JP3489602B2 - Semiconductor device and manufacturing method thereof - Google Patents
Semiconductor device and manufacturing method thereofInfo
- Publication number
- JP3489602B2 JP3489602B2 JP19326995A JP19326995A JP3489602B2 JP 3489602 B2 JP3489602 B2 JP 3489602B2 JP 19326995 A JP19326995 A JP 19326995A JP 19326995 A JP19326995 A JP 19326995A JP 3489602 B2 JP3489602 B2 JP 3489602B2
- Authority
- JP
- Japan
- Prior art keywords
- region
- conductivity type
- insulating film
- type
- type region
- 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 - Fee Related
Links
- 239000004065 semiconductor Substances 0.000 title claims description 33
- 238000004519 manufacturing process Methods 0.000 title claims description 12
- 238000000034 method Methods 0.000 claims description 29
- 230000002457 bidirectional effect Effects 0.000 claims description 25
- 229910021420 polycrystalline silicon Inorganic materials 0.000 claims description 23
- 229920005591 polysilicon Polymers 0.000 claims description 23
- 239000000758 substrate Substances 0.000 claims description 13
- 230000015556 catabolic process Effects 0.000 claims description 10
- 238000005530 etching Methods 0.000 claims description 9
- 230000005669 field effect Effects 0.000 claims description 6
- 239000010410 layer Substances 0.000 description 10
- 238000000206 photolithography Methods 0.000 description 10
- 239000011229 interlayer Substances 0.000 description 6
- 150000002500 ions Chemical class 0.000 description 6
- 229910052796 boron Inorganic materials 0.000 description 5
- 230000003647 oxidation Effects 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 4
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 3
- 238000005468 ion implantation Methods 0.000 description 3
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- 229910052785 arsenic Inorganic materials 0.000 description 2
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 2
- -1 boron ions Chemical class 0.000 description 2
- 239000007943 implant Substances 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 239000011574 phosphorus Substances 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000007738 vacuum evaporation Methods 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
- H01L29/76—Unipolar devices, e.g. field effect transistors
- H01L29/772—Field effect transistors
- H01L29/78—Field effect transistors with field effect produced by an insulated gate
- H01L29/7801—DMOS transistors, i.e. MISFETs with a channel accommodating body or base region adjoining a drain drift region
- H01L29/7802—Vertical DMOS transistors, i.e. VDMOS transistors
- H01L29/7803—Vertical DMOS transistors, i.e. VDMOS transistors structurally associated with at least one other device
- H01L29/7808—Vertical DMOS transistors, i.e. VDMOS transistors structurally associated with at least one other device the other device being a breakdown diode, e.g. Zener diode
Landscapes
- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Ceramic Engineering (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- Semiconductor Integrated Circuits (AREA)
- Metal-Oxide And Bipolar Metal-Oxide Semiconductor Integrated Circuits (AREA)
- Insulated Gate Type Field-Effect Transistor (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、半導体装置および
その製造方法に関し、特にＭＯＳＦＥＴ型電界効果トラ
ンジスタ（以下ＭＯＳＦＥＴと記す）のゲート・ソース
間に双方向性ダイオードを接続した半導体装置およびそ
の製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and a method for manufacturing the same, and more particularly to a semiconductor device in which a bidirectional diode is connected between the gate and source of a MOSFET field effect transistor (hereinafter referred to as MOSFET) and a method for manufacturing the same. Regarding
【０００２】[0002]
【従来の技術】図３に示す従来の半導体装置のＭＯＳＦ
ＥＴ１は、ゲート絶縁膜厚が約５００Åと薄く、このゲ
ート絶縁膜の静電破壊防止用にＭＯＳＦＥＴ１のゲート
（Ｇ）・ソース（Ｓ）間に双方向性ダイオード２を接続
している。2. Description of the Related Art MOSF of a conventional semiconductor device shown in FIG.
The ET1 has a thin gate insulating film thickness of about 500Å, and the bidirectional diode 2 is connected between the gate (G) and the source (S) of the MOSFET 1 to prevent electrostatic breakdown of the gate insulating film.
【０００３】このＭＯＳＦＥＴ１の製造工程を以下に説
明する。
（１−１）Ｎ+ 型半導体基板３上にＮ型エピタキシャル
層を成長させてドレイン領域４を形成した後、このドレ
イン領域４の表面に熱酸化法によりフィールド絶縁膜５
を形成し、このフイールド絶縁膜５をフォトグラフィ法
及びエッチング法により選択的に除去した後、ドレイン
領域４の露呈された表面に熱酸化法によりゲート絶縁膜
６を形成する。
（１−２）このゲート絶縁膜６の上面にゲート電極７を
構成するポリシリコン膜を被覆した後、このポリシリコ
ン膜をフォトグラフィ法及びエッチング法により選択的
に除去してゲート絶縁膜６上にゲート電極７を残す。こ
のゲート電極７はリンをイオン注入して低抵抗化してお
く。
（１−３）ゲート電極７をマスクとして、ゲート絶縁膜
６をエッチングして、開口されたドレイン領域４上の窓
にイオン注入してＰ型ベース領域８を形成する。
（１−４）フォトグラフィ法によりレジスト膜をマスク
として、ベース領域８の上面ほぼ中央部に開口された窓
にイオン注入してＰ+ 型ベースコンタクト領域９を形成
する。
（１−５）ベースコンタクト領域９上を被覆したレジス
ト膜とゲート電極７ををマスクとして、開口された窓に
イオン注入してＮ+ 型ソース領域１０を形成する。
（１−６）以上の工程を終了した半導体基板３上に、Ｃ
ＶＤ法により層間絶縁膜１１を堆積した後、フォトグラ
フィ法及びエッチング法によりソース領域１０及びベー
スコンタクト領域９上とゲート電極７上との層間絶縁膜
１１にコンタクト窓を開口してソース配線１２とゲート
配線１３を真空蒸着により形成するとともに、基板３の
裏面にドレイン電極１４を形成し、ＭＯＳＦＥＴ１が完
成する。The manufacturing process of the MOSFET 1 will be described below. (1-1) After the N type epitaxial layer is grown on the N + type semiconductor substrate 3 to form the drain region 4, the field insulating film 5 is formed on the surface of the drain region 4 by the thermal oxidation method.
Then, the field insulating film 5 is selectively removed by the photolithography method and the etching method, and then the gate insulating film 6 is formed on the exposed surface of the drain region 4 by the thermal oxidation method. (1-2) After covering the upper surface of the gate insulating film 6 with the polysilicon film forming the gate electrode 7, the polysilicon film is selectively removed by a photolithography method and an etching method to form the gate insulating film 6 on the gate insulating film 6. The gate electrode 7 is left. The gate electrode 7 is made to have a low resistance by ion-implanting phosphorus. (1-3) The gate insulating film 6 is etched using the gate electrode 7 as a mask, and ions are implanted into the opened window on the drain region 4 to form a P-type base region 8. (1-4) Using the resist film as a mask by the photolithography method, ions are implanted into a window opened in the central portion of the upper surface of the base region 8 to form the P + -type base contact region 9. (1-5) Using the resist film covering the base contact region 9 and the gate electrode 7 as a mask, ions are implanted into the opened window to form the N + type source region 10. (1-6) C is placed on the semiconductor substrate 3 after the above steps.
After depositing the interlayer insulating film 11 by the VD method, a contact window is opened in the interlayer insulating film 11 on the source region 10 and the base contact region 9 and on the gate electrode 7 by the photography method and the etching method to form the source wiring 12. The gate wiring 13 is formed by vacuum vapor deposition, and the drain electrode 14 is formed on the back surface of the substrate 3 to complete the MOSFET 1.
【０００４】次いで、双方向性ダイオード２の製造工程
を以下に説明する。
（２−１）上記（１−２）項でポリシリコン膜を形成す
るとき、フィールド絶縁膜５の上面にも同時にポリシリ
コン膜を被覆した後、ポリシリコン膜を選択的に除去す
るとき同時に、フィールド絶縁膜５の上面にポリシリコ
ンブロックを残す。
（２−２）上記（１−３）項でＰ型ベース領域８を形成
するとき同時に、ポリシリコンブロックにもイオン注入
してＰ型領域１５を形成する。
（２−３）上記（１−５）項でソース領域１０を形成す
るとき同時に、Ｐ型領域１５の上面中央部を被覆したレ
ジスト膜をマスクとして、Ｐ型領域１５の開口された両
端部の窓にイオン注入してＮ+ 型領域１６を形成する。
（２−４）上記（１−６）項でソース配線１２及びゲー
ト配線１３を形成するとき同時に、Ｎ+ 型領域１６上の
層間絶縁膜１１にコンタクト窓を開口して、ソース配線
１２をＮ+ 型領域１６の一方に電気的に接続し、ゲート
配線１３をＮ+型領域１６の他方に電気的に接続し、Ｍ
ＯＳＦＥＴ１に接続された双方向性ダイオード２が完成
する。Next, the manufacturing process of the bidirectional diode 2 will be described below. (2-1) When the polysilicon film is formed in the above (1-2), the upper surface of the field insulating film 5 is simultaneously covered with the polysilicon film, and then the polysilicon film is selectively removed. A polysilicon block is left on the upper surface of the field insulating film 5. (2-2) At the same time when the P-type base region 8 is formed in (1-3) above, ions are also implanted into the polysilicon block to form the P-type region 15. (2-3) Simultaneously with the formation of the source region 10 in the above item (1-5), the resist film covering the central portion of the upper surface of the P-type region 15 is used as a mask to expose the both ends of the P-type region 15 which are opened. Ions are implanted into the window to form the N + type region 16. (2-4) At the same time when the source wiring 12 and the gate wiring 13 are formed in the above item (1-6), a contact window is opened in the interlayer insulating film 11 on the N + type region 16 so that the source wiring 12 is N-shaped. Electrically connected to one of the + type regions 16 and electrically connecting the gate wiring 13 to the other of the N + type regions 16;
The bidirectional diode 2 connected to the OSFET 1 is completed.
【０００５】[0005]
【発明が解決しようとする課題】上記構成の半導体装置
では、ＭＯＳＦＥＴ１のＰ型ベース領域８及びＮ+ 型ソ
ース領域１０を形成するときのイオン注入で双方向性ダ
イオード２のＰ型領域１５及びＮ+ 型領域１６を形成し
ている。そのため、イオン注入の条件は、ＭＯＳＦＥＴ
１の特性を決めるためのものであり、その結果、双方向
性ダイオード２のツェナー耐圧は一義的に決定されるた
め、工程数を増やさずに任意のツェナー耐圧に制御する
ことはできないという問題があった。また双方向性ダイ
オード２は、単結晶ではなくポリシリコン膜で形成され
ているためツェナー波形が垂直に立ち上がった波形（以
下ハード波形と記す）ではなく傾斜した波形（以下ソフ
ト波形と記す）になりやすい。またＰ型領域１５は低濃
度の不純物層で形成されているためツェナー波形が抵抗
成分によりソフト波形となる。しかもＰ型領域１５上は
絶縁膜で被覆されており、低濃度のＰ型層の表面は一部
反転し、Ｐ型領域１５とＮ+ 型領域１６との接合部の空
乏層の広がりは大きくなる。したがって、縦方向に形成
された接合部の表面部と内部で空乏層幅が異なり、ツェ
ナー波形がソフト波形となる。このために、蓄積された
静電気により流れるツェナー電流値が異なるとき、ツェ
ナー耐圧値も異なるため、ゲート定格に対して大きなマ
ージンでツェナー耐圧規格を設計しなければならず、Ｅ
ＳＤ耐量を高くすることが難しかった。従って、本発明
はこのような事情に鑑みなされたもので、従来と同一工
程数で双方向性ダイオードのツェナー耐圧を容易に制御
でき、且つ、ツェナー波形もハード波形に近付けること
ができる半導体装置を提供することを目的とする。In the semiconductor device having the above structure, ion implantation is performed when forming the P type base region 8 and the N + type source region 10 of the MOSFET 1, and the P type region 15 and the N type region of the bidirectional diode 2 are formed. A + type region 16 is formed. Therefore, the condition of ion implantation is MOSFET
The zener breakdown voltage of the bidirectional diode 2 is uniquely determined as a result, so that it is impossible to control the zener breakdown voltage to an arbitrary zener breakdown voltage without increasing the number of steps. there were. In addition, since the bidirectional diode 2 is formed of a polysilicon film rather than a single crystal, the zener waveform has an inclined waveform (hereinafter referred to as a soft waveform) rather than a vertically rising waveform (hereinafter referred to as a hard waveform). Cheap. Further, since the P-type region 15 is formed of the low concentration impurity layer, the Zener waveform becomes a soft waveform due to the resistance component. Moreover, the P-type region 15 is covered with the insulating film, the surface of the low-concentration P-type layer is partially inverted, and the spread of the depletion layer at the junction between the P-type region 15 and the N + -type region 16 is large. Become. Therefore, the depletion layer width is different between the surface portion and the inside of the junction formed in the vertical direction, and the Zener waveform becomes a soft waveform. For this reason, when the Zener current value flowing due to the accumulated static electricity is different, the Zener withstand voltage value is also different. Therefore, the Zener withstand voltage standard must be designed with a large margin with respect to the gate rating.
It was difficult to increase the SD tolerance. Therefore, the present invention has been made in view of the above circumstances, and a semiconductor device in which the Zener withstand voltage of a bidirectional diode can be easily controlled in the same number of steps as in the related art and the Zener waveform can be close to a hard waveform. The purpose is to provide.
【０００６】[0006]
【課題を解決するための手段】本発明は、上記課題を解
決するために提案されたもので、半導体基板に形成した
電界効果型トランジスタのゲート・ソース間に、半導体
基板上の絶縁膜中に形成した一導電型領域と他導電型領
域とを含む双方向性ダイオードを接続した半導体装置に
おいて、ダイオードの他導電型領域の中央部に高濃度領
域を形成したことを特徴とする半導体装置を提供する。
また、高濃度一導電型半導体基板上に一導電型ドレイン
領域を形成し、この領域上にフィールド絶縁膜とゲート
絶縁膜とを形成する工程と、フィールド絶縁膜及びゲー
ト絶縁膜上にポリシリコン膜を被覆し、このポリシリコ
ン膜を選択的にエッチングして、フィールド絶縁膜上に
ポリシリコンブロックとゲート絶縁膜上にゲート電極と
を同時に形成する工程と、ブロックに他導電型領域とド
レイン領域に他導電型ベース領域とを同時に形成する工
程と、ブロックの他導電型領域の中央部に高濃度他導電
型領域とベース領域の中央部に高濃度他導電型ベースコ
ンタクト領域とを選択的に同時に形成する工程と、ブロ
ックの他導電型領域の両端部に高濃度一導電型領域とベ
ース領域に高濃度一導電型ソース領域とを同時に形成す
る工程とを含む電界効果型トランジスタのゲート・ソー
ス間にブロックに形成された双方向性ダイオードを接続
した半導体装置の製造方法を提供する。また、上記の半
導体装置の製造方法において、ブロックの高濃度他導電
型領域の長さ寸法によりダイオードのツェナー耐圧を制
御することを特徴とする。The present invention has been proposed in order to solve the above-mentioned problems, and is provided between the gate and the source of a field effect transistor formed on a semiconductor substrate and in an insulating film on the semiconductor substrate. Provided is a semiconductor device in which a bidirectional diode including a formed region of one conductivity type and a region of another conductivity type is connected, wherein a high-concentration region is formed in a central portion of the other conductivity type region of the diode. To do.
Further, a step of forming a one-conductivity type drain region on a high-concentration one-conductivity type semiconductor substrate and forming a field insulating film and a gate insulating film on this region, and a polysilicon film on the field insulating film and the gate insulating film. And selectively etching this polysilicon film to form a polysilicon block on the field insulating film and a gate electrode on the gate insulating film at the same time, and another conductive type region and drain region in the block. The step of simultaneously forming the other conductivity type base region and the high concentration other conductivity type region in the center of the other conductivity type region of the block and the high concentration other conductivity type base contact region in the center of the base region are selectively and simultaneously performed. And a step of simultaneously forming a high-concentration one-conductivity type region at both ends of the other conductivity type region of the block and a high-concentration one-conductivity type source region in the base region. To provide a method of manufacturing a semiconductor device connected bidirectional diode formed in the block between the gate and source of the effect transistor. Further, in the above-described method for manufacturing a semiconductor device, the Zener breakdown voltage of the diode is controlled by the length dimension of the high-concentration other conductivity type region of the block.
【０００７】[0007]
【作用】上記の手段によれば、ＭＯＳＦＥＴのＰ+ ベー
スコンタクト領域形成時に、レジストをマスクとして、
双方向性ダイオードのＰ型領域の中央部に開口された窓
にも同時にイオン注入してＰ+ 型領域を形成するので、
従来からの工程数でマスクの開口窓寸法を変えることに
よりＰ+ 型領域の寸法を制御でき、その結果、ツェナー
耐圧を容易に制御できる。また、双方向性ダイオードの
Ｐ型領域の中央部にＰ+ 型領域を形成するので、Ｐ型領
域の抵抗がＰ+ 領域により低抵抗化してツェナー波形の
抵抗成分が減少すると共に、Ｐ型領域とＮ+ 型領域との
接合部で生じる空乏層の伸びがＰ+ 型領域で止まるため
縦方向に形成した接合部の表面部と内部とで空乏層幅が
変わらず、ツェナー波形をハード波形に近付けることが
できる。According to the above means, the resist is used as a mask when forming the P + base contact region of the MOSFET.
Since ions are simultaneously implanted into the window opened at the center of the P-type region of the bidirectional diode to form the P + -type region,
The size of the P + type region can be controlled by changing the size of the opening window of the mask by the conventional number of steps, and as a result, the Zener breakdown voltage can be easily controlled. Further, since the P + -type region is formed in the center of the P-type region of the bidirectional diode, the resistance of the P-type region is lowered by the P + region, the resistance component of the Zener waveform is reduced, and the P-type region is reduced. Since the extension of the depletion layer that occurs at the junction between the N + type region and the N + type region stops at the P + type region, the depletion layer width does not change between the surface and the inside of the vertically formed junction, and the Zener waveform becomes a hard waveform. You can get closer.
【０００８】[0008]
【実施例】以下に、本発明の実施例を図１及び図２を参
照して説明する。尚、図１及び図２において、図３と同
一のものは同一符号を以て示し、図１の構成については
重複した説明を省略する。先ず構成を説明すると、図１
において図３と異なる点は双方向性ダイオード２２の構
成においてＰ型領域２５の中央部にＰ+ 型領域２５ａを
形成していることである。Embodiments of the present invention will be described below with reference to FIGS. 1 and 2, the same elements as those in FIG. 3 are designated by the same reference numerals, and the duplicated description of the configuration in FIG. 1 will be omitted. First, the structure will be described with reference to FIG.
3 is different from FIG. 3 in that in the structure of the bidirectional diode 22, the P + type region 25a is formed in the central portion of the P type region 25.
【０００９】次いで半導体装置の製造工程の一例を図２
の（Ａ）〜（Ｆ）を用いて説明する。尚、以下の説明に
おいて（Ａ）〜（Ｂ）の各項目記号は、図２の（Ａ）〜
（Ｆ）のそれぞれに対応する。
（Ａ）Ｎ+ 型半導体基板３上にＮ型エピタキシャル層を
成長させてドレイン領域４を形成した後、このドレイン
領域４の表面に熱酸化法によりフィールド絶縁膜５を形
成し、このフィールド絶縁膜５をフォトグラフィ法及び
エッチング法により選択的に除去した後、ドレイン領域
４の露呈された表面に熱酸化法によりゲート絶縁膜６を
形成する。
（Ｂ）これらの絶縁膜５，６の上面に破線で示すポリシ
リコン膜２３を被覆した後、このポリシリコン膜２３を
フォトグラフィ法及びエッチング法により選択的に除去
してフィールド絶縁膜５上にポリシリコンブロック２４
とゲート絶縁膜６上にゲート電極７を残す。このゲート
電極７は、フォトグラフィ法によりレジスト膜をマスク
として、リンをイオン注入して低抵抗化しておく。
（Ｃ）ゲート電極７をマスクとして、ゲート絶縁膜６を
エッチングして開口された窓にボロンをイオン注入して
Ｐ型ベース領域８を形成すると同時に、ポリシリコンブ
ロック２４上全面にもボロンをイオン注入してＰ型領域
２５を形成する。
（Ｄ）フォトグラフィ法によりレジスト膜をマスクとし
て、ベース領域８の上面中央部に開口された窓に高濃度
のボロンをイオン注入してＰ+ 型ベースコンタクト領域
９を形成すると同時に、Ｐ型領域２５の上面中央部に開
口された窓にも高濃度のボロンをイオン注入してＰ+ 型
領域２５ａを形成する。尚、Ｐ型領域２５の上面中央部
の窓の開口寸法（ブロック２４の長さ方向）を制御し
て、所定のツェナー耐圧を得る。
（Ｅ）フォトグラフィ法により選択的にベースコンタク
ト領域９の上面を被覆したレジスト膜とゲート電極７を
マスクとして、開口された窓に砒素をイオン注入してＮ
+ ソース領域１０を形成すると同時に、フォトグラフィ
法によりＰ型領域２５の上面を被覆したレジスト膜をマ
スクとして、Ｐ型領域２５両端部の開口された窓にも砒
素をイオン注入してＮ+ 型領域１６を形成する。。
（Ｆ）以上の工程を終了した半導体基板３の上面にＣＶ
Ｄ法により層間絶縁膜１１を堆積し、フォトグラフィ法
及びエッチング法によりＭＯＳＦＥＴ１のソース領域１
０，ベースコンタクト領域９及びゲート電極７上と双方
向性ダイオード２２のＮ+ 型領域１６上との層間絶縁膜
１１にコンタクト窓を開口した後、その半導体基板３の
上面に真空蒸着によりアルミニウム膜を被覆し、このア
ルミニウム膜をフォトグラフィ法及びエッチング法によ
り選択的に除去して、ソース領域１０及びベースコンタ
クト領域９と電気的に接続するソース配線１２と、ゲー
ト電極７と電気的に接続されるゲート配線１３を形成す
るとともに、ソース配線１０をＮ+ 型領域１６の一方に
電気的に接続し，ゲート配線１３をＮ+ 型領域１６の他
方に電気的に接続する。
以上の製造工程を経ることによりＭＯＳＦＥＴ１とソー
ス−ゲート間に接続された双方向性ダイオード２２で構
成される半導体装置の主要部が完成する。Next, an example of the manufacturing process of the semiconductor device is shown in FIG.
This will be described using (A) to (F). In the following description, the item symbols (A) to (B) indicate the items (A) to (B) in FIG.
It corresponds to each of (F). (A) After growing an N type epitaxial layer on the N + type semiconductor substrate 3 to form a drain region 4, a field insulating film 5 is formed on the surface of the drain region 4 by a thermal oxidation method. After selectively removing 5 by a photolithography method and an etching method, a gate insulating film 6 is formed on the exposed surface of the drain region 4 by a thermal oxidation method. (B) After covering the upper surfaces of these insulating films 5 and 6 with a polysilicon film 23 indicated by a broken line, the polysilicon film 23 is selectively removed by a photolithography method and an etching method to form a film on the field insulating film 5. Polysilicon block 24
And the gate electrode 7 is left on the gate insulating film 6. This gate electrode 7 is made low in resistance by ion implantation of phosphorus by using a resist film as a mask by a photolithography method. (C) Using the gate electrode 7 as a mask, the gate insulating film 6 is etched and boron ions are implanted into the opened window to form the P-type base region 8. At the same time, the entire surface of the polysilicon block 24 is ion-implanted with boron ions. Implant to form P-type region 25. (D) Using the resist film as a mask by the photolithography method, high-concentration boron is ion-implanted into the window opened at the central portion of the upper surface of the base region 8 to form the P + -type base contact region 9 and, at the same time, the P-type region. High-concentration boron is also ion-implanted into a window opened at the center of the upper surface of 25 to form a P + -type region 25a. In addition, a predetermined Zener breakdown voltage is obtained by controlling the opening size of the window in the central portion of the upper surface of the P-type region 25 (the length direction of the block 24). (E) Arsenic is ion-implanted into the opened window by using the resist film, which selectively covers the upper surface of the base contact region 9 and the gate electrode 7 as a mask by the photolithography method, to implant N
At the same time that the + source region 10 is formed, arsenic is ion-implanted into the windows opened at both ends of the P-type region 25 by using the resist film covering the upper surface of the P-type region 25 as a mask by the photolithography method to form the N + -type. Region 16 is formed. . (F) CV is formed on the upper surface of the semiconductor substrate 3 after the above steps are completed.
The interlayer insulating film 11 is deposited by the D method, and the source region 1 of the MOSFET 1 is processed by the photography method and the etching method.
0, a contact window is opened in the interlayer insulating film 11 between the base contact region 9 and the gate electrode 7 and the N + type region 16 of the bidirectional diode 22, and then an aluminum film is formed on the upper surface of the semiconductor substrate 3 by vacuum evaporation. And the aluminum film is selectively removed by a photolithography method and an etching method to be electrically connected to the source electrode 12 electrically connected to the source region 10 and the base contact region 9 and the gate electrode 7. The gate wiring 13 is formed, and the source wiring 10 is electrically connected to one of the N + type regions 16 and the gate wiring 13 is electrically connected to the other of the N + type regions 16. Through the above manufacturing steps, the main part of the semiconductor device including the MOSFET 1 and the bidirectional diode 22 connected between the source and the gate is completed.
【００１０】以上で説明したように、Ｐ+ ベースコンタ
クト領域９を形成するとき、従来は双方向性ダイオード
のＰ型領域をレジスト膜で全面被覆していたが、本発明
の半導体装置では、Ｐ型領域２５の中央部にレジスト膜
の開口された窓を設けることによって、この窓に同時に
高濃度のボロンがイオン注入されてＰ+ 型領域２５ａが
形成されるので、従来からの工程数を増やすことなく、
マスクの開口窓の寸法を変えることによりＰ+ 型領域２
５ａの寸法を制御でき、その結果、双方向性ダイード２
２のツェナー耐圧を容易に制御できる。また、このよう
にして形成された双方向性ダイオード２２は、Ｐ型領域
２５の中央部に濃度の高いＰ+ 型領域２５ａを形成する
ことにより、Ｐ型領域２５の抵抗がＰ+ 領域２５ａによ
り低抵抗化してツェナー波形の抵抗成分が減少すると共
に、Ｐ型領域２５とＮ+ 領域１６との接合部で生じる空
乏層の伸びがＰ+ 型領域２５ａで止まるため縦方向に形
成された接合部の表面部と内部とで空乏層幅が変わら
ず、ポリシリコン膜で形成しているにもかかわらず、ツ
ェナー波形をハード波形に近付けることが可能となる。
したがって、電流量の変化に対してツェナー耐圧値はほ
ぼ一定となり、ゲート定格から小さなマージンでツェナ
ー耐圧規格を設計でき、ＥＳＤ耐量の高い半導体装置を
提供することができる。なお、上記実施例では双方向性
ダイオード２２の接合部の数を片方向１個で説明したが
１個に限るものではなく、必要に応じて複数個でもよ
い。また、一導電型としてＰ型及び他導電型としてＮ型
で説明したが、一導電型としてＮ型及び他導電型として
Ｐ型であってもよい。また、ＭＯＳＦＥＴ１のゲート電
極７と双方向性ダイオード２２のＮ+ 型領域の他方とを
アルミニウムのゲート配線で電気的に接続したもので説
明しているが、双方向性ダイオード２２を構成するブロ
ック２４とゲート電極７を形成するときブロック２４の
Ｎ+ 型領域１６の他方側となる側をゲート電極７とポリ
シリコン膜で接続してもよい。また、ＭＯＳＦＥＴ１と
して縦型電界効果トランジスタで説明したが、縦型に限
るものではない。As described above, when the P + base contact region 9 is formed, the P type region of the bidirectional diode is conventionally entirely covered with the resist film, but in the semiconductor device of the present invention, By providing a window with an opening of the resist film in the center of the mold region 25, a high concentration of boron is simultaneously ion-implanted into this window to form the P + -type region 25a, so that the number of steps from the related art is increased. Without
P + type region 2 by changing the size of the opening window of the mask
The size of 5a can be controlled, and as a result, the interactive die 2
The Zener breakdown voltage of 2 can be easily controlled. In the bidirectional diode 22 thus formed, the P + region 25a having a high concentration is formed in the central portion of the P type region 25 so that the resistance of the P type region 25 is reduced by the P + region 25a. The resistance component is reduced to reduce the resistance component of the Zener waveform, and the extension of the depletion layer generated at the junction between the P type region 25 and the N + region 16 is stopped at the P + type region 25a. The width of the depletion layer does not change between the surface portion and the inside, and the Zener waveform can be approximated to the hard waveform even though it is formed of the polysilicon film.
Therefore, the Zener withstand voltage value becomes almost constant with respect to the change of the current amount, the Zener withstand voltage standard can be designed with a small margin from the gate rating, and the semiconductor device with high ESD withstand can be provided. Although the number of junctions of the bidirectional diode 22 is one in each direction in the above embodiment, the number is not limited to one and may be more than one if necessary. Further, the one conductivity type is the P type and the other conductivity type is the N type, but the one conductivity type may be the N type and the other conductivity type may be the P type. Further, the gate electrode 7 of the MOSFET 1 and the other of the N + type regions of the bidirectional diode 22 are electrically connected by the aluminum gate wiring in the description, but the block 24 constituting the bidirectional diode 22 is described. When the gate electrode 7 is formed, the other side of the N + type region 16 of the block 24 may be connected to the gate electrode 7 with a polysilicon film. Further, although the vertical field effect transistor has been described as the MOSFET 1, it is not limited to the vertical type.
【００１１】[0011]
【発明の効果】本発明によれば、ＭＯＳＦＥＴのＰ+ 型
ベースコンタクト領域形成時に双方向性ダイオードのＰ
型領域の中央部にＰ+ 型領域を形成したので、工程数を
増やすことなくツェナー耐圧を容易に制御可能となり、
コストの低い半導体装置を提供できるとともに、双方向
性ダイオードをポリシリコン膜で形成しているにもかか
わらず、ツェナー波形がハード波形に近付くので、電流
量の変化に対してツェナー耐圧値はほぼ一定となり、ゲ
ート定格から小さなマージンでツェナー耐圧規格を設計
でき、ＥＳＤ耐量の高い半導体装置を提供できる。According to the present invention, when the P + type base contact region of the MOSFET is formed, the P of the bidirectional diode P is formed.
Since the P + type region is formed in the center of the mold region, the Zener breakdown voltage can be easily controlled without increasing the number of steps,
It is possible to provide a low-cost semiconductor device, and the Zener waveform approaches a hard waveform even though the bidirectional diode is formed of a polysilicon film, so the Zener withstand voltage value is almost constant with changes in the current amount. Therefore, the Zener withstand voltage standard can be designed with a small margin from the gate rating, and a semiconductor device having a high ESD withstand can be provided.
【図１】 本発明の一実施例の半導体装置の断面図FIG. 1 is a sectional view of a semiconductor device according to an embodiment of the present invention.
【図２】 図１に示す半導体装置の製造工程を示す主要
部の断面図2 is a cross-sectional view of a main part showing a manufacturing process of the semiconductor device shown in FIG.
【図３】 従来の半導体装置の断面図FIG. 3 is a sectional view of a conventional semiconductor device.
Ｇ ゲート Ｓ ソース １ 電界効果型トランジスタ（ＭＯＳＦＥＴ） ３ Ｎ+ 型半導体基板 ４ Ｎ型ドレイン領域 ５ フィールド絶縁膜 ６ ゲート絶縁膜 ７ ゲート電極 ８ Ｐ型ベース領域 ９ Ｐ+ 型ベースコンタクト領域 １０ Ｎ+ 型ソース領域 １１ 層間絶縁膜 １６ Ｎ+ 型領域 ２２ 双方向性ダイオード ２３ ポリシリコン膜 ２４ ポリシリコンブロック ２５ Ｐ型領域 ２５ａ Ｐ+ 型領域G gate S source 1 field effect transistor (MOSFET) 3 N + type semiconductor substrate 4 N type drain region 5 field insulating film 6 gate insulating film 7 gate electrode 8 P type base region 9 P + type base contact region 10 N + type Source region 11 Interlayer insulating film 16 N + type region 22 Bidirectional diode 23 Polysilicon film 24 Polysilicon block 25 P type region 25a P + type region
Claims (3)
スタのゲート・ソース間に、前記半導体基板上の絶縁膜
中に形成した一導電型領域と他導電型領域とを含む双方
向性ダイオードを接続した半導体装置において、 前記ダイオードの他導電型領域の中央部に高濃度領域を
形成したことを特徴とする半導体装置。1. A bidirectional diode including one conductivity type region and another conductivity type region formed in an insulating film on the semiconductor substrate is connected between a gate and a source of a field effect transistor formed on a semiconductor substrate. In the semiconductor device described above, a high-concentration region is formed in the center of the other conductivity type region of the diode.
レイン領域を形成し、この領域上にフィールド絶縁膜と
ゲート絶縁膜とを形成する工程と、 前記フィールド絶縁膜及びゲート絶縁膜上にポリシリコ
ン膜を被覆し、このポリシリコン膜を選択的にエッチン
グして、前記フィールド絶縁膜上にポリシリコンブロッ
クと前記ゲート絶縁膜上にゲート電極とを同時に形成す
る工程と、 前記ブロックに他導電型領域と前記ドレイン領域に他導
電型ベース領域とを同時に形成する工程と、 前記ブロックの他導電型領域の中央部に高濃度他導電型
領域と前記ベース領域の中央部に高濃度他導電型ベース
コンタクト領域とを選択的に同時に形成する工程と、 前記ブロックの他導電型領域の両端部に高濃度一導電型
領域と前記ベース領域に高濃度一導電型ソース領域とを
同時に形成する工程とを含む電界効果型トランジスタの
ゲート・ソース間に前記ブロックに形成された双方向性
ダイオードを接続した半導体装置の製造方法。2. A step of forming a one-conductivity type drain region on a high-concentration one-conductivity type semiconductor substrate, and forming a field insulating film and a gate insulating film on the region, and on the field insulating film and the gate insulating film. A polysilicon film on the first insulating film and selectively etching the polysilicon film to simultaneously form a polysilicon block on the field insulating film and a gate electrode on the gate insulating film. Forming a conductivity type region and another conductivity type base region in the drain region at the same time; and a high concentration other conductivity type region in the center of the block other conductivity type region and a high concentration other conductivity in the center of the base region. A step of selectively forming a type base contact region at the same time, and a high concentration one conductivity type region at both ends of the other conductivity type region of the block and a high concentration one conductivity type in the base region. A method of manufacturing a semiconductor device, wherein a bidirectional diode formed in the block is connected between a gate and a source of a field effect transistor, the method including simultaneously forming a type source region.
寸法により前記ダイオードのツェナー耐圧を制御するこ
とを特徴とする請求項２記載の半導体装置の製造方法。3. The method of manufacturing a semiconductor device according to claim 2, wherein the Zener breakdown voltage of the diode is controlled by the length dimension of the high-concentration other conductivity type region of the block.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19326995A JP3489602B2 (en) | 1995-07-28 | 1995-07-28 | Semiconductor device and manufacturing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19326995A JP3489602B2 (en) | 1995-07-28 | 1995-07-28 | Semiconductor device and manufacturing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0945905A JPH0945905A (en) | 1997-02-14 |
| JP3489602B2 true JP3489602B2 (en) | 2004-01-26 |
Family
ID=16305136
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19326995A Expired - Fee Related JP3489602B2 (en) | 1995-07-28 | 1995-07-28 | Semiconductor device and manufacturing method thereof |
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| Country | Link |
|---|---|
| JP (1) | JP3489602B2 (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0945912A (en) * | 1995-07-31 | 1997-02-14 | Nec Corp | Semiconductor device and its manufacture |
| KR100267107B1 (en) * | 1998-09-16 | 2000-10-02 | 윤종용 | Semiconductor device and method for fabricating the same |
| KR100331540B1 (en) * | 2000-06-23 | 2002-04-06 | 김덕중 | MOS-type semiconductor device with electrostaticdischarge diode between gate and emitter |
| JP4857493B2 (en) * | 2000-07-12 | 2012-01-18 | 株式会社デンソー | Manufacturing method of semiconductor device |
| JP2006024601A (en) * | 2004-07-06 | 2006-01-26 | Seiko Instruments Inc | Field effect mos transistor |
| WO2011093472A1 (en) | 2010-01-29 | 2011-08-04 | 富士電機システムズ株式会社 | Semiconductor device |
| WO2014073656A1 (en) * | 2012-11-08 | 2014-05-15 | 富士電機株式会社 | Semiconductor device and semiconductor device fabrication method |
| CN106298681B (en) * | 2015-06-02 | 2019-03-29 | 北大方正集团有限公司 | A kind of MOSFET element and preparation method thereof |
| CN106298940A (en) * | 2016-08-30 | 2017-01-04 | 西安龙腾新能源科技发展有限公司 | The preparation method of VDMOS integrated ESD structure |
| CN116825850B (en) * | 2023-08-25 | 2023-11-17 | 江苏应能微电子股份有限公司 | Isolated gate trench MOS device integrated with ESD protection device and process |
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1995
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| JPH0945905A (en) | 1997-02-14 |
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