High Temperature Wafer Probing of Power Devices...Power Devices - Applications ... ABB. PowerDevices – Wide Band Gap ... It is mostly related to air pressure value, not to test time

High Temperature Wafer Probing of Power Devices

Masatomo TakahashiACCRETECH

Georg FranzT.I.P.S Messtechnik GmbH

OverviewGeorg Franz

1. Introduction to Power Devices2. Testing Requirements3. Probe Card SolutionMasatomo Takahashi

4. Prober Chuck Improvement5. Experiment: Chuck Thermal Stability6. Conclusion, Follow-On Work

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Power Devices - Applications• Power supplies• Air Condition• Electric Vehicles• Industrial Automation• Trains, Wind Turbines,

Photovoltaic• Power Transmission

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image source: Tsunenobu Kimoto, Japanese Journal of Applied Physics 54, 040103, 2015

Power Devices - Applications in HEV/EV• Rectifiers

Grid AC -> DC charger

• InvertersDC 800V -> AC motor winding

• ConvertersDC 24V -> HV busGenerator -> HV bus

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image source: ST Microelectronics

Power Devices - Types• Si-based devices:– PIN, SBD– IGBT– GTO

• SiC/GaN-based devices:– MOSFET– BJT– JFET

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image source: Littelfuse

image source: ABB

PowerDevices – Wide Band Gap• Silicon Carbide• Gallium Nitride

• Smaller Devices• Higher Efficiency• Less Cooling Effort

• Higher Operating Voltage!• Higher Operating Temperature!

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image source: ST Microelectronics

Test Requirements - Overview• Reverse Voltage (Breakdown Voltage)

-> Up to several kV

• Reverse Voltage (Leakage Current)• Forward Current (On-state resistance)

-> Up to several kA

• UIS – Unclamped Inductive Switching (max power dissipation)

-> Up to several kA / kV

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image source: Wolfspeed,

SiC-MOSFET

image source: ABB, 6.5kV-

600A Si-IGBT

Wafer Test• Current test applications:

– Bare Die– Engineering/Characterization

• Potential test applications:– Tri-Temp Automotive– Move from package to wafer test– Reduce test cost by 50%

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$

High Voltage Wafer Test• Vertical Device• Wafer Bulk on HV• Flash-over risk to

dicing frame!

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C

E G E G

Floating (HV) GND

HV

6 kVDUT2 DUT1

Example: Vertical Device, IGBT (Insulated Gate Bipolar Transistor)

Flash-Over SuppressionApproaches:

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Liquid Inert Gas high breakdown

strength possible

immersion necessary

not useful for wafer test

flushing prober at ambient pressure

pure SF : 3-fold breakdown strengthof ambient air

high cost, greenhouse gas

Pressure linear increase of

breakdown voltage with pressure

works with any gas

compressed air

Flash-Over Suppression - Solution• Air under higher pressure (Paschen)

– whole prober under pressure– whole wafer under pressure– chip-scale chamber– contactless chip-scale chamber

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C

E G E G

Floating (HV) GND

HV

6 kVDUT2 DUT1

Contactless chip scale pressure chamber

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Contactless Seal Operation

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HV-HT Probe Card• Hot compressed

air supply• Dual hot-cold

air streamto protect probe card

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hot compressed air inlet

hot chuck

probe needles

wafer

pressure chamber

gap

PCB moveable Lupo seal ring

cold air flow

hot airflow

150°C

150°C

25°C

High Voltage – High Temperature• Hot air has lower density

-> reduced breakdown strength • Pressure must be increased

to get same breakdown strength• At 125°C -> 36% higher

pressure needed!

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50%

60%

70%

80%

90%

100%

25 75 125 175 225Temperature [°C]

Relative Breakdown Strength

HV-HT Probe Card• production wafer sort• hot wafer chuck 150°C• hot compressed air 150°C• non-contact Lupo seal

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High Temperature Pressurized Air Supply• Electrical heater• Heats cold compressed air to 150°C• closed-loop temperature control• temperature sensor in probe card• fast settling, stable operation• integrated air cooling for probe card

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High temperature testConventional high temperature test condition.

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Chuck Top

Wafer

Blow ambient air

Heater & Temp. Sensor(High temp.)

Probe Card

Chuck (wafer) temperature goes down !

Current issue and improvements

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105

110

115

120

125

130

135

140

145

150

155

0 500 1000 1500 2000 2500 3000 3500 4000

Chuc

k te

mp(

deg)

Time(sec)

Condition: set temp.=150℃/0.5MPa/Die size=2.5㎜/Test time=1000msAir blow start

Probing

Waiting temp. stability

Stronger heater with some sensors

Original heater witha sensor

Original heater with some sensors

High temperature test with Hot air controller

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Prober:UF2000

Hot air controller: LMH150

Probe card: ACTP001-HT

High temperature test enhancementBlow hot air into probe card instead ambient air.

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Chuck Top

Wafer

Blow hot air

Heater & Temp. Sensor(High temp.)

Probe Card

better Temperaturestability

Experiments• Temp. test-1 :

– Chuck temperature stability time after hot air blow start.

• Temp. test-2 : – Chuck temperature variation during probing.

by changing compressed air pressure, Die size, Testing time, etc.

• Flash-over spark test : – With compressed hot air & T.I.P.S. HV demo wafer.

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Temp. test-1– Chuck temperature stability time after air blow start.– Result: Return to chuck set temperature (150℃) within 3min using LMH150

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135

137

139

141

143

145

147

149

151

153

155

0 200 400 600 800 1000 1200Time(sec)

Chuck temperature after air blow

A：High temp air blow Room temp air brow

Air blow start(0.5Mpa)

Approx. 3minStandard probe card (ACTP001) with room temp. air blow.

ACTP001-HT with hot air blow.

Temp. test-2– Chuck temp. during probing with different conditions

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Chuck Temp.(℃)

Pressure(MPa) Chip size（㎜）

Test time（msec）

100 0.3 5.0 300

100 0.5 5.0 1000

150 0.3 5.0 300

150 0.5 5.0 300

150 0.5 5.0 1000

150 0.5 2.5 1000

Temp. test-2– Chuck temp. variation during probing-1– Condition: Set temp.=100℃/0.3MPa/Die size=5㎜/Test time=300ms– Result: Chuck temp. is very stable. (Set temp. ±1℃ during probing)

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85

87

89

91

93

95

97

99

101

103

105

0 200 400 600 800 1000 1200 1400 1600Time(sec)

Chuck temperature during probing

Room temp air brow High temp air blow

Air blow start

Waiting temp. stability Probing

85

87

89

91

93

95

97

99

101

103

105

0 500 1000 1500 2000 2500Tim(sec)

Chuck temperature during probing

Room temp air blow High temp air blow

Temp. test-2– Chuck temp. variation during probing-2– Condition: Set temp.=100℃/0.5MPa/Die size=5㎜/Test time=1000ms– Result: Chuck temp. is very stable. (Set temp. ±1℃ during probing)

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Waiting temp. stability Probing

Air blow start

Temp. test-2– Chuck temp. variation during probing-3– Condition: Set temp.=150℃/0.3MPa/Die size=5㎜/Test time=300ms– Result: Chuck temp. is very stable. (Set temp. ±1℃ during probing)

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135

137

139

141

143

145

147

149

151

153

155

0 200 400 600 800 1000 1200 1400 1600Time(sec)

Chuck temperature during probing

Room temp air blow High temp air blow

Air blow start

Waiting temp. stability Probing

Temp. test-2– Chuck temp. variation during probing-4– Condition: Set temp.=150℃/0.5MPa/Die size=5㎜/Test time=300ms– Result: Chuck temp. is very stable. (Set temp. ±1℃ during probing)

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135

137

139

141

143

145

147

149

151

153

155

0 200 400 600 800 1000 1200 1400 1600

Time(sec)

Chuck temperature during probing

Room temp air blow High temp air blow

Air blow start

Waiting temp. stability Probing

Temp. test-2– Chuck temp. variation during probing-5– Condition: Set temp.=150℃/0.5MPa/Die size=5㎜/Test time=1000ms– Result: Chuck temp. is very stable. (Set temp. ±1℃ during probing)

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135

137

139

141

143

145

147

149

151

153

155

0 500 1000 1500 2000 2500

Chuck temperature during probing

Room temp air blow High temp air blow

Air blow start

Waiting temp. stability Probing

Temp. test-2– Chuck temp. variation during probing-6– Condition: Set temp.=150℃/0.5MPa/Die size=2.5㎜/Test time=1000ms– Result: Chuck temp. is very stable. (Set temp. ±1℃ during probing)

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135

137

139

141

143

145

147

149

151

153

155

0 1000 2000 3000 4000 5000 6000 7000

Chuck temperature during probing

Room temp air blow High tep air blow

Probing

Waiting temp stability

Air blow start

Temp. test-2– Chuck temp. during probing – Test result summary

• Summary:– When using standard probe card with ambient air at 150 ℃, the variation of chuck temp. is +5 to -14℃

max. It is mostly related to air pressure value, not to test time and die size. If using LMH150 with ACTP001-HC, the variation is +/-1℃ under all above conditions.

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Chuck Temp.(℃)

Pressure(Mpa) Chip size（㎜）

Test time（ms） Result

100 0.3 5.0 300 +/-1℃100 0.5 5.0 1000 +/-1℃150 0.3 5.0 300 +/-1℃150 0.5 5.0 300 +/-1℃150 0.5 5.0 1000 +/-1℃150 0.5 2.5 1000 +/-1℃

Flash-Over Spark TestHigh voltage at 100°C

If the test area temp. (inside of Lupo-Ring) is going up, the flash-over voltage is dropped. In case of ACTP001 with ambient air even if chuck temp. is 100℃, the test area temp. must be lower. So the flash-over voltage is just a little bit dropped.

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1

1,5

2

2,5

3

3,5

0 0,1 0,2 0,3 0,4 0,5 0,6

Flas

h-ov

er V

olta

ge (k

V)

Compress Air (MPa)

Flash-over voltage comparison

Drop flash-over voltage approx. 25 %.

Chuck=AmbientCard=ACTP001Air=Ambient

Chuck=100℃Card=ACTP001Air=Ambient

Chuck=100℃Card=ACTP001-HTAir=100℃

Graph1

0.30.30.3

0.40.40.4

0.50.50.5

ambient

100℃

100℃（高温カード）

Compress Air (MPa)

Flash-over Voltage (kV)

Flash-over voltage comparison

2.56

2.44

1.92

2.96

2.82

2.16

3.32

3

2.34

Sheet1

再現が少し悪い サイゲンスコワル

120-137121-137122-137123-137124-137120-137121-137122-137123-137124-137125-137126-137127-137128-137129-137

201808151回目 カイメ0.53.43.333.13.10.222.42.12.12.12.22.32.62.62.7

0.43.22.82.933.10.32.72.42.52.22.72.32.52.52.12.1

0.32.52.82.22.42.70.42.832.833.12.62.832.82.6

0.22.12.42.22.32.40.53.53.43.13.33.23.13.13.33.13

2回目 カイメ0.53.23.33.13.22.90.22.12.42.322.52.222.222

0.42.82.92.92.63.10.32.22.42.72.62.62.42.42.42.32.7

0.32.32.32.32.72.70.43.23.12.92.92.62.92.832.62.9

0.22.22.322.42.20.53.43.33.33.23.23.33.13.33.33.3

500uA

2.2

ウェーハ再クリーニング サイ2.5

20180816120-137121-137122-137123-137124-1373.2

1回目 カイメ222.52.12.22.33.4

0.32.52.62.32.32.7

0.432.92.82.92.6

0.53.33.33.23.13.2

2回目 カイメ0.22.12.52.12.22.4

0.32.52.82.52.62.6

0.42.63.232.82.9

0.53.53.43.23.23.2

20180816120-137121-137122-137123-137124-137AVE

28℃1回目 カイメ0.32.42.62.72.42.72.56

0.42.82.93.12.93.12.96

0.53.43.53.13.13.53.32

2回目 カイメ0.32.72.92.62.42.5

0.42.932.83.13

0.53.43.43.43.43.5

20180816120-137121-137122-137123-137124-137

100℃1回目 カイメ0.32.32.72.12.62.52.44

0.43.12.82.82.92.52.82

0.53.2332.92.93

2回目 カイメ0.3

0.4

0.5

20180817120-137121-137122-137123-137124-137

100℃1回目 カイメ0.32.52.32.12.62.3

42%0.42.92.92.72.82.5

0.53.33333.1

2回目 カイメ0.32.12.42.52.32.6

0.42.832.52.52.9

0.53.43.12.933

20180817120-137121-137122-137123-137124-137

150℃1回目 カイメ0.3

42%0.4

0.5

2回目 カイメ0.3

0.4

0.5

20180817120-137121-137122-137123-137124-137

室温（再） シツオンサイ1回目 カイメ0.32.62.72.62.52.72.62

劣化確認 レッカカクニン0.42.92.62.92.932.86

40%0.53.43.63.13.23.43.34

2回目 カイメ0.32.52.52.62.72.8

0.4333.13.23.3

0.53.53.53.43.43.7

高温カード コウオン

20180820120-137121-137122-137123-137124-137

100℃1回目 カイメ0.321.91.91.91.91.92

0.42.222.12.22.32.16

0.52.32.32.42.32.42.34

2回目 カイメ0.3221.91.91.9

0.42.32.12.22.22.3

0.52.72.42.52.42.5

温度上昇後、厚さ合わせ出来ず。セラミックの反り？

Sheet1

室温（従来カード）

100℃（従来カード）

100℃（高温カード）

気圧（MPa）

スパーク電圧（KV)

高温でのスパーク電圧比較

Sheet2

Sheet3

Flash-Over Spark TestHigh voltage at 100°C

33Takahashi, Franz

Test wafer Check flash-over by camera & monitor.

Conclusion & Follow-On WorkConclusion

– Proven Solution for High-Temperature High- Voltage Wafer Test– Achieved the improvement by chuck design change and using hot air

controller.

Follow-On Work– More field test– Integrate hot air controller into prober– Extend Temperature Range

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Thank you for your attention!

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For questions, please contact:

Masatomo Takahashi

ACCRETECH

[email protected]

+81 426 42 0381

For questions, please contact:

Georg FRANZ

T.I.P.S. Messtechnik GmbH

[email protected]

+43 4242 319 720 19

High Temperature Wafer Probing of Power DevicesOverviewPower Devices - ApplicationsPower Devices - Applications in HEV/EVPower Devices - TypesPowerDevices – Wide Band GapTest Requirements - OverviewWafer TestHigh Voltage Wafer TestFlash-Over SuppressionFlash-Over Suppression - SolutionContactless chip scale pressure chamberContactless Seal OperationHV-HT Probe CardHigh Voltage – High TemperatureHV-HT Probe CardHigh Temperature Pressurized Air SupplyHigh temperature testCurrent issue and improvementsHigh temperature test with Hot air controllerHigh temperature test enhancementExperimentsTemp. test-1Temp. test-2Temp. test-2Temp. test-2Temp. test-2Temp. test-2Temp. test-2Temp. test-2Temp. test-2Flash-Over Spark TestFlash-Over Spark TestConclusion & Follow-On WorkThank you for your attention!