1

Recent Power Semiconductor Recent Power Semiconductor Recent Power Semiconductor Recent Power Semiconductor

Devices Technologies forDevices Technologies forDevices Technologies forDevices Technologies for

a Future Smart Societya Future Smart Societya Future Smart Societya Future Smart Society

Prof. Noriyuki Prof. Noriyuki Prof. Noriyuki Prof. Noriyuki IwamuroIwamuroIwamuroIwamuro

Faculty of Pure and Applied SciencesFaculty of Pure and Applied SciencesFaculty of Pure and Applied SciencesFaculty of Pure and Applied SciencesUniversity of TsukubaUniversity of TsukubaUniversity of TsukubaUniversity of Tsukuba

2

Image of Future Smart CityImage of Future Smart CityImage of Future Smart CityImage of Future Smart City

Smart city: Energy saving city for making full use ofSmart city: Energy saving city for making full use ofSmart city: Energy saving city for making full use ofSmart city: Energy saving city for making full use ofadvanced technology such as IT or advanced technology such as IT or advanced technology such as IT or advanced technology such as IT or power devicespower devicespower devicespower devices

3

MotorBattery Inveter

Inverter

DC-Chopper

Engine

Gen. Others

DCDCDCDC

ACACACAC

Power Conversion

from DC to AC

Power Semiconductor DevicesPower Semiconductor DevicesPower Semiconductor DevicesPower Semiconductor Devices

PCUPCUPCUPCU

1200V/400A1200V/400A1200V/400A1200V/400A

Power Semiconductor device in Toyota PriusPower Semiconductor device in Toyota PriusPower Semiconductor device in Toyota PriusPower Semiconductor device in Toyota Prius

4

Gen.Gen.Gen.Gen.

ConverterConverterConverterConverter

Power LinePower LinePower LinePower Line

Power Semiconductor device in Wind turbinePower Semiconductor device in Wind turbinePower Semiconductor device in Wind turbinePower Semiconductor device in Wind turbine

1700V/450A1700V/450A1700V/450A1700V/450A～～～～1000A1000A1000A1000A

Power Semiconductor DevicesPower Semiconductor DevicesPower Semiconductor DevicesPower Semiconductor Devices

（（（（IGBTIGBTIGBTIGBT ModuleModuleModuleModule））））

Power Conversion Power Conversion Power Conversion Power Conversion

from AC to ACfrom AC to ACfrom AC to ACfrom AC to AC

5

Power electronics applicationsPower electronics applicationsPower electronics applicationsPower electronics applications

Air Conditioner

Home Appliance

Robotics

UPS

Train

EV, HEV

Bottom line for the power conversion/power devicesBottom line for the power conversion/power devicesBottom line for the power conversion/power devicesBottom line for the power conversion/power devices

1)Higher efficiency1)Higher efficiency1)Higher efficiency1)Higher efficiency and 2)Higher ruggednessand 2)Higher ruggednessand 2)Higher ruggednessand 2)Higher ruggedness

⇒⇒⇒⇒Superior power devices are strongly requiredSuperior power devices are strongly requiredSuperior power devices are strongly requiredSuperior power devices are strongly required

6

10M

1M

100 k

10k

1k

100

1010 100 1k 10 k 100 k 1M 10M 100 M

SMPSSMPSSMPSSMPS

AudioAudioAudioAudio

Inverter Air conditionerInverter Air conditionerInverter Air conditionerInverter Air conditioner

Home applianceHome applianceHome applianceHome appliance

UPSUPSUPSUPS

PowerlinePowerlinePowerlinePowerline

MOSFET

IGBT MDL

GTO Thyrisitor

RailwayRailwayRailwayRailway

Servo, Servo, Servo, Servo,

RoboticsRoboticsRoboticsRobotics

InverterInverterInverterInverter

AutomotiveAutomotiveAutomotiveAutomotive

Silicon(Si)Silicon(Si)Silicon(Si)Silicon(Si)----MOSFET, SiMOSFET, SiMOSFET, SiMOSFET, Si----IGBT widely acceptedIGBT widely acceptedIGBT widely acceptedIGBT widely accepted

Application Field of Power DevicesApplication Field of Power DevicesApplication Field of Power DevicesApplication Field of Power Devices（（（（2015201520152015））））

Freq

uenc

y(H

z)

Device CapacityDevice CapacityDevice CapacityDevice Capacity (VA)(VA)(VA)(VA)

7

OnOnOnOn----state voltage(On resistance):state voltage(On resistance):state voltage(On resistance):state voltage(On resistance):▲▲▲▲50%, Die size:50%, Die size:50%, Die size:50%, Die size:▲▲▲▲70707070％％％％

2nd Gen.

3rd Gen.

4th Gen.

5th Gen.

6th Gen.

Area=1

A=0.71

A=0.71

A=0.43

A=0.31

1200V/100A

Device

Year

（（（（Courtesy: Fuji ElectricCourtesy: Fuji ElectricCourtesy: Fuji ElectricCourtesy: Fuji Electric））））

On-

stat

e vo

ltag

e(V

)

Improvement of SiImprovement of SiImprovement of SiImprovement of Si----IGBT IGBT IGBT IGBT

8

0000

50505050

100100100100

150150150150

200200200200

250250250250

300300300300

1988198819881988 1990199019901990 1992199219921992 1994199419941994 1996199619961996 1998199819981998 2000200020002000 2002200220022002 2004200420042004

（年）（年）（年）（年）

チップ

厚さ(u

m)

チップ

厚さ(u

m)

チップ

厚さ(u

m)

チップ

厚さ(u

m)

600V

1200V

1700V

After 2003, Improvement of thin wafer slow downAfter 2003, Improvement of thin wafer slow downAfter 2003, Improvement of thin wafer slow downAfter 2003, Improvement of thin wafer slow down

⇒⇒⇒⇒In 2015, thickness is comparable to that in 2003In 2015, thickness is comparable to that in 2003In 2015, thickness is comparable to that in 2003In 2015, thickness is comparable to that in 2003

Breakdown voltage is not sustainable when we thin the wafer moreBreakdown voltage is not sustainable when we thin the wafer moreBreakdown voltage is not sustainable when we thin the wafer moreBreakdown voltage is not sustainable when we thin the wafer more

⇒⇒⇒⇒Si limit!Si limit!Si limit!Si limit!

Limitation of Thin Wafer TechnologyLimitation of Thin Wafer TechnologyLimitation of Thin Wafer TechnologyLimitation of Thin Wafer Technology

(Year)

thic

knes

s

9

Ge・・・・First semiconductor material

・・・・μｅ＝３９００ｅ＝３９００ｅ＝３９００ｅ＝３９００ ｃｍｃｍｃｍｃｍ2/ＶｓＶｓＶｓＶｓ

・・・・μｈ＝１９００ｈ＝１９００ｈ＝１９００ｈ＝１９００ ｃｍｃｍｃｍｃｍ2/Vs

・・・・Eg ＝＝＝＝ ０．６６ｅＶ０．６６ｅＶ０．６６ｅＶ０．６６ｅＶ Operation Temp.４０４０４０４０℃℃℃℃

・・・・Eg ＝＝＝＝ １．１２ｅＶ１．１２ｅＶ１．１２ｅＶ１．１２ｅＶ Operation Temp １５０１５０１５０１５０℃℃℃℃

・・・・All application

・・・・Fast switching

・・・・High Temperature operation

GaAs・・・・Eg ＝＝＝＝ 1.42ｅＶｅＶｅＶｅＶ Operation temperature３５０３５０３５０３５０℃℃℃℃

・・・・LD, LED

・・・・High speed(HEMT, MESFET））））

・・・・complicated process

・・・・difficulty of bipolar device

・・・・No good passivation film

SiC

Si

GaN

Change of semiconductor device materialsChange of semiconductor device materialsChange of semiconductor device materialsChange of semiconductor device materials

Diamond

2015

Wide Band GapWide Band GapWide Band GapWide Band GapMaterialsMaterialsMaterialsMaterials

10

US President B. Obama announcedUS President B. Obama announcedUS President B. Obama announcedUS President B. Obama announced

(Jan. 2014)(Jan. 2014)(Jan. 2014)(Jan. 2014)

“the advanced manufacturing institute“the advanced manufacturing institute“the advanced manufacturing institute“the advanced manufacturing institute

for energyfor energyfor energyfor energy----efficient efficient efficient efficient wide band gap wide band gap wide band gap wide band gap

semiconductorsemiconductorsemiconductorsemiconductor““““

National project of SIPNational project of SIPNational project of SIPNational project of SIP（（（（Strategic Strategic Strategic Strategic

Innovation Promotion Program)launchedInnovation Promotion Program)launchedInnovation Promotion Program)launchedInnovation Promotion Program)launched

for development offor development offor development offor development of wide band gap wide band gap wide band gap wide band gap

semiconductor in 2014 semiconductor in 2014 semiconductor in 2014 semiconductor in 2014

World focusing on the WBG semiconductorsWorld focusing on the WBG semiconductorsWorld focusing on the WBG semiconductorsWorld focusing on the WBG semiconductors

11

Why Wide Band Gap materials? Why Wide Band Gap materials? Why Wide Band Gap materials? Why Wide Band Gap materials?

Advantage of WBGAdvantage of WBGAdvantage of WBGAdvantage of WBG device over Si onedevice over Si onedevice over Si onedevice over Si one

→Wm

= 1/10

→Ron = 1/300

•VB=E

cW

m/2

•ND=εEc２/2qV

B

•R=Wm/qμN

D

SiC DeviceSiC DeviceSiC DeviceSiC Device

・・・・Thinner nThinner nThinner nThinner n---- layer(1/10 of Si)layer(1/10 of Si)layer(1/10 of Si)layer(1/10 of Si)

・・・・High impurity densityHigh impurity densityHigh impurity densityHigh impurity density

→→→→Lower RonALower RonALower RonALower RonA

Also, higher temp. applicableAlso, higher temp. applicableAlso, higher temp. applicableAlso, higher temp. applicable

12

WhyWhyWhyWhy SiCSiCSiCSiC power devices?power devices?power devices?power devices?

１１１１. Limit of Si power devices. Limit of Si power devices. Limit of Si power devices. Limit of Si power devices

２２２２. Requirement from new application field. Requirement from new application field. Requirement from new application field. Requirement from new application field

①①①①High temperature operationHigh temperature operationHigh temperature operationHigh temperature operation（（（（over 200over 200over 200over 200℃℃℃℃））））

②②②②Under very severe environment(Under very severe environment(Under very severe environment(Under very severe environment(ex.Spaceex.Spaceex.Spaceex.Space))))

③③③③SSSSmall and down sizemall and down sizemall and down sizemall and down size

④④④④Higher efficiencyHigher efficiencyHigher efficiencyHigher efficiency

3. History, development achievement3. History, development achievement3. History, development achievement3. History, development achievement

13

Merit for high temp. operationMerit for high temp. operationMerit for high temp. operationMerit for high temp. operation

Hybrid Car（Lexus LS600h） HV Inverter system(PCU)

Less space⇒ Smaller size

Abolition of exclusive cooling system for InverterAbolition of exclusive cooling system for InverterAbolition of exclusive cooling system for InverterAbolition of exclusive cooling system for Inverter

⇒⇒⇒⇒Common use of radiator coolantCommon use of radiator coolantCommon use of radiator coolantCommon use of radiator coolant

Si IGBTSi IGBTSi IGBTSi IGBT InverterInverterInverterInverter SiC MOSFETSiC MOSFETSiC MOSFETSiC MOSFET InverterInverterInverterInverter

Ref. Denso Corp.

14

Fuji Electric started the SiC device mass production in Oct, 2013.Fuji Electric started the SiC device mass production in Oct, 2013.Fuji Electric started the SiC device mass production in Oct, 2013.Fuji Electric started the SiC device mass production in Oct, 2013.

（（（（Matsumoto, Nagano, JapanMatsumoto, Nagano, JapanMatsumoto, Nagano, JapanMatsumoto, Nagano, Japan））））

SiC Power device mass production by SiC Power device mass production by SiC Power device mass production by SiC Power device mass production by ΦΦΦΦ6 wafer6 wafer6 wafer6 wafer

15

SiC power electronics product applicationSiC power electronics product applicationSiC power electronics product applicationSiC power electronics product application

（（（（Produced by Mitsubishi Electric））））

（（（（Ref:Web of Council for Science, Technology and Innovation Ref:Web of Council for Science, Technology and Innovation Ref:Web of Council for Science, Technology and Innovation Ref:Web of Council for Science, Technology and Innovation ））））

SiC InverterSiC InverterSiC InverterSiC Inverter

Application for RailwayApplication for RailwayApplication for RailwayApplication for Railway

SiC Inverter installed in Tokyo Metro Ginza LineSiC Inverter installed in Tokyo Metro Ginza LineSiC Inverter installed in Tokyo Metro Ginza LineSiC Inverter installed in Tokyo Metro Ginza Line

(Si(Si(Si(Si----IGBT+SiCIGBT+SiCIGBT+SiCIGBT+SiC----SBD)SBD)SBD)SBD)

Power loss reduction:Power loss reduction:Power loss reduction:Power loss reduction:▲▲▲▲40%40%40%40%

16

MEGA Solar PCS which 1200V All SiCMEGA Solar PCS which 1200V All SiCMEGA Solar PCS which 1200V All SiCMEGA Solar PCS which 1200V All SiC----MOSFET module is installed.MOSFET module is installed.MOSFET module is installed.MOSFET module is installed.

(Fuji Electric, May. 2014(Fuji Electric, May. 2014(Fuji Electric, May. 2014(Fuji Electric, May. 2014））））

Features:

Higher efficiency and small size

・Efficiency 98.8%

・Volume ▲20％ reduction

(SiC(SiC(SiC(SiC----MOSFET+SiCMOSFET+SiCMOSFET+SiCMOSFET+SiC----SBD)SBD)SBD)SBD)

(Ref. Web of Nikkei Technology On(Ref. Web of Nikkei Technology On(Ref. Web of Nikkei Technology On(Ref. Web of Nikkei Technology On----line)line)line)line)

Also, Toyota announced the SiC power devices Also, Toyota announced the SiC power devices Also, Toyota announced the SiC power devices Also, Toyota announced the SiC power devices

will be installed in the new HEV in 2020.will be installed in the new HEV in 2020.will be installed in the new HEV in 2020.will be installed in the new HEV in 2020.

SiC power electronics product applicationSiC power electronics product applicationSiC power electronics product applicationSiC power electronics product application

17

Issues to be solved in SiCIssues to be solved in SiCIssues to be solved in SiCIssues to be solved in SiC

(M.Firuhashi et al（Mitsubishi）, ISPSD2013, pp.55）

Measured results of the Vth shift Measured results of the Vth shift Measured results of the Vth shift Measured results of the Vth shift

after applying Vg=+20V, 1000hrs @125after applying Vg=+20V, 1000hrs @125after applying Vg=+20V, 1000hrs @125after applying Vg=+20V, 1000hrs @125℃℃℃℃

1. Threshold instability after applying Vg

2. Improvement of on-state resistance

Vth shift is still observedVth shift is still observedVth shift is still observedVth shift is still observed

1111

10101010

100100100100

1000100010001000

100100100100 1000100010001000 10000100001000010000

Breakdown Voltage（（（（V））））

Ron

A(m

Ωcm

2 )

Comparison of VbrComparison of VbrComparison of VbrComparison of Vbr----RonA RonA RonA RonA

in various power devices @25in various power devices @25in various power devices @25in various power devices @25℃℃℃℃

RonA: Large difference betweenRonA: Large difference betweenRonA: Large difference betweenRonA: Large difference between

measured data and the theoretical limitmeasured data and the theoretical limitmeasured data and the theoretical limitmeasured data and the theoretical limit

0.2~0.3V0.2~0.3V0.2~0.3V0.2~0.3V

18

E C

E i

E FM

E V

interface

Acceptor

E FS

x d

qV G

qV s

qV f

electrons

---

n-

p+

Source

Gate -----SiO2

SiCGate Electrode

Negative charged trappedat the interface states

Influence of interface states on MOSFETInfluence of interface states on MOSFETInfluence of interface states on MOSFETInfluence of interface states on MOSFET

(a)Energy band diagram (b)Cross section of MOSFET

Electron trapped at the interface states⇒electrons scattered⇒①μmos degrades②Vth increase

p

19

(Ref. Web of Yaskawa Electric)(Ref. Web of Yaskawa Electric)(Ref. Web of Yaskawa Electric)(Ref. Web of Yaskawa Electric)

Solar PCS (4.5kWSolar PCS (4.5kWSolar PCS (4.5kWSolar PCS (4.5kW）））） Features:

Higher efficiency and small size

・Efficiency 98.%

・Volume ▲50％ reduction

・Low noise

GaN power electronics product applicationGaN power electronics product applicationGaN power electronics product applicationGaN power electronics product application

Solar PCS(4.5kW) in which 600V GaN-HEMT devices are installed.

（Yaskawa Electric, Dec. 2014）

20

GaNGaNGaNGaN----HEMT DevicesHEMT DevicesHEMT DevicesHEMT Devices（（（（IEDM2014IEDM2014IEDM2014IEDM2014））））

Device structureDevice structureDevice structureDevice structure

GaN on Si HEMT+SiGaN on Si HEMT+SiGaN on Si HEMT+SiGaN on Si HEMT+Si----MOS CascodeMOS CascodeMOS CascodeMOS Cascode

WaferWaferWaferWafer

Φ6GaN on Si HEMTΦ6GaN on Si HEMTΦ6GaN on Si HEMTΦ6GaN on Si HEMT

21

Classification of SiC and GaN devicesClassification of SiC and GaN devicesClassification of SiC and GaN devicesClassification of SiC and GaN devices

For high power device, vertical structure is suitableFor high power device, vertical structure is suitableFor high power device, vertical structure is suitableFor high power device, vertical structure is suitable

⇒⇒⇒⇒SiC: High power, GaN: Low/Medium power SiC: High power, GaN: Low/Medium power SiC: High power, GaN: Low/Medium power SiC: High power, GaN: Low/Medium power

SiC: Vertical DeviceSiC: Vertical DeviceSiC: Vertical DeviceSiC: Vertical Device

Current flows in the whole regionCurrent flows in the whole regionCurrent flows in the whole regionCurrent flows in the whole region

→High current →High current →High current →High current

GaN: Lateral DeviceGaN: Lateral DeviceGaN: Lateral DeviceGaN: Lateral Device

Current flows at the surfaceCurrent flows at the surfaceCurrent flows at the surfaceCurrent flows at the surface

→Low current→Low current→Low current→Low current

Electrode

Ｓｕｂ．（Ｓｉ）

Ｂｕｆｆｅｒ（High resistance)

ＧａＮ

Electrode ElectrodeCurrent flow

Current flow

SiC substrate

SiC EPI

Electrode

No good GaN wafer applicableNo good GaN wafer applicableNo good GaN wafer applicableNo good GaN wafer applicable

⇒⇒⇒⇒GaN on Si structureGaN on Si structureGaN on Si structureGaN on Si structure

GoodGoodGoodGood SiC wafer applicableSiC wafer applicableSiC wafer applicableSiC wafer applicable

⇒⇒⇒⇒SiC on SiC structureSiC on SiC structureSiC on SiC structureSiC on SiC structure

22

SummarySummarySummarySummary

１１１１. Present Status of Power Semiconductor Devices. Present Status of Power Semiconductor Devices. Present Status of Power Semiconductor Devices. Present Status of Power Semiconductor Devices

2. Recent Progress of SiC Power Devices2. Recent Progress of SiC Power Devices2. Recent Progress of SiC Power Devices2. Recent Progress of SiC Power Devices

SiCSiCSiCSiC----MOSFET Module application just started forMOSFET Module application just started forMOSFET Module application just started forMOSFET Module application just started for

high power applicationhigh power applicationhigh power applicationhigh power application

3. Recent Progress of GaN Power Devices3. Recent Progress of GaN Power Devices3. Recent Progress of GaN Power Devices3. Recent Progress of GaN Power Devices

GaNGaNGaNGaN----HEMT application just started forHEMT application just started forHEMT application just started forHEMT application just started for

low/medium power applicationlow/medium power applicationlow/medium power applicationlow/medium power application

23

Thank you for your kind attentionThank you for your kind attentionThank you for your kind attentionThank you for your kind attention