CN108470767A - 氮化物半导体器件 - Google Patents

氮化物半导体器件 Download PDF

Info

Publication number
CN108470767A
CN108470767A CN201810123384.4A CN201810123384A CN108470767A CN 108470767 A CN108470767 A CN 108470767A CN 201810123384 A CN201810123384 A CN 201810123384A CN 108470767 A CN108470767 A CN 108470767A
Authority
CN
China
Prior art keywords
region
semiconductor substrate
electrode
source
drain
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Withdrawn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
CN201810123384.4A
Other languages
English (en)
Inventor
渡部敦
上田博之
森朋彦
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.)
Toyota Motor Corp
Original Assignee
Toyota Motor 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 Toyota Motor Corp filed Critical Toyota Motor Corp
Publication of CN108470767A publication Critical patent/CN108470767A/zh
Withdrawn legal-status Critical Current

Links

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
    • H01L29/778—Field effect transistors with two-dimensional charge carrier gas channel, e.g. HEMT ; with two-dimensional charge-carrier layer formed at a heterojunction interface
    • 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
    • H01L29/778—Field effect transistors with two-dimensional charge carrier gas channel, e.g. HEMT ; with two-dimensional charge-carrier layer formed at a heterojunction interface
    • H01L29/7788—Vertical transistors
    • 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
    • H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
    • H01L29/06—Semiconductor 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
    • H01L29/0657—Semiconductor 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 characterised by the shape of the body
    • 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
    • H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
    • H01L29/06—Semiconductor 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
    • H01L29/10—Semiconductor 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
    • H01L29/1025—Channel region of field-effect devices
    • H01L29/1029—Channel region of field-effect devices of field-effect transistors
    • H01L29/1033—Channel region of field-effect devices of field-effect transistors with insulated gate, e.g. characterised by the length, the width, the geometric contour or the doping structure
    • H01L29/1041—Channel region of field-effect devices of field-effect transistors with insulated gate, e.g. characterised by the length, the width, the geometric contour or the doping structure with a non-uniform doping structure in the channel region surface
    • H01L29/1045—Channel region of field-effect devices of field-effect transistors with insulated gate, e.g. characterised by the length, the width, the geometric contour or the doping structure with a non-uniform doping structure in the channel region surface the doping structure being parallel to the channel length, e.g. DMOS like
    • 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
    • H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
    • H01L29/12—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by the materials of which they are formed
    • H01L29/20—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by the materials of which they are formed including, apart from doping materials or other impurities, only AIIIBV compounds
    • H01L29/2003—Nitride compounds
    • 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
    • H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
    • H01L29/12—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by the materials of which they are formed
    • H01L29/20—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by the materials of which they are formed including, apart from doping materials or other impurities, only AIIIBV compounds
    • H01L29/201—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by the materials of which they are formed including, apart from doping materials or other impurities, only AIIIBV compounds including two or more compounds, e.g. alloys
    • H01L29/205—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by the materials of which they are formed including, apart from doping materials or other impurities, only AIIIBV compounds including two or more compounds, e.g. alloys in different semiconductor regions, e.g. heterojunctions
    • 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
    • H01L29/40—Electrodes ; Multistep manufacturing processes therefor
    • H01L29/41—Electrodes ; Multistep manufacturing processes therefor characterised by their shape, relative sizes or dispositions
    • H01L29/417—Electrodes ; Multistep manufacturing processes therefor characterised by their shape, relative sizes or dispositions carrying the current to be rectified, amplified or switched
    • H01L29/41725—Source or drain electrodes for field effect devices
    • H01L29/41766—Source or drain electrodes for field effect devices with at least part of the source or drain electrode having contact below the semiconductor surface, e.g. the source or drain electrode formed at least partially in a groove or with inclusions of conductor inside the semiconductor
    • 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
    • H01L29/778—Field effect transistors with two-dimensional charge carrier gas channel, e.g. HEMT ; with two-dimensional charge-carrier layer formed at a heterojunction interface
    • H01L29/7782—Field effect transistors with two-dimensional charge carrier gas channel, e.g. HEMT ; with two-dimensional charge-carrier layer formed at a heterojunction interface with confinement of carriers by at least two heterojunctions, e.g. DHHEMT, quantum well HEMT, DHMODFET
    • H01L29/7783—Field effect transistors with two-dimensional charge carrier gas channel, e.g. HEMT ; with two-dimensional charge-carrier layer formed at a heterojunction interface with confinement of carriers by at least two heterojunctions, e.g. DHHEMT, quantum well HEMT, DHMODFET using III-V semiconductor material
    • 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
    • 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

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)
  • Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Electrodes Of Semiconductors (AREA)
  • Junction Field-Effect Transistors (AREA)

Abstract

一种氮化物半导体器件，具备半导体衬底、源电极、漏电极以及隔着栅极绝缘膜设置于半导体衬底上的栅电极。半导体衬底具有由GaN构成的第一部分以及由AlxGa(1‑X)N(0＜x≤1)构成的第二部分。第一部分具有：n型源区，与源电极接触；n型漏区，与漏电极接触；p型体区，介于源区与漏区之间并且与源电极接触；以及n型漂移区，介于体区与漏区之间并且载流子浓度低于漏区。第二部分具有势垒区，该势垒区与源电极、体区以及漂移区分别接触。

Description

氮化物半导体器件
技术领域
本说明书中公开的技术涉及氮化物半导体器件。
背景技术
在日本特开2007-59636号公报中公开了具有GaN(氮化镓)半导体衬底的半导体器件。在所述半导体衬底上形成有金属氧化物半导体场效应晶体管(MOSFET，Metal-Oxide-Semiconductor Field-Effect Transistor)的元件结构。详细而言，在半导体衬底中设置有：n型源区，该n型源区与源电极接触；n型漏区，该n型漏区与漏电极接触；p型体区，该p型体区介于源区与漏区之间且与源电极接触；以及n型漂移区，该n型漂移区介于体区与漏区之间并且载流子浓度低于漏区。而且，该半导体器件被构成为：栅电极隔着栅极绝缘膜面向位于源区与漂移区之间的体区，当对栅电极与源电极之间施加驱动电压时，形成在源区与漂移区之间延伸的n型沟道。
发明内容
GaN、SiC(碳化硅)是具有比Si(硅)宽的宽带隙的半导体材料。这种半导体材料被称为宽带隙半导体，被积极地用于半导体器件作为替代Si的半导体材料。然而，将GaN和SiC进行比较，GaN的热导率低于SiC。由此，在使用GaN的半导体器件中，当半导体衬底(即，GaN)由于通电而发热时，难以使半导体衬底充分地散热，其结果，存在导致半导体衬底过热的风险。为了防止半导体衬底的过热，有考虑限制在半导体衬底中流过的电流，但以这样的措施不能充分地利用GaN的优点(例如，漂移区的尺寸减小带来的损耗降低)。
考虑到上述事项，在本说明书中提供能够提高包含GaN的半导体衬底的散热性的技术。
本技术公开了半导体器件。该半导体器件具备：半导体衬底，所述半导体衬底具有氮化物半导体；源电极及漏电极，所述源电极及漏电极分别设置于半导体衬底上；以及栅电极，所述栅电极隔着栅极绝缘膜设置于半导体衬底上。半导体衬底具有由GaN构成的第一部分以及由AlxGa(1-X)N(0＜x≤1)构成的第二部分。第一部分具有：n型源区，所述n型源区与源电极接触；n型漏区，所述n型漏区与漏电极接触；p型体区，所述p型体区介于源区与漏区之间并且与源电极接触；以及n型漂移区，所述n型漂移区介于体区与漏区之间并且载流子浓度低于漏区。第二部分具有势垒区，所述势垒区与源电极、体区以及漂移区分别接触。
在半导体衬底中，伴随通电的发热主要在漂移区产生。漂移区由GaN构成，因此漂移区的热难以向外部释放。关于这方面，在上述结构中，由AlxGa(1-x)N构成的势垒区与漂移区和源电极这两者接触。AlxGa(1-x)N具有比GaN高的热导率。例如，GaN的热导率为1.30W/(cm·K)，与此相对，AlN(即，x＝1)的热导率为2.85W/(cm·K)。因此，在漂移区产生的热通过势垒区向源电极迅速地传递，由此防止或抑制了半导体衬底的过热。
而且，根据上述结构，在由AlxGa(1-X)N构成的势垒区与由p型GaN构成的体区之间的界面产生二维空穴气。由此，例如当对漂移区施加高电场并且在漂移区内发生碰撞电离时，因碰撞电离产生的空穴通过二维空穴气向源电极迅速地排出。由此，碰撞电离的雪崩式的增大被抑制，半导体器件的雪崩耐量得到提高。
进而，根据上述结构，在由AlxGa(1-X)N构成的势垒区与由n型GaN构成的漂移区之间的界面产生二维电子气。在二维电子气中电子迁移率高，因此当电子从源电极经过漂移区向漏电极流动时，在漂移区产生的能量损失减少。因此，在半导体器件的导通电阻减少的同时，漂移区中的发热量也减少。
附图说明
图1示意性地表示实施例的半导体器件10的结构。
图2示意性地表示势垒区30带来的来自漂移区28的散热。
图3示意性地表示二维空穴气2DHG带来的来自漂移区28的空穴的排出。
具体实施方式
在本技术的一实施方式中，构成半导体器件的第二部分(即，势垒区)的AlxGa(1-X)N可以是AlN(氮化铝)。即，可以是X＝1。在AlxGa(1-X)N中，Al(铝)的含有率越高，其热导率也越高。因此，为了提高势垒区带来的散热性，优选提高势垒区中的Al的含有率，尤其AlN具有能够实现足够的散热性的高热导率。
在本技术的一实施方式中，半导体衬底可以具有第一表面，源区、体区以及漂移区分别在该第一表面处露出。而且，栅电极可以隔着栅极绝缘膜面向第一表面上的在源区与漂移区之间扩展的体区。由此，半导体器件能够具有平面型栅结构。作为其它实施方式，半导体器件也可以具有例如沟槽型栅结构等其它的栅结构。
在上述实施方式中，半导体衬底可以进一步具有第二表面，该第二表面位于第一表面的相反侧，并且漏区在该第二表面处露出。而且，源电极可以设置于第一表面上，漏电极可以设置于第二表面上。由此，半导体器件能够具有纵型MOSFET结构。作为其它实施方式，半导体器件通过源电极和漏电极这两者位于半导体衬底的同侧，从而可以具有横型MOSFET结构。
下面，参照附图详细地说明本发明的代表性且非限定性的具体例。该详细的说明旨在仅向本领域技术人员展示用于实施本发明的优选例的详细内容，并非限定本发明的范围。另外，为了将进一步改善的氮化物半导体器件与其制造方法及使用方法一起提供，以下公开的追加的特征及发明能够与其它特征、发明分开使用或者一起使用。
另外，在以下详细的说明中公开的特征、工序的组合就其最广义而言，不是实施本发明时必须的，是仅用于特别说明本发明的代表性具体例而记载的。进而，在提供本发明的追加且有用的实施方式时，上述及下述代表性具体例的各种特征以及独立权利要求和从属权利要求中记载的各种特征并非必须按照此处记载的具体例或者所列举的顺序进行组合。
与实施例和/或权利要求中记载的特征的构成独立地，在本说明书和/或权利要求中记载的所有特征，旨在作为针对原始申请的公开以及所要求保护的特定事项的限定而单独地且彼此独立地公开。进而，所有关于数值范围和组或集的记载作为针对原始申请的公开以及所要求保护的特定事项的限定，旨在公开其中间的构成。
参照附图说明实施例的半导体器件10。半导体器件10是使用氮化物半导体的氮化物半导体器件。半导体器件10是功率半导体器件的一种，能够应用于例如用于驱动车辆的马达的电源电路中的逆变器、转换器。需要说明的是，在本实施例中说明的技术要素不限于本实施例的半导体器件10，还能够适用于其它各种半导体器件。
图1具有半导体器件10的单元结构。在半导体器件10中，沿图1中的左右方向重复形成有图1所示的单元结构。如图1所示，半导体器件10具备：半导体衬底12；源电极14和漏电极16，所述源电极14和漏电极16分别设置于半导体衬底12上；栅电极18，所述栅电极18隔着栅极绝缘膜20设置于半导体衬底12上。
半导体衬底12是所谓的氮化物半导体衬底，如后所述，在其至少一部分中具有氮化物半导体。半导体衬底12具有上表面12a以及位于上表面12a相反侧的下表面12b。上表面12a是本公开中的第一表面的一例，下表面12b是本公开中的第二表面的一例。作为一例，上表面12a可具有台面部12m以及位于台面部12m两侧的沟槽部12t。台面部12m相对于沟槽部12t凸出。换言之，沟槽部12t相对于台面部12m凹陷，位于相邻的两个台面部12m之间。
源电极14位于半导体衬底12的上表面12a上。作为一例，源电极14设置于沟槽部12t内，并且其两端位于台面部12m上。另一方面，漏电极16位于半导体衬底12的下表面12b上。即，本实施例的半导体器件10是源电极14和漏电极16分布于半导体衬底12两侧的纵型半导体器件。作为其它实施方式，半导体器件10也可以是源电极14和漏电极16配置在半导体衬底12同侧的横型半导体器件。源电极14和漏电极16分别由导电材料形成。虽没有特别限制，源电极14和漏电极16的材料例如可以是铝或铝合金等金属材料。另外，源电极14和漏电极16可以分别由单一材料形成，也可以具有由不同材料形成的层叠结构。源电极14和漏电极16例如可由溅射形成。
栅电极18和栅极绝缘膜20位于半导体衬底12的上表面12a上，栅电极18隔着栅极绝缘膜20面向半导体衬底12的上表面12a。作为一例，栅电极18和栅极绝缘膜20设置于台面部12m上，栅电极18隔着栅极绝缘膜20面向台面部12m。栅电极18由导电材料形成，栅极绝缘膜20由绝缘材料形成。虽没有特别限制，栅电极18的材料可以是多晶硅，栅极绝缘膜20可以是硅氧化物。栅电极18和栅极绝缘膜20例如可由CVD(化学气相沉积，Chemical VaporDeposition)形成。如此，本实施例的半导体器件10具有平面型栅结构。然而，作为其它实施方式，半导体器件10也可以具有沟槽型栅结构。
半导体衬底12具有由GaN(氮化镓)构成的第一部分22、24、26、28以及由AlN(氮化铝)构成的第二部分30。需要说明的是，第二部分30如后所述不限于AlN，可以由AlxGa(1-X)N(0＜x≤1)构成。第一部分22、24、26、28具有n型源区22、n型漏区24、p型体区26以及n型漂移区28。此处所谓的n型区是指掺杂了n型杂质的区域，表示多数载流子为电子的半导体区。另外，p型区是掺杂了p型杂质的区域，表示多数载流子为空穴的半导体区。
源区22在半导体衬底12的上表面12a处露出，并与源电极14接触。源区22的杂质浓度足够高，源电极14对源区22形成欧姆接触。作为一例，源区22位于台面部12m的角部，源电极14从两个方向对源区22形成接触。即，构成沟槽接触结构。漏区24在半导体衬底12的下表面12b处露出，并与漏电极16接触。漏区24的杂质浓度足够高，漏电极16对漏区24形成欧姆接触。
体区26介于源区22与漂移区28之间，漂移区28介于体区26与漏区24之间。换言之，体区26将源区22与漂移区28彼此隔开，并且与源区22和漂移区28分别接触。漂移区28将体区26和漏区24彼此隔开，并且与体区26和漏区24分别接触。体区26和漂移区28与源区22一起在半导体衬底12的上表面12a处露出。而且，栅电极18隔着栅极绝缘膜20面向半导体衬底12的上表面12a上的在源区22与漂移区28之间扩展的体区26。另外，体区26在半导体衬底12的上表面12a的沟槽部12t处还与源电极14接触。
通过以上构成，当对栅电极18与源电极14之间施加驱动电压时，在体区26内形成n型沟道C，该n型沟道C在源区22与漂移区28之间延伸。其结果，在源电极14与漏电极16之间建立电导通。即，半导体衬底12的第一部分22、24、26、28与栅电极18和栅极绝缘膜20一起形成MOSFET。而且，当对栅电极18与源电极14之间施加驱动电压时，该MOSFET被接通。而且，相邻的两个体区26和位于它们之间的漂移区28的一部分28a形成JFET(结栅场效应晶体管，Junction Gate Field-Effect Transistor)结构，使半导体器件10的耐压性提高。即，所述半导体器件10被构成为：当半导体器件10的MOSFET被接通、并且对体区26与漂移区28之间的pn接合面施加反向偏置电压时，位于两个体区26之间的漂移区28的一部分28a被迅速地耗尽。
在半导体衬底12的第一部分22、24、26、28中，利用体区26、漂移区28以及漏区24在源电极14与漏电极16之间形成pn结型二极管。该二极管容许从源电极14流向漏电极16的电流，并禁止从漏电极16流向源电极14的电流。二极管与前述MOSFET并联连接并且能够起续流二极管的作用。
本实施例的半导体器件10主要使用GaN构成。GaN与SiC一起作为具有比Si宽的宽带隙的半导体材料为人所知。这种半导体材料被称为宽带隙半导体，与Si相比具有许多优异的特征。然而，将GaN和SiC进行比较，GaN的热导率低于SiC。因此，在使用GaN的现有半导体器件中，当半导体衬底(即，GaN)由于通电而发热时，难以使半导体衬底充分地散热，其结果，存在导致半导体衬底过热的风险。为了防止半导体衬底的过热，有考虑限制在半导体衬底中流动的电流，但以这样的措施不能充分地利用GaN的优点(例如，漂移区的尺寸减小带来的损耗降低)。
关于上述方面，在本实施例的半导体器件10中，半导体衬底12不仅具有由GaN构成的第一部分22、24、26、28，进一步具有由AlN构成的第二部分30。第二部分30的一部分或全部构成下述势垒区30。势垒区30与源电极14、体区26以及漂移区28分别接触。构成势垒区30的AlN是没有掺杂杂质的未掺杂AlN，在半导体器件10中具有足够的电绝缘性。
在半导体衬底12中，伴随通电的发热主要在漂移区28中产生。因此，为了防止或抑制半导体衬底12的过热，需要使在漂移区28中产生的热迅速地向半导体衬底12的外部释放。关于这方面，通过势垒区30与源电极14和漂移区28这两者接触，源电极14和漂移区28经由势垒区30被热连接。构成势垒区30的AlN具有比构成源区22、体区26的GaN高的热导率。例如，GaN的热导率为1.30W/(cm·K)，与此相对，AlN(即，x＝1)的热导率为2.85W/(cm·K)。因此，如图2所示，在漂移区28中产生的热通过势垒区30向源电极14迅速地传递，并被释放到半导体衬底12的外部。此处，图2中的多个箭头T作为参考示意性地表示热的流动。
第二部分30(即，势垒区30)的材料不限于AlN，可以是AlxGa(1-X)N(0＜x≤1)。AlxGa(1-X)N由于具有高于GaN的热导率，因此与上述AlN同样地，能够促进从漂移区28向源电极14的散热。对于AlxGa(1-X)N，Al的含有率越高，其热导率也越高。因此，为了提高势垒区30带来的散热性，优选提高势垒区30中的Al的含有率，更优选AlN(即，x＝1)。而且，对于AlxGa(1-X)N(0＜x≤1)，Al的含有率越高，其带隙越大。因此，通过提高势垒区30中的Al的含有率，还能够提高势垒区30的绝缘性。
AlxGa(1-X)N具有与GaN相同的晶体结构。因此，由AlxGa(1-X)N构成的第二部分30与由GaN构成的第一部分22、24、26、28一起容易形成在同一半导体衬底12内。作为一例，第二部分30(即，势垒区30)能够通过外延生长形成在由GaN构成的漂移区28上。另外，能够使由GaN构成的体区26通过外延生长形成在第二部分30(即，势垒区30)上。需要说明的是，对于源区22和漂移区28虽然没有特别限制，但也可通过外延生长和蚀刻来形成。
进而，如图3所示，在本实施例的半导体器件10中，在由AlN构成的势垒区30与由p型GaN构成的体区26之间的界面30a处产生二维空穴气2DHG。势垒区30与体区26之间的界面30a从漂移区28至源电极14连续地延伸。当对漂移区28施加高电场时，在漂移区28内发生碰撞电离，从而生成空穴、自由电子。生成的空穴、自由电子成为引起下一个碰撞电离的主要原因，若碰撞电离雪崩式的增大，则半导体器件10达到雪崩击穿的状态。然而，在本实施例的半导体器件10中，当在漂移区28内发生碰撞电离时，因碰撞电离生成的空穴通过二维空穴气2DHG迅速地向源电极14排出。由此，碰撞电离的雪崩式增大被抑制，因此半导体器件10的雪崩耐量得到提高。图3中的多个箭头H作为参考示意性地表示空穴的流动。
不限于势垒区30由AlN构成的情形，只要势垒区30由AlxGa(1-X)N(0＜x≤1)构成，上述二维空穴气2DHG就会同样地产生。即，只要势垒区30由AlxGa(1-X)N(0＜x≤1)构成，则半导体器件10的雪崩耐量得到提高。
此外，如图3所示，在本实施例的半导体器件10中，在由AlN构成的势垒区30与由n型GaN构成的漂移区28之间的界面30b处产生二维电子气2DEG。在二维电子气2DEG中，电子迁移率至少比漂移区28高。因此，当半导体器件10的MOSFET被接通并且电子从源电极14经由漂移区28向漏电极16流动时，在漂移区28中发生的能量损失减少。因此，半导体器件10的导通电阻减少，并且半导体衬底12中的发热量也减少。
不限于势垒区30由AlN构成的情形，只要势垒区30由AlxGa(1-X)N(0＜x≤1)构成，上述二维电子气2DEG就会同样地产生。即，只要势垒区30由AlxGa(1-X)N(0＜x≤1)构成，则半导体器件10的导通电阻减少，并且半导体衬底12中的发热量也减少。

Claims (4)

1.一种半导体器件，具备：
半导体衬底，所述半导体衬底包含氮化物半导体；
源电极及漏电极，所述源电极及漏电极分别设置于所述半导体衬底上；以及
栅电极，所述栅电极隔着栅极绝缘膜设置于所述半导体衬底上，
所述半导体衬底具有由GaN构成的第一部分以及由AlxGa(1-X)N(0＜x≤1)构成的第二部分，
所述第一部分具有：
n型源区，所述n型源区与所述源电极接触；
n型漏区，所述n型漏区与所述漏电极接触；
p型体区，所述p型体区介于所述源区与所述漏区之间并且与所述源电极接触；以及
n型漂移区，所述n型漂移区介于所述体区与所述漏区之间并且载流子浓度低于所述漏区，
所述第二部分具有势垒区，所述势垒区与所述源电极、所述体区以及所述漂移区分别接触。
2.根据权利要求1所述的半导体器件，其中，所述AlxGa(1-X)N为AlN。
3.根据权利要求1或2所述的半导体器件，其中，
所述半导体衬底具有第一表面，所述源区、所述体区以及所述漂移区分别在所述第一表面处露出，
所述栅电极隔着所述栅极绝缘膜面向所述第一表面上的在所述源区与所述漂移区之间扩展的所述体区。
4.根据权利要求3所述的半导体器件，其中，
所述半导体衬底进一步具有第二表面，所述第二表面位于所述第一表面的相反侧，并且所述漏区在所述第二表面处露出，
所述源电极设置于所述第一表面上，所述漏电极设置于所述第二表面上。
CN201810123384.4A 2017-02-15 2018-02-07 氮化物半导体器件 Withdrawn CN108470767A (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2017026148A JP6626021B2 (ja) 2017-02-15 2017-02-15 窒化物半導体装置
JP2017-026148 2017-02-15

Publications (1)

Publication Number Publication Date
CN108470767A true CN108470767A (zh) 2018-08-31

Family

ID=63105886

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201810123384.4A Withdrawn CN108470767A (zh) 2017-02-15 2018-02-07 氮化物半导体器件

Country Status (3)

Country Link
US (1) US10326012B2 (zh)
JP (1) JP6626021B2 (zh)
CN (1) CN108470767A (zh)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109671768A (zh) * 2018-12-25 2019-04-23 电子科技大学 一种低结温高耐压的GaN异质结场效应晶体管
CN111129139A (zh) * 2018-11-01 2020-05-08 西安电子科技大学 一种基于悬浮场板的自对准栅氮化镓增强型垂直功率器件

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6988261B2 (ja) * 2017-08-23 2022-01-05 株式会社デンソー 窒化物半導体装置
JP7150269B2 (ja) * 2018-05-09 2022-10-11 学校法人法政大学 窒化ガリウム積層基板および半導体装置
US11139394B2 (en) * 2019-08-30 2021-10-05 Semiconductor Components Industries, Llc Silicon carbide field-effect transistors
DE102020004758A1 (de) * 2019-08-30 2021-03-04 Semiconductor Components Industries, Llc Siliciumcarbid-feldeffekttransistoren
JP7380236B2 (ja) * 2020-01-16 2023-11-15 株式会社デンソー 半導体装置

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001230410A (ja) * 2000-02-18 2001-08-24 Furukawa Electric Co Ltd:The ＧａＮ系電界効果トランジスタとその製造方法
JP2009099601A (ja) * 2007-10-12 2009-05-07 Rohm Co Ltd 窒化物半導体素子
US20090267078A1 (en) * 2008-04-23 2009-10-29 Transphorm Inc. Enhancement Mode III-N HEMTs
US20090278197A1 (en) * 2006-08-24 2009-11-12 Rohm Co., Ltd Mis field effect transistor and method for manufacturing the same
JP2012054324A (ja) * 2010-08-31 2012-03-15 Advanced Power Device Research Association 窒化物系半導体装置
JP2014017291A (ja) * 2012-07-06 2014-01-30 Sumitomo Electric Ind Ltd 縦型半導体装置およびその製造方法
CN103972292A (zh) * 2013-01-30 2014-08-06 三菱电机株式会社 半导体装置及其制造方法
CN104078504A (zh) * 2013-03-26 2014-10-01 丰田合成株式会社 半导体装置及其制造方法
JP2015126080A (ja) * 2013-12-26 2015-07-06 株式会社豊田中央研究所 半導体装置

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998037584A1 (en) * 1997-02-20 1998-08-27 The Board Of Trustees Of The University Of Illinois Solid state power-control device using group iii nitrides
JP5045441B2 (ja) * 2005-03-03 2012-10-10 富士電機株式会社 半導体装置およびその製造方法
JP2007059636A (ja) 2005-08-25 2007-03-08 Renesas Technology Corp Ｄｍｏｓｆｅｔおよびプレーナ型ｍｏｓｆｅｔ
US8659074B2 (en) * 2007-01-09 2014-02-25 Maxpower Semiconductor, Inc. Semiconductor device
US9882049B2 (en) * 2014-10-06 2018-01-30 Alpha And Omega Semiconductor Incorporated Self-aligned slotted accumulation-mode field effect transistor (AccuFET) structure and method
WO2012026234A1 (ja) * 2010-08-24 2012-03-01 三菱電機株式会社 エピタキシャルウエハ及び半導体装置
JP5902116B2 (ja) * 2013-03-25 2016-04-13 株式会社東芝 半導体装置
US9673314B2 (en) * 2015-07-08 2017-06-06 Vishay-Siliconix Semiconductor device with non-uniform trench oxide layer

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001230410A (ja) * 2000-02-18 2001-08-24 Furukawa Electric Co Ltd:The ＧａＮ系電界効果トランジスタとその製造方法
US20090278197A1 (en) * 2006-08-24 2009-11-12 Rohm Co., Ltd Mis field effect transistor and method for manufacturing the same
JP2009099601A (ja) * 2007-10-12 2009-05-07 Rohm Co Ltd 窒化物半導体素子
US20090267078A1 (en) * 2008-04-23 2009-10-29 Transphorm Inc. Enhancement Mode III-N HEMTs
JP2012054324A (ja) * 2010-08-31 2012-03-15 Advanced Power Device Research Association 窒化物系半導体装置
JP2014017291A (ja) * 2012-07-06 2014-01-30 Sumitomo Electric Ind Ltd 縦型半導体装置およびその製造方法
CN103972292A (zh) * 2013-01-30 2014-08-06 三菱电机株式会社 半导体装置及其制造方法
CN104078504A (zh) * 2013-03-26 2014-10-01 丰田合成株式会社 半导体装置及其制造方法
JP2015126080A (ja) * 2013-12-26 2015-07-06 株式会社豊田中央研究所 半導体装置

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
V.MORAES,H.RIEDL,R.RACHBAUER,S.KOLOZSVARI,M.IKEDA,L.PROCHASKA: "Thermal conductivity and mechanical properties of AlN-based thin films", 《JOURNAL OF APPLIED PHYSICS》 *
黄思霓: "GaN基HEMT热效应与耐压新结构研究", 《优秀硕士学位论文》 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111129139A (zh) * 2018-11-01 2020-05-08 西安电子科技大学 一种基于悬浮场板的自对准栅氮化镓增强型垂直功率器件
CN111129139B (zh) * 2018-11-01 2021-03-30 西安电子科技大学 一种基于悬浮场板的自对准栅氮化镓增强型垂直功率器件
CN109671768A (zh) * 2018-12-25 2019-04-23 电子科技大学 一种低结温高耐压的GaN异质结场效应晶体管
CN109671768B (zh) * 2018-12-25 2021-08-17 电子科技大学 一种低结温高耐压的GaN异质结场效应晶体管

Also Published As

Publication number Publication date
JP6626021B2 (ja) 2019-12-25
JP2018133444A (ja) 2018-08-23
US20180233591A1 (en) 2018-08-16
US10326012B2 (en) 2019-06-18

Similar Documents

Publication Publication Date Title
CN108470767A (zh) 氮化物半导体器件
KR100573720B1 (ko) 전력 반도체소자
JP5526136B2 (ja) 窒化物半導体装置
US8884333B2 (en) Nitride semiconductor device
JP5025108B2 (ja) 窒化物半導体素子
US9472403B2 (en) Power semiconductor switch with plurality of trenches
US8723234B2 (en) Semiconductor device having a diode forming area formed between a field-effect transistor forming area and a source electrode bus wiring or pad
US20130313564A1 (en) Semiconductor device and method for manufacturing same
WO2010021099A1 (ja) 電界効果トランジスタ
KR101922122B1 (ko) 노멀리 오프 고전자이동도 트랜지스터
JP2006351691A (ja) 半導体装置
US10083957B2 (en) Semiconductor device
JP2007048866A (ja) 窒化物半導体素子
US11127853B2 (en) Power transistor device including first and second transistor cells having different on-resistances for improved thermal stability
JP2007180143A (ja) 窒化物半導体素子
JP2013069785A (ja) 窒化物半導体装置
US11862629B2 (en) Semiconductor device
US8686436B2 (en) Silicon carbide semiconductor device
KR101927409B1 (ko) 고전자이동도 트랜지스터
JP2007027440A (ja) 半導体装置
TW201635474A (zh) 半導體裝置
JPWO2019077877A1 (ja) 炭化珪素半導体装置および炭化珪素半導体装置の製造方法
JP6651801B2 (ja) 半導体装置および半導体装置の製造方法
WO2014174863A1 (ja) 電界効果トランジスタ
JP4876418B2 (ja) 半導体装置

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
WW01 Invention patent application withdrawn after publication
WW01 Invention patent application withdrawn after publication

Application publication date: 20180831