JPH065868A - Semiconductor device - Google Patents

Semiconductor device

Info

Publication number
JPH065868A
JPH065868A JP4160890A JP16089092A JPH065868A JP H065868 A JPH065868 A JP H065868A JP 4160890 A JP4160890 A JP 4160890A JP 16089092 A JP16089092 A JP 16089092A JP H065868 A JPH065868 A JP H065868A
Authority
JP
Japan
Prior art keywords
base layer
layer
type
source
impurity concentration
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.)
Withdrawn
Application number
JP4160890A
Other languages
Japanese (ja)
Inventor
Yasuhiro Koseki
康弘 小関
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 Yamagata Ltd
Original Assignee
NEC Yamagata 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 NEC Yamagata Ltd filed Critical NEC Yamagata Ltd
Priority to JP4160890A priority Critical patent/JPH065868A/en
Publication of JPH065868A publication Critical patent/JPH065868A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00Semiconductor 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
    • H01L29/66Types of semiconductor device ; Multistep manufacturing processes therefor
    • H01L29/68Types 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
    • H01L29/76Unipolar devices, e.g. field effect transistors
    • H01L29/772Field effect transistors
    • H01L29/78Field effect transistors with field effect produced by an insulated gate
    • H01L29/7801DMOS transistors, i.e. MISFETs with a channel accommodating body or base region adjoining a drain drift region
    • H01L29/7802Vertical DMOS transistors, i.e. VDMOS transistors
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00Semiconductor 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
    • H01L29/02Semiconductor bodies ; Multistep manufacturing processes therefor
    • H01L29/06Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions
    • H01L29/10Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions with semiconductor regions connected to an electrode not carrying current to be rectified, amplified or switched and such electrode being part of a semiconductor device which comprises three or more electrodes
    • H01L29/1095Body region, i.e. base region, of DMOS transistors or IGBTs

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)
  • Insulated Gate Type Field-Effect Transistor (AREA)

Abstract

PURPOSE:To improve the breakdown resistance of a vertical doubly diffused MOSFET against the counter electromotive force surge specific to inductive load. CONSTITUTION:A semiconductor device is provided with a P<-> type first base layer 6 provided on a drain layer 5, a P<+> type second base layer 9 provided at the center of the surface of the first base layer, an N<-> type source layer 7 provided at the circumference of the second base layer 9 and a P type third base layer 8 which is connected to the bottom of the second base layer 9 and extends to the bottom of the source layer 7.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は半導体装置に関し、特に
縦型二重拡散MOSFETを有する半導体装置に関す
る。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, and more particularly to a semiconductor device having a vertical double diffusion MOSFET.

【0002】[0002]

【従来の技術】従来の縦型二重拡散MOSFETは、図
3に示すように、N+ 型のドレイン層4とこの上にエピ
タキシャル成長法によって形成されたN- 型のドレイン
層5とからなる半導体基板に、ゲート・チャネル領域と
なるP- 型の第1のベース層6を設け、この第1のベー
ス層6の表面にN型のソース層7と誘導性負荷特有の逆
起電力サージによる破壊を防止するためにP+ 型の第2
のベース層9をソース層7とほぼ同じ拡散層深さで形成
し、更にその上にゲート酸化膜10及び多結晶シリコン
を用いたゲート電極3を形成し、このゲート酸化膜10
及びゲート電極3をソース層7の一部と第2のベース層
9の部分で開孔し、ゲート電極3上に層間絶縁膜11を
設け、この部分でソース層7の一部と第2のベース層9
が接触するようにソース電極2を形成し、ソース電極2
上に表面保護膜12を形成し、また下面にドレイン電極
1を形成した構造となっている。
2. Description of the Related Art As shown in FIG. 3, a conventional vertical double diffusion MOSFET is a semiconductor including an N + type drain layer 4 and an N type drain layer 5 formed thereon by an epitaxial growth method. The substrate is provided with a P -type first base layer 6 serving as a gate / channel region, and the surface of the first base layer 6 is destroyed by an N-type source layer 7 and a counter electromotive force surge peculiar to an inductive load. P + type second to prevent
Of the source layer 7 is formed to a depth almost equal to that of the source layer 7, and a gate oxide film 10 and a gate electrode 3 made of polycrystalline silicon are further formed thereon.
And the gate electrode 3 is opened in a part of the source layer 7 and the second base layer 9, and an interlayer insulating film 11 is provided on the gate electrode 3, and in this part, a part of the source layer 7 and the second base layer 9 are formed. Base layer 9
Source electrode 2 is formed so that
The surface protection film 12 is formed on the upper surface, and the drain electrode 1 is formed on the lower surface.

【0003】[0003]

【発明が解決しようとする課題】上述した従来の半導体
装置は、第2のベース層9がソース層7とほぼ同じ深さ
の拡散層であるため、ドレイン層5と第1のベース層6
及び第2のベース層9とソース層7とで寄生NPNトラ
ンジスタが形成される。この寄生NPNトランジスタに
おいては、第1のベース層の不純物濃度が低いためhFE
が高まって導通しやすくなり、誘導性負荷に対する破壊
耐量が十分に得られなかった。
In the conventional semiconductor device described above, since the second base layer 9 is a diffusion layer having substantially the same depth as the source layer 7, the drain layer 5 and the first base layer 6 are formed.
A parasitic NPN transistor is formed by the second base layer 9 and the source layer 7. In this parasitic NPN transistor, since the impurity concentration of the first base layer is low, h FE
Was increased to facilitate conduction, and a sufficient breakdown resistance against an inductive load could not be obtained.

【0004】また、この誘導性負荷に対する破壊耐量を
向上させるために、前記寄生NPNトランジスタのhFE
を低減させて導通しにくくするように第1のベース層6
の不純物濃度を高くした場合、ゲート・チャネル領域と
なる基板表面付近の不純物濃度、すなわちチャネル濃度
も同様に高くなり、MOSFETを導通状態にするため
にゲート・ソース間に印加するしきい値電圧VGS(Off)
が大きくなるという問題点があった。
[0004] In order to improve the breakdown voltage for the inductive load, h FE of the parasitic NPN transistor
The first base layer 6 so as to reduce
When the impurity concentration of is increased, the impurity concentration in the vicinity of the surface of the substrate that becomes the gate / channel region, that is, the channel concentration is also increased, and the threshold voltage V applied between the gate and the source to bring the MOSFET into a conductive state is increased. GS (Off)
However, there was a problem that

【0005】[0005]

【課題を解決するための手段】本発明の半導体装置は、
ドレイン層となる第1導電型の半導体基板と、この半導
体基板内に設けられゲート・チャネル領域となる不純物
濃度の低い第2導電型の第1のベース層と、この第1の
ベース層表面の中央部に設けられ不純物濃度の高い第2
導電型の第2のベース層と、前記第1のベース層表面の
前記第2のベース層の周囲に設けられ第2のベース層と
ほぼ同じ厚さに形成された第1導電型のソース層と、前
記第1のベース層内に設けられ前記第2のベース層の下
部に接続し前記ソース層の下部に延在して形成された不
純物濃度の高い第2導電型の第3のベース層とを含むも
のである。
The semiconductor device of the present invention comprises:
A first conductivity type semiconductor substrate which becomes a drain layer, a second conductivity type first base layer which is provided in the semiconductor substrate and has a low impurity concentration which becomes a gate / channel region, and a surface of the first base layer. 2nd with high impurity concentration
A conductive type second base layer, and a first conductive type source layer provided on the surface of the first base layer around the second base layer and formed to have substantially the same thickness as the second base layer. And a third base layer of a second conductivity type having a high impurity concentration, which is provided in the first base layer, is connected to a lower portion of the second base layer, and is extended to a lower portion of the source layer. It includes and.

【0006】[0006]

【実施例】次に、本発明について図面を参照して説明す
る。図1は本発明の一実施例のNチャネル型MOSFE
Tを示す断面図である。
DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 shows an N-channel type MOSFE according to an embodiment of the present invention.
It is sectional drawing which shows T.

【0007】図1に示すように、N+ 型のドレイン層4
と、この上にエピタキシャル成長法によって形成された
- 型のドレイン層5とからなる半導体基板に、ゲート
酸化膜10と多結晶シリコンを用いたゲート電極3を形
成したのち開孔し、この開孔部を用いてゲート・チャネ
ル領域となるP- 型の第1のベース層6を形成する。次
に、誘導性負荷に対する破壊耐量を向上させるためのP
型の第3のベース層8を形成し、続いてN型のソース層
7とその中央部にP+ 型の第2のベース層9を形成す
る。
As shown in FIG. 1, the N + type drain layer 4 is formed.
Then, a gate oxide film 10 and a gate electrode 3 made of polycrystalline silicon are formed on a semiconductor substrate composed of an N -type drain layer 5 formed thereon by an epitaxial growth method, and then a hole is formed. The P -type first base layer 6 to be the gate channel region is formed by using the portion. Next, P for improving the fracture resistance against inductive loads
The third type base layer 8 is formed, and then the N type source layer 7 and the P + type second base layer 9 are formed in the central portion thereof.

【0008】この場合、第3のベース層8は第2のベー
ス層9の下部で第2のベース層に接続し、しかもソース
層7の下部に延在するように構成する。次に、ゲート電
極3上に層間絶縁膜11を形成し、ソース層7の一部及
び第2のベース層9上で層間絶縁膜11を開孔し、ソー
ス電極2を形成する。次に、表面保護膜12を形成し、
最後に基板裏面にドレイン電極1を形成する。
In this case, the third base layer 8 is constructed so as to be connected to the second base layer below the second base layer 9 and extend below the source layer 7. Next, the interlayer insulating film 11 is formed on the gate electrode 3, and the interlayer insulating film 11 is opened on a part of the source layer 7 and the second base layer 9 to form the source electrode 2. Next, the surface protective film 12 is formed,
Finally, the drain electrode 1 is formed on the back surface of the substrate.

【0009】このように構成された本実施例によれば、
第3のベース層8がソース層7及び第2のベース層9よ
りも拡散層の深さが深いため、ドレイン層5と第1,第
2,第3のベース層6,9,8とソース層7で形成され
る寄生NPNトランジスタにおいて、ベース層部分の不
純物濃度が高いため、hFEが低減して導通しにくくな
り、誘導性負荷に対する破壊耐量が向上する。
According to the present embodiment thus constructed,
Since the third base layer 8 has a deeper diffusion layer than the source layer 7 and the second base layer 9, the drain layer 5 and the first, second, third base layers 6, 9, 8 and the source In the parasitic NPN transistor formed by the layer 7, since the impurity concentration of the base layer portion is high, h FE is reduced and it becomes difficult to conduct electricity, and the breakdown resistance against an inductive load is improved.

【0010】また、本実施例によれば、ゲート・チャネ
ル領域となる基板表面付近の不純物濃度、すなわちチャ
ネル濃度は、第1のベース層6により維持されたままで
あり、MOSFETを導通状態にするためにゲート・ソ
ース間に印加するしきい値電圧VGS(Off) を大きくする
ことなく、誘導性負荷に対する破壊耐量を向上させるこ
とができる。
Further, according to this embodiment, the impurity concentration in the vicinity of the surface of the substrate which becomes the gate / channel region, that is, the channel concentration is maintained by the first base layer 6 to keep the MOSFET in the conductive state. It is possible to improve the breakdown resistance against an inductive load without increasing the threshold voltage V GS (Off) applied between the gate and the source.

【0011】図2は、誘導性負荷耐量と定格電流I
D(DC) の関係を表しており、縦軸に誘導性負荷耐量、横
軸に定格電流を示している。この図2において、黒点が
本実施例による場合、白点が従来の構造による場合であ
る。図2から明らかなように、従来の半導体装置に比べ
本実施例では誘導性負荷耐量が50%向上していること
がわかる。
FIG. 2 shows inductive load capacity and rated current I.
It shows the relationship of D (DC) , in which the vertical axis shows the inductive load capacity and the horizontal axis shows the rated current. In FIG. 2, the black dots represent the case of this embodiment and the white dots represent the case of the conventional structure. As is apparent from FIG. 2, the inductive load withstand amount is improved by 50% in this embodiment as compared with the conventional semiconductor device.

【0012】[0012]

【発明の効果】以上説明したように本発明は、縦型二重
拡散MOSFETにおいて、第1のベース層表面に形成
された第2のベース層の下に、ソース層及び第2のベー
ス層よりも深い第3のベース層を形成することにより、
誘導性負荷に対する破壊耐量を向上させることができる
という効果を有する。さらに、本発明によれば、しきい
値電圧VGS(Off) を大きくすることなく誘導性負荷に対
する破壊耐量を向上させることができる。
As described above, according to the present invention, in a vertical double diffusion MOSFET, a source layer and a second base layer are provided below a second base layer formed on the surface of the first base layer. By forming a deeper third base layer,
It has an effect that it is possible to improve the breakdown resistance against an inductive load. Furthermore, according to the present invention, it is possible to improve the breakdown withstanding load against an inductive load without increasing the threshold voltage V GS (Off) .

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

【図1】本発明の一実施例を示す半導体チップの断面
図。
FIG. 1 is a sectional view of a semiconductor chip showing an embodiment of the present invention.

【図2】本実施例と従来例の誘導性負荷耐量と定格電流
の関係を示す図。
FIG. 2 is a diagram showing a relationship between an inductive load withstanding capacity and a rated current in this example and a conventional example.

【図3】従来の半導体装置の一例を示す半導体チップの
断面図。
FIG. 3 is a sectional view of a semiconductor chip showing an example of a conventional semiconductor device.

【符号の説明】[Explanation of symbols]

1 ドレイン電極 2 ソース電極 3 ゲート電極 4 ドレイン層 5 ドレイン層 6 第1のベース層 7 ソース層 8 第3のベース層 9 第2のベース層 10 ゲート酸化膜 11 層間絶縁膜 12 表面保護膜 1 Drain Electrode 2 Source Electrode 3 Gate Electrode 4 Drain Layer 5 Drain Layer 6 First Base Layer 7 Source Layer 8 Third Base Layer 9 Second Base Layer 10 Gate Oxide Film 11 Interlayer Insulating Film 12 Surface Protective Film

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】 ドレイン層となる第1導電型の半導体基
板と、この半導体基板内に設けられゲート・チャネル領
域となる不純物濃度の低い第2導電型の第1のベース層
と、この第1のベース層表面の中央部に設けられ不純物
濃度の高い第2導電型の第2のベース層と、前記第1の
ベース層表面の前記第2のベース層の周囲に設けられ第
2のベース層とほぼ同じ厚さに形成された第1導電型の
ソース層と、前記第1のベース層内に設けられ前記第2
のベース層の下部に接続し前記ソース層の下部に延在し
て形成された不純物濃度の高い第2導電型の第3のベー
ス層とを含むことを特徴とする半導体装置。
1. A first-conductivity-type semiconductor substrate serving as a drain layer, a second-conductivity-type first base layer having a low impurity concentration, which is provided in the semiconductor substrate and serves as a gate channel region, and the first-conductivity-type first base layer. Second conductive type second base layer provided in the central portion of the base layer surface and having a high impurity concentration, and a second base layer provided around the second base layer on the first base layer surface. A source layer of the first conductivity type formed to have substantially the same thickness as that of the second conductive layer, and the second layer provided in the first base layer.
A second conductive type third base layer having a high impurity concentration, which is formed so as to be connected to the lower part of the base layer and extend to the lower part of the source layer.
JP4160890A 1992-06-19 1992-06-19 Semiconductor device Withdrawn JPH065868A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP4160890A JPH065868A (en) 1992-06-19 1992-06-19 Semiconductor device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP4160890A JPH065868A (en) 1992-06-19 1992-06-19 Semiconductor device

Publications (1)

Publication Number Publication Date
JPH065868A true JPH065868A (en) 1994-01-14

Family

ID=15724583

Family Applications (1)

Application Number Title Priority Date Filing Date
JP4160890A Withdrawn JPH065868A (en) 1992-06-19 1992-06-19 Semiconductor device

Country Status (1)

Country Link
JP (1) JPH065868A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997016853A1 (en) * 1995-11-02 1997-05-09 National Semiconductor Corporation Insulated gate semiconductor devices with implants for improved ruggedness
US5701023A (en) * 1994-08-03 1997-12-23 National Semiconductor Corporation Insulated gate semiconductor device typically having subsurface-peaked portion of body region for improved ruggedness

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5701023A (en) * 1994-08-03 1997-12-23 National Semiconductor Corporation Insulated gate semiconductor device typically having subsurface-peaked portion of body region for improved ruggedness
US5897355A (en) * 1994-08-03 1999-04-27 National Semiconductor Corporation Method of manufacturing insulated gate semiconductor device to improve ruggedness
WO1997016853A1 (en) * 1995-11-02 1997-05-09 National Semiconductor Corporation Insulated gate semiconductor devices with implants for improved ruggedness

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Effective date: 19990831