Performance and Applications of GaN MMICs

Professor Jonathan Scott

&

Professor Anthony Parker

November 2006© THE UNIVERSITY OF WAIKATO • TE WHARE WANANGA O WAIKATO 2

Contents

• “Invited paper” ⇒ license to ramble?

• Contents: Not a memory dump

• You will learn something important• If not, come and see me after, I need to meet you

• There is a single, important take-home…

November 2006© THE UNIVERSITY OF WAIKATO • TE WHARE WANANGA O WAIKATO 3

The History of Active Devices 19

04

1907

1937

Dio

de T

ube

Trio

de T

ube

1stT

V tr

ansm

issi

on

1946

1stre

gula

r br

oadc

ast

1919

1stR

adio

bro

adca

sts

1934

FE

T p

aten

ted

1947

1stB

JT m

ade

(Ger

man

ium

)

1965

Sio

vert

akes

Ge

1961

1stIC

mad

e (G

erm

aniu

m)

1980

GaA

str

ansi

stor

s fa

stes

t

1971

1stIC

mic

ropr

oces

sor

1985

Cra

y-2

Sup

erco

mpu

ter

1990

Ger

man

ium

van

ishe

s

1997

InP

ICs

on s

ale

2000

Gal

lium

-Nitr

ide

FE

Ts

Vacuum age

III-V age

Silicon ageGe

Wide bandgap age

InPGaAs

November 2006© THE UNIVERSITY OF WAIKATO • TE WHARE WANANGA O WAIKATO 4

The History of Active Devices

• Vacuum tube held sway for 50 years

• Easy physics, macro construction, open field

• FET patented mid-way, but not built

• Enabled• Radio communication

• Broadcast entertainment

• Sensitive measurement

• Proportional industrial controlThe time of the radio, tape, long-distance

telephone, radar, TV

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The History of Active Devices

• BJT in Germanium: 1947

• Germanium vanished in 40 years

• Silicon beats Germanium in 1960s

• “Group IV” Motivation:• Robustness

• Size

• Power consumption

• Cost

• Integration The time of the Transistor Radio &

Computer

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The History of Active Devices

• “Group IV” will hold sway for >>50 years

• Why? Bonus of photolithographic manufacture• Integration (matching, cost)

• Scalability

• 1980: LEDs common, GaAs FETs fast

• Motivation:• Faster

• Visible emission

• Integration of passives The time of LEDs, Satellite dishes &

Optical Fiber

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The History of Active Devices

• GaAs FET joined by InP HBT, et al

• “III-V” will hold sway for… only 40 years?

• 2000: GaN FETs appear

• Motivation:• 10x Frequency-x-Power over GaAs

• Thermal >> GaAs

• Breakdown >> Silicon

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Current State of Active Devices

• Rapidity of GaN’s rise…• 50 years for tubes;

• 20 years for IV

• 20 years for III-V (harder chemistry)

• 10 for wide-bandgap

• Why?• Infrastructure courtesy lighting

• Business model courtesy III-V

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History ⇒⇒⇒⇒ Prediction

• Perhaps 20 more years in III-V (GaAs & friends)

• Then Si & WB (GaN?) will dominate

• Why?• RED LEDs boosted GaAs, White LEDs boost GaN even more

• GaN offers so much over GaAs

• Not convinced?

• HDVD to flashlight to garden lights depend on GaN,but GaN was unhead-of 10 years ago

• GaAs took longer, delivered less

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How good is GaN?

Drain-Source Voltage

Dra

in C

urre

nt (

mA

)GaAs Power

MESFET

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GaN was this good… 3 years ago

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Drain Characteristics – 1mm device• Clean characteristics

• Modest dispersion

• Good gm

• Stunning power density

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Powerful and Fast• Broad Ft peak

• This is a GaN-on-Si device• GaN on SiC better

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Robust

• Modest thermal effects

• No trapping (in modulation bandwidth)

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Power-Bandwidth

• Compare broadband amplifier (TWA) performance

• Theory: Ptuned→∞

Actually silicon will not achieve base station performance at 5GHz

AgilentESA

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Power-Bandwidth

• Compare MMIC Technologies

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Applications-Mainline

• A few “No-brainer” applications

• PAs above 2GHz (devices already on sale)

• Radar (old, small-but-price-inelastic market)• Includes TWA replacement

• Sensors (operates at >320C, with only lowered gm)

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Novel Application #1

• MMIC SMPS

• Power conversion with 108 Hz-plus switching speed

• Acknowledged to be beyond silicon

• Some reports so far, but no use of passives yet

• 42V to 12V conversion on-chip?

GaN just moving from devices to

MMICs

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Novel Application #1

• Boost with L in wires

• Buck with L in wires

• Resonant with L on-chip

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Novel Application #2

• Medical diathermy/ablation

• RF heating and thermal ablation commonplace

• Replace “pack+umbilical+probe” with MMIC probe

or

plus

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Novel Application #3

• Dynamic range: Vmax-VNoise

• Tubes good despite noise

• GaN FET noise is low

• High DR DRO• Resonators now good for HV

• Carrier-related noise 10—20dB lower

↑DR↓

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Foundry Offerings

• Indicator of technology maturity?

• Some foundries visible in 2004• DARPA requirement (no real interest)

• Conspicuously unreliable or without foundation (offered!)

• Qinetiq advertised but never returned calls

• 2007: Serious touting at IMS!• IMEC, uGaN, RSC/Teledyne…

GaN foundry club: here we narrow the field to BAE, Cree, Eudyna/Fujitsu, Fraunhofer, HRL, Nitronix, Northrop Grumman, Oki, Raytheon, RF Micro, Rockwell and TriQuint.

From Microwaves101.com(slightly out of date!)

ESA Benchmarks

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Some Publication Statistics

• IEEE IMS (2007)• 26 papers on GaN FET circuits

• 18 on III-V (GaAs/InP HEMT/MESFET/HBT)

• IEEE Trans. Electron Devices & EDL (2006+)• 20% of CS transistor work GaN

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That Single Take Home Fact

• GaN is a major opportunity made for remote countries• Big impact (high value add proposition)

• Wave breaking now (best time to start)

• Foundry model is central (suits the antipodes)