
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.)
NEC Corp
Original Assignee
NEC Corp
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 NEC Corp filed Critical NEC Corp
Priority to JP2136486A priority Critical patent/JP3049733B2/en
Publication of JPH0430465A publication Critical patent/JPH0430465A/en
Application granted granted Critical
Publication of JP3049733B2 publication Critical patent/JP3049733B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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  • Semiconductor Memories (AREA)
  • Internal Circuitry In Semiconductor Integrated Circuit Devices (AREA)
  • Semiconductor Integrated Circuits (AREA)

Abstract

PURPOSE:To prevent a short circuit from occurring between a metal wiring and a semiconductor substrate by a method wherein an auxiliary conductive layer kept in an electrically floating state is provided under a part of the uppermost conductive layer where a contact hole is provided. CONSTITUTION:A capacitor accumulating electrode 7a of polycrystalline silicon which serves as an auxiliary conductive layer and is kept in an electrically floating state is provided surrounding an interlayer insulating film 6 and a capacitor insulating film 8 under a part of a cell plate 9 as the the uppermost conductive layer where a contact hole is formed. Even if the contact hole 12 penetrates the cell plate 9 finally due to overetching at the formation of the contact hole 12, the contact hole 12 is prevented from reaching to a silicon substrate 1, because the capacitor accumulating electrode 7a formed of a polycrystalline silicon layer 3000-4000Angstrom in thickness is provided thereunder through the intermediary of a capacitor insulating film 8 of thickness of 50-200Angstrom .

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は半導体装置に利用され、特に、半導体基板を覆
う層間絶縁膜上に形成された配線同士をコンタクトホー
ルを介して接続する構成の半導体装置に関する。
[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to semiconductor devices, and in particular, to semiconductor devices having a structure in which interconnections formed on an interlayer insulating film covering a semiconductor substrate are connected to each other via contact holes. Regarding equipment.

〔概要〕〔overview〕

本発明は、三層以上の導電層を有し、各導電層に対する
コンタクトホールが設けられた半導体装置において、 最上層の導電層のコンタクトホールが形成された下方に
、電気的に浮遊状態である例えば多結晶シリコン層から
構成された補助的導電層を設けることにより、 金属配線と半導体基板との短絡を防止したものである。
The present invention provides a semiconductor device having three or more conductive layers and contact holes for each conductive layer, in which an electrically floating state is provided below where the contact hole is formed in the uppermost conductive layer. For example, by providing an auxiliary conductive layer made of a polycrystalline silicon layer, short circuits between the metal wiring and the semiconductor substrate are prevented.

〔従来の技術〕[Conventional technology]

第4図は従来例の要部を示す縦断面図で、スタック容量
型DRAMを示す。
FIG. 4 is a vertical sectional view showing the main parts of a conventional example, showing a stacked capacitance type DRAM.

第4図において、1はシリコン基板、2はフィ−ルド酸
化膜、3はゲート酸化膜、4はゲート多結晶シリコン層
、5はMOS)ランジスタのソースまたはドレイン領域
となる不純物拡散層、6および10は層間絶縁膜、7は
容量蓄積電極、8は容量絶縁膜、9はセルプレート、1
1は金属配線、ならびに12〜15はコンタクトホール
である。
In FIG. 4, 1 is a silicon substrate, 2 is a field oxide film, 3 is a gate oxide film, 4 is a gate polycrystalline silicon layer, 5 is an impurity diffusion layer that becomes a source or drain region of a MOS transistor, 6 and 10 is an interlayer insulating film, 7 is a capacitive storage electrode, 8 is a capacitive insulating film, 9 is a cell plate, 1
1 is a metal wiring, and 12 to 15 are contact holes.

ここで、金属配線11は、不純物拡散層5と、ゲート多
結晶シリコン層4と、フィールド酸化膜2上にわたって
形成されたセルプレート9とに対して、同時に層間絶縁
膜10に開孔されたコンタクトホール12を介して接続
される。
Here, the metal wiring 11 is a contact that is simultaneously opened in the interlayer insulating film 10 to the impurity diffusion layer 5, the gate polycrystalline silicon layer 4, and the cell plate 9 formed over the field oxide film 2. It is connected via the hole 12.

〔発明が解決しようとする課題〕[Problem to be solved by the invention]

このように、複数の導電層間を同時に開孔するようなコ
ンタクトホールを形成する場合、層間絶縁膜の厚い部分
と薄い部分とが混在するために、コンタクトホールのエ
ツチング時間は層間絶縁膜の厚い部分にあわせて決定さ
れる。この場合、層間絶縁膜の膜厚差が極端に異なると
、例えば、金属配線11とセルプレート9間を接続する
コンタクトホール12を、金属配線11と不純物拡散層
5とを接続するコンタクトホール13および14ならび
に金属配線11とゲート多結晶シリコン層4とを接続す
るコンタクトホール15とを同時にあける場合、コンタ
クトホール13.14および15に比べてコンタクトホ
ール12の深さが浅いので、セルプレート9は過大な時
間エツチング雰囲気にさらされることにより、セルプレ
ート9自身がエツチングされ、最後には、コンタクトホ
ール12の部分を拡大した第5図に示すように、コンタ
クトホール12がフィールド酸化膜2を突き抜けてしま
い、後に金属配線11を形成した場合、金属配線11と
シリコン基板1とが電気的に短絡してしまう欠点があっ
た。
In this way, when forming a contact hole that simultaneously opens between multiple conductive layers, the etching time for the contact hole is longer than the etching time for the thicker part of the interlayer insulating film because the thicker and thinner parts of the interlayer insulating film coexist. It will be decided according to the In this case, if the interlayer insulating film has an extremely different thickness, for example, the contact hole 12 connecting the metal wiring 11 and the cell plate 9 may be replaced with the contact hole 13 connecting the metal wiring 11 and the impurity diffusion layer 5. 14 and the contact hole 15 connecting the metal wiring 11 and the gate polycrystalline silicon layer 4, the contact hole 12 is shallower than the contact holes 13, 14 and 15, so the cell plate 9 is too large. By being exposed to the etching atmosphere for a long time, the cell plate 9 itself is etched, and eventually the contact hole 12 penetrates through the field oxide film 2, as shown in FIG. 5, which is an enlarged view of the contact hole 12. However, when the metal wiring 11 is formed later, there is a drawback that the metal wiring 11 and the silicon substrate 1 are electrically short-circuited.

本発明の目的は、前記の欠点を除去することにより、複
数の導電層間に同時にコンタクトホールを形成しても、
金属配線と半導体基板とが短絡することのない半導体装
置を提供することにある。
An object of the present invention is to eliminate the above-mentioned drawbacks, thereby making it possible to form contact holes between multiple conductive layers at the same time.
An object of the present invention is to provide a semiconductor device in which a metal wiring and a semiconductor substrate are not short-circuited.

〔課題を解決するための手段〕[Means to solve the problem]

本発明は、半導体基板の一主面に形成された三層以上の
導電層と、前記三層以上の導電層を覆うて形成された層
間絶縁膜と、前記層絶縁膜を貫通してそれぞれ前記導電
層に到達して形成された少なくとも3個のコンタクトホ
ールとを備えた半導体装置において、前記導電層のうち
最上層の導電層のコンタクトホールが形成された下方に
設けられ、電気的に浮遊状態に保持された補助的導電層
を備えたことを特徴とする。
The present invention provides three or more conductive layers formed on one principal surface of a semiconductor substrate, an interlayer insulating film formed to cover the three or more conductive layers, and an interlayer insulating film that penetrates through the layer insulating film. In a semiconductor device having at least three contact holes formed by reaching a conductive layer, the conductive layer is provided below the contact hole in the uppermost conductive layer of the conductive layer, and is in an electrically floating state. characterized by comprising an auxiliary conductive layer held in place.

また、本発明は、前記補助的導電層は多結晶シリコン層
から構成とすることができる。
Further, in the present invention, the auxiliary conductive layer may be composed of a polycrystalline silicon layer.

〔作用〕[Effect]

最上層の導電層の下郎には、例えば多結晶シリコン層か
ら構成され、電気的に浮遊(フローティング)状態に保
持された補助的導電層が設けられているので、コンタク
トホール形成時に、例え当該導電層がエツチングにより
なくなったにしても、補助的導電層に遮られて半導体基
板に達することはない。
An auxiliary conductive layer made of, for example, a polycrystalline silicon layer and held in an electrically floating state is provided below the uppermost conductive layer. Even if the layer is etched away, it is not blocked by the auxiliary conductive layer and does not reach the semiconductor substrate.

従って、金属配線と半導体基板との短絡を防止すること
が可能となる。しかも、補助的導電層は電気的に浮遊状
態に保持されているので、装置の特性に影響を及ぼすこ
ともない。
Therefore, it is possible to prevent short circuits between the metal wiring and the semiconductor substrate. Moreover, since the auxiliary conductive layer is held in an electrically floating state, it does not affect the characteristics of the device.

〔実施例〕〔Example〕

以下、本発明の実施例について図面を参照して説明する
Embodiments of the present invention will be described below with reference to the drawings.

第1図は本発明の第一実施例の要部を示す縦断面図で、
スタック容量型DRAMを示す。また、第2図(a)お
よび(b)は第1図のコンタクトホール12部分の詳細
を示す平面図およびそのA−A’断面図である。
FIG. 1 is a longitudinal sectional view showing the main parts of the first embodiment of the present invention.
A stacked capacity DRAM is shown. 2(a) and 2(b) are a plan view showing details of the contact hole 12 portion of FIG. 1 and a cross-sectional view thereof taken along the line AA'.

本第−実施例は、半導体基板としてのシリコン基板1の
一主面上に形成された、三層の導電層としての、不純物
拡散層5、ゲート多結晶シリコン層4およびセルプレー
ト9と、これらを覆うて形成された層間絶縁膜6および
10と、この層間絶縁膜6および10または10を貫通
して、不純物拡散層5およびゲート多結晶シリコン層4
、またはセルプレート9に到達して形成されたコンタク
トホール13.14および15、ならびに12とを備え
た半導体装置において、 本発明の特徴とするところの、 最上層の導電層であるところのセルプレート9のコンタ
クトホール12が形成された下方に、層間絶縁膜6と容
量絶縁膜8とで囲んで、電気的に浮遊状態に保持した補
助導電層としての多結晶シリコンからなる容量蓄積電極
7aを備えている。
The present embodiment includes an impurity diffusion layer 5, a gate polycrystalline silicon layer 4, and a cell plate 9 as three conductive layers formed on one main surface of a silicon substrate 1 as a semiconductor substrate. The impurity diffusion layer 5 and the gate polycrystalline silicon layer 4 are formed by penetrating the interlayer insulating films 6 and 10 or 10.
, or contact holes 13, 14 and 15, and 12 formed by reaching the cell plate 9. A feature of the present invention is that the cell plate is the uppermost conductive layer. A capacitor storage electrode 7a made of polycrystalline silicon as an auxiliary conductive layer is surrounded by an interlayer insulating film 6 and a capacitor insulating film 8 and held in an electrically floating state below the contact hole 12 of No. 9. ing.

なお、第1図において、2はフィールド酸化膜、3はゲ
ート酸化膜、7は多結晶シリコンからなる容量蓄積電極
、および11は金属配線である。
In FIG. 1, 2 is a field oxide film, 3 is a gate oxide film, 7 is a capacitor storage electrode made of polycrystalline silicon, and 11 is a metal wiring.

本第二実施例によれば、第2図(a)および(b)に示
すように、例えば150OAの多結晶シリコン層で形成
されたセルプレート9が、コンタクトホール12を形成
する際の過大なエツチングによりエツチングされ、最終
的にコンタクトホール12がセルプレート9を突き抜け
ても、下層に例えば50〜200人の容量絶縁膜8を介
して3000〜4000 Aの多結晶シリコン層で形成
された容量蓄積電極7aがあるので、コンタクトホール
12がシリコン基板1まで達することを防ぐことができ
る。
According to the second embodiment, as shown in FIGS. 2(a) and 2(b), the cell plate 9 formed of, for example, a 150 OA polycrystalline silicon layer is Even if the contact hole 12 is etched and finally penetrates through the cell plate 9, the capacitance storage is formed by a polycrystalline silicon layer of 3000 to 4000 A with a capacitance insulating film 8 of 50 to 200 amps in the lower layer. The presence of the electrode 7a can prevent the contact hole 12 from reaching the silicon substrate 1.

第3図(a)およびら)は本発明第二実施例のコンタク
トホール部分の詳細を示す平面図およびそのBB′断面
図である。
FIGS. 3(a) and 3(a) are a plan view showing details of a contact hole portion of a second embodiment of the present invention and a sectional view taken along line BB' thereof.

本第二実施例は、第一実施例と同様に、本発明の特徴と
するところの、金属配線11とセルプレート9とを接続
するコンタクトホール12を開孔する領域のセルプレー
ト9とを接続するコンタクトホール12を開孔する領域
のセルプレート9の下方に、フィールド酸化膜2と層間
絶縁膜6とで囲んで、電気的に浮遊状態のゲート多結晶
シリコン層4aを設けたものである。
The second embodiment, like the first embodiment, connects the cell plate 9 in the region where the contact hole 12 connecting the metal wiring 11 and the cell plate 9 is formed, which is a feature of the present invention. An electrically floating gate polycrystalline silicon layer 4a is provided below the cell plate 9 in the area where the contact hole 12 is to be formed, surrounded by the field oxide film 2 and the interlayer insulating film 6.

本第二実施例では、セルプレート9とゲート多結晶シリ
コン層4aとの間に、層間絶縁膜6として例えば200
0〜5000 Aのシリコン酸化膜あるいはBPSG膜
を有し、さらに、例えば3000〜4000 Aのゲー
ト多結晶シリコン層4aを有するために、コンタクト形
成時の過大なエツチングにより金属配線11とシリコン
基板1が電気的に短絡することを防止できる。
In the second embodiment, the interlayer insulating film 6 is formed between the cell plate 9 and the gate polycrystalline silicon layer 4a.
Since it has a silicon oxide film or a BPSG film with a thickness of 0 to 5000 A, and further has a gate polycrystalline silicon layer 4a with a thickness of, for example, 3000 to 4000 A, the metal wiring 11 and the silicon substrate 1 may be damaged due to excessive etching during contact formation. Electrical short circuits can be prevented.

また、本第二実施例では、セルプレート9とゲート多結
晶シリコン層4aの間に2000〜5000 Aのシリ
コン酸化膜あるいはBPSG膜からなる層間絶縁膜6を
有するので、第一実施例に比べてさらに長い時間の過大
なエツチングに耐えることができる。
In addition, in the second embodiment, since the interlayer insulating film 6 made of a silicon oxide film or BPSG film of 2000 to 5000 A is provided between the cell plate 9 and the gate polycrystalline silicon layer 4a, compared to the first embodiment, Furthermore, it can withstand excessive etching for a long time.

〔発明の効果〕〔Effect of the invention〕

以上説明したように、本発明は、コンタクトホールを開
孔する部分の最上層の導電層直下に、補助導電層として
、電気的に浮遊状態の例えば多結晶シリコン層を設ける
ことにより、コンタクトホール形成時の過大なエツチン
グにより金属配線とシリコン基板とが電気的に短絡する
ことを防止できる効果がある。
As explained above, the present invention enables contact hole formation by providing an electrically floating state, for example, a polycrystalline silicon layer, as an auxiliary conductive layer directly under the uppermost conductive layer in the area where the contact hole is to be opened. This has the effect of preventing electrical short-circuits between the metal wiring and the silicon substrate due to excessive etching at the time of etching.

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

第1図は本発明の第一実施例の要部を示す縦断面図。 第2図(a)はそのコンタクトホール部分の詳細を示す
平面図。 第2図ら)は第2図(a)のA−A’断面図。 第3図(a)は本発明第二実施例のコンタクトホール部
分の詳細を示す平面図。 第3図ら)は第3図(a)のB−B’断面図。 第4図は従来例の要部を示す縦断面図。 第5図(a)はそのコンタクトホール部分の詳細を示す
平面図。 第5図ら)は第5図(a)のc−c’断面図。 1・・・シリコン基板、2・・・フィールド酸化膜、3
・・・ゲート酸化膜、4.4a・・・ゲート多結晶シリ
コン層、5・・・不純物拡散層、6.10・・・層間絶
縁膜、7.7a・・・容量蓄積電極、8−・・容量絶縁
膜、9・・セルプレート、11・・・金属配線、12〜
15・・・コンタクトホール。
FIG. 1 is a longitudinal sectional view showing the main parts of a first embodiment of the present invention. FIG. 2(a) is a plan view showing details of the contact hole portion. FIG. 2(a) is a sectional view taken along the line AA' in FIG. 2(a). FIG. 3(a) is a plan view showing details of the contact hole portion of the second embodiment of the present invention. FIG. 3(a) is a sectional view taken along line BB' in FIG. 3(a). FIG. 4 is a longitudinal sectional view showing the main parts of a conventional example. FIG. 5(a) is a plan view showing details of the contact hole portion. FIG. 5(a) is a sectional view taken along line cc' in FIG. 5(a). 1... Silicon substrate, 2... Field oxide film, 3
...Gate oxide film, 4.4a...Gate polycrystalline silicon layer, 5...Impurity diffusion layer, 6.10...Interlayer insulating film, 7.7a...Capacitance storage electrode, 8-...・Capacitive insulating film, 9...Cell plate, 11...Metal wiring, 12~
15...Contact hole.

Claims (1)

【特許請求の範囲】 1、半導体基板の一主面に形成された三層以上の導電層
と、 前記三層以上の導電層を覆うて形成された層間絶縁膜と
、 前記層絶縁膜を貫通してそれぞれ前記導電層に到達して
形成された少なくとも3個のコンタクトホールと を備えた半導体装置において、 前記導電層のうち最上層の導電層のコンタクトホールが
形成された下方に設けられ、電気的に浮遊状態に保持さ
れた補助的導電層 を備えたことを特徴とする半導体装置。 2、前記補助的導電層は多結晶シリコン層から構成され
た請求項1記載の半導体装置。
[Claims] 1. Three or more conductive layers formed on one principal surface of a semiconductor substrate, an interlayer insulating film formed to cover the three or more conductive layers, and an interlayer insulating film that penetrates the layer insulating film. and at least three contact holes formed in the uppermost conductive layer among the conductive layers, each contact hole being formed below the contact hole in the uppermost conductive layer and reaching the conductive layer. 1. A semiconductor device comprising an auxiliary conductive layer held in a floating state. 2. The semiconductor device according to claim 1, wherein said auxiliary conductive layer is comprised of a polycrystalline silicon layer.
JP2136486A 1990-05-25 1990-05-25 Semiconductor device Expired - Fee Related JP3049733B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2136486A JP3049733B2 (en) 1990-05-25 1990-05-25 Semiconductor device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2136486A JP3049733B2 (en) 1990-05-25 1990-05-25 Semiconductor device

Publications (2)

Publication Number Publication Date
JPH0430465A true JPH0430465A (en) 1992-02-03
JP3049733B2 JP3049733B2 (en) 2000-06-05

Family

ID=15176270

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2136486A Expired - Fee Related JP3049733B2 (en) 1990-05-25 1990-05-25 Semiconductor device

Country Status (1)

Country Link
JP (1) JP3049733B2 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002237525A (en) * 1995-01-31 2002-08-23 Fujitsu Ltd Semiconductor memory device and manufacturing method therefor
JP2005252279A (en) * 2005-03-30 2005-09-15 Fujitsu Ltd Semiconductor device and its manufacturing method
JP2008263211A (en) * 1995-01-31 2008-10-30 Fujitsu Ltd Semiconductor device
US7649261B2 (en) 1996-07-18 2010-01-19 Fujitsu Microelectronics Limited Highly integrated and reliable DRAM and its manufacture
JP2010050474A (en) * 2009-10-20 2010-03-04 Fujitsu Microelectronics Ltd Semiconductor device, and method of manufacturing the same
US8404554B2 (en) 1995-01-31 2013-03-26 Fujitsu Semiconductor Limited Method of manufacturing semiconductor device

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013202097A (en) * 2012-03-27 2013-10-07 Barcos Co Ltd Bag

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002237525A (en) * 1995-01-31 2002-08-23 Fujitsu Ltd Semiconductor memory device and manufacturing method therefor
JP2008263211A (en) * 1995-01-31 2008-10-30 Fujitsu Ltd Semiconductor device
US8404554B2 (en) 1995-01-31 2013-03-26 Fujitsu Semiconductor Limited Method of manufacturing semiconductor device
US8674421B2 (en) 1995-01-31 2014-03-18 Fujitsu Semiconductor Limited Semiconductor device
US7649261B2 (en) 1996-07-18 2010-01-19 Fujitsu Microelectronics Limited Highly integrated and reliable DRAM and its manufacture
US8143723B2 (en) 1996-07-18 2012-03-27 Fujitsu Semiconductor Limited Highly integrated and reliable DRAM and its manufacture
JP2005252279A (en) * 2005-03-30 2005-09-15 Fujitsu Ltd Semiconductor device and its manufacturing method
JP2010050474A (en) * 2009-10-20 2010-03-04 Fujitsu Microelectronics Ltd Semiconductor device, and method of manufacturing the same

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