Submicron Scaling of III-V HBTs for 40-200 GHz Analog & Digital ICs

Rodwell et al, UCSB: Keynote talk, 2000 IEEE Bipolar/BICMOS Circuits and Technology Meeting, Minneapolis, September

Submicron Scaling of III-V HBTs for 40-200 GHz Analog & Digital ICs

Mark RodwellUniversity of California, Santa Barbara

[email protected] 805-893-3244, 805-893-3262 fax


State-of-art in HBTs, 2000: cutoff frequencies

Si / SiGe have significantly poorer material parameters …but are much better scaled in size and current density

0 50 100 150 200 250 300 350

Frequency, GHz

SiGe

InP

AlGaAs/GaAs & GaInP/GaAs

ft

fmax

ft

ft

fmax

fmax

~1 um emitters

~1 um emitters(0.4 um)

~0.1 um emitters


State-of-Art in HBTs, 2000: small-scale circuits

0 20 40 60 80 100

Frequency, GHz

A

SiGe

InP

amplifiers

logic

logic

amplifiers

Si / SiGe has rough parity in logic with InP despite lower ft, fmaxdue to higher current density, better emitter contacts

Si/SiGe has significantly slower amplifiers due to lower ft, fmax

Si/SiGe has much better scales of integration, etc


160 Gb/s is more than possible ! UCSB

160 Gb/s LIA simulations using UCSB HBT model

Zach Griffith

PortinNum=1

PortinnNum=2

PortoutnNum=3

PortoutNum=4

V_DCSRC1Vdc=Vee1 V

V_DCSRC2Vdc=Vee2 V

RR3R=Rf Ohm

RR4R=Rf Ohm

SHBT_594_modelX5Area=Area_ inAvia=Avia_ in



SHBT_ 594_modelX8Area=Area_ inAvia=Avia_ in

SHBT_594_modelX2Area=Area_2Avia=Avia_ 2

RR9R=Re1 Ohm

I_P robeI_P robe_ FBn

I_ P robeI_ P robe_CS1

I_P robeI_P_R2n

RR2R=Re2 Ohm

I_P robeI_P robe_CS2

RR8R=Re1 Ohm

I_ P robeI_ P robe_FB

I_P robeI_P_R2

SHBT_594_modelX1Area=Area_2Avia=Avia_2

RR1R=Re2 Ohm

I_P robeI_P robe_ in SHBT_ 594_model

X3Area=Area_1Avia=Avia_ 1

I_P robeI_P robe_ innSHBT_594_model

X4Area=Area_1Avia=Avia_ 1

RR7R=Rcs2 Ohm

RR10R=Rcs1 Ohm

RR11R=Ree Ohm

RR12R=Ree Ohm

RR5R=Rl Ohm

RR6R=Rl Ohm

PortinNum=1

PortinnNum=2

PortoutnNum=3

PortoutNum=4

V_DCSRC1Vdc=Vee1 V

V_DCSRC2Vdc=Vee2 V

RR3R=Rf Ohm

RR4R=Rf Ohm



SHBT_594_ modelX2Area=Area_ 2Avia=Avia_ 2

RR9R=Re1 Ohm

I_ P robeI_ P robe_FBn

I_ P robeI_ P robe_CS1

I_ P robeI_ P_R2n

RR2R=Re2 Ohm

I_P robeI_P robe_ CS2

RR8R=Re1 Ohm

I_ P robeI_ P robe_FB

I_ P robeI_ P_R2

SHBT_594_modelX1Area=Area_ 2Avia=Avia_ 2

RR1R=Re2 Ohm

I_P robeI_P robe_ in SHBT_ 594_model

X3Area=Area_1Avia=Avia_1

I_ ProbeI_ Probe_ innSHBT_594_ model

X4Area=Area_1Avia=Avia_1

RR7R=Rcs2 Ohm

RR11R=Ree Ohm

RR10R=Rcs1 Ohm

RR12R=Ree Ohm

RR5R=Rl Ohm

RR6R=Rl Ohm



0 1 2 3 4 5 6 7 8 9 10 11 12 13

time, psec

-0.22

-0.20

-0.18

-0.16

-0.14

-0.12

-0.10

-0.08

-0.06

-0.04

-0.02

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.20

0.22

out_

diff

0 1 2 3 4 5 6 7 8 9 10 11 12 13

time, psec

-0.22

-0.20

-0.18

-0.16

-0.14

-0.12

-0.10

-0.08

-0.06

-0.04

-0.02

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.20

0.22

out_

diff

AgilentConexant


for x 2 improvement of all parasitics: ft, fmax, logic speed…base 2: 1 thinnercollector 2:1 thinneremitter, collector junctions 4:1 narrowercurrent density 4:1 higheremitter Ohmic 4:1 less resistive

Scaling Laws for fast HBTs

Challenges with Scaling:Collector mesa HBT: collector under base Ohmics. Base Ohmics must be one transfer lengthsets minimum size for collector Emitter Ohmic: hard to improve…how ?Current Density: dissipation, reliabilityLoss of breakdownavalanche Vbr never less than collector Egap (1.12 V for Si, 1.4 V for InP) ….sufficient for logic, insufficient for power

emitterbase contact

collectorcontact

SI substrate

InGaAs subcollector

InP collector

InGaAscollector

InP subcollector

InGaAs baseundercut

collector junction

base contactemitter

base contact

SI substrate

base

sub collector

base contact pad

collectorcontact

polymer polymer

collector-base junction

Narrow-mesa with 1E20 carbon-doped base

undercut-collector

transferred-substrate


Submicron Transferred-Substrate HBT

0

5

10

15

20

25

30

10 100 1000

Gai

ns, d

B

Frequency, GHz

fmax

= 1.1 THzft = 204 GHz

Mason's gain, U

H21

MSG

emitter, 0.4 x 6 mm2

collector, 0.4 x 6 mm2

Ic = 6 mA, V

ce = 1.2 V

UCSBMichelle Lee

3000 Å collector400 Å base with 52 meV gradingAlInAs / GaInAs / GaInAs HBT

(?)


Record ft HBT UCSBYoram Betser

Emitter 1 x 8 mm2, Collector 2 x 8.5 mm2.0

10

20

30

40

50

1 10 102

Gai

ns

(dB

)

Frequency (GHz)

h21

U

VCE

= 1 V, JC = 1.5 mA/um2

fMAX

= 295 GHz

f t = 295 GHz

2000 Å collector300 Å base with 52 meV gradingAlInAs / GaInAs / GaInAs HBT


1E9 1E10 1E11 1E12

freq, Hz

-20

-15

-10

-5

0

5

10

15

20

dB(h

21)

UdB

(sho

rt..S

(2,1

))

m1freq=303.0GHzdB(short..S(2,1))=0.000

m1

m2freq=165.0GHzdB(short..S(2,1))=0.000

m2

0

1

2

3

4

5

6

7

8

0 1 2 3 4 5 6

Ic - V

ce characteristics

I c (mA

)

Vce

(volts)

IB in steps

of 20 uA 105 A/cm2

High Speed, High Breakdown DHBTs

ft = 165 GHz; fmax = 303 GHz

5 V breakdown at 105 A/cm2

UCSBpk SundararajanM Dahlstrom

0

5000

1 104

1.5 104

2 104

0 2 4 6 8 10

J c (A/c

m2 )

Vce

(volts)

BVCEO>9 V

1x 8 micron emitter, 2x 10 micron collector


High Speed Amplifiers

18 dB, DC-50 GHz

UCSBDino Mensa

PK Sundararajan

8.2 dB, DC-80 GHz

-20

-15

-10

-5

0

5

10

15

20

0 10 20 30 40 50

397 GHz gain x bandwidth from 2 HBTs

S22

S11

S21


HBT distributed amplifier UCSBPK Sundararajan11 dB, DC-87 GHz

AFOSR

TWA with internal ft-doubler cells


InP-HBT W-band Amplifiers

Balanced Amplifier: 10.7dBm at 78GHz

(transferred-substrate HBT)

InGaAs-collector: Vbr=1.5 V low power

InP-collector: Vbr~5 V higher powers expected

UCSB AROCaltech

Common-Base Amplifier: 9.7dBm at 82.5 GHz

James Guthrie


66 GHz HBT master-slave flip-flop

Objectives: 100 + GHz logic

Approach: transferred-substrate HBTs, microwave / digital design

Simulations: 95 GHz clock rate in SPICE

Accomplishments:operation to 66 GHz

UCSB

33.0 GHz static divider output at 66.0 GHz input

-100

-80

-60

-40

-20

0

0 50 100 150 200

divi

der o

utpu

t, m

V

time, ps

Michelle Lee


UCSB3500-HBT 20 GHz Sine ROM

(it is hard to build large ICs in a university cleanroom)

input latches

decoder core

receivers & drivers

ROM core

selectors

receivers

output latches

Yoram BetserWOM

IVC

t

Iref

Ik

Low Voltage Swing

Digital Signal

Io

o

k

III

qkTV 0ln


Delta-Sigma ADC18 GHz clock rate 150 HBTs

gm gm

Integrator

clock

(bias)Integrator

output M/SFlip flop

1 bitDAC

1 bitDAC

Input

(bias)

Delayed Clock

ADC BlockDiagram

-120

-100

-80

-60

-40

-20

0

1 10 100 1000 10000

Pow

er S

pect

rum

(dB

bel

ow fu

ll sc

ale)

Frequency (MHz)

InputOutput

OSR = 128F

clock = 20 GHz

SNR = 90 dB in 1 MHz

Matlab Simulation

<-signalADC noise

= 150 dB in 1 Hz

UCSB

6.2 ENOB for a 1 GHz signal( 2 GS/s equivalent Nyquist)

5 5

50 50

6.6K1.25K6.6K

250

1.25K

-4v

5 5

6.6K1.25K6.6K

250

1.25K

clock buffers

RTZ DAC

(transmission linedelay to setDAC gatiing clocktowards later half of the eye )

clock

M/S latched comparatormaster slave

integrator 1

integrator 2

(off-wafer op-amps setscommon-mode bias)

(off-wafer op-amps setscommon-mode bias)

input

clock

delayedclock

Shrinivasan Jaganathan


185 GHz HBT Amplifier UCSBMiguel Urteaga

0.2pF

50 301.2ps

50

300.2ps

801.2ps

0.6ps

801.2ps

50

IN

OUT

140 150 160 170 180 190 200 210 220Frequency, GHz

-5-4-3

-2-101

234

S21,

dB

140 150 160 170 180 190 200 210 220

Frequency, GHz

-18

-16

-14

-12

-10

-8

-6

-4

-2

0

S11,

S22,

dB

S22

S11

AFOSR


19 GHz 2-bit adder UCSBThomas Mathew

C1C1

C1out = A0B0 + B0C0 + A0C0

C1out = A0B0 + B0C0 + A0C0

C1 C1

C1 C1

DIODE LEVEL SHIFTER

C0

B0

C0

B0

B0 B0

C0 C0

A0 A0

CK CK

LOGIC STAGE

C1 C1

B1 B1

C1 C1

B1 B1

A1 A1

CKCK

C2out = A1B1 + B1C1 + A1C1C2out = A1B1 + B1C1 + A1C1

LATCHSTAGE

B0 = B1 = High (0.0V), A0 = A1 = Low (-0.3V), C0 = C2out for testing

-0.3

-0.25

-0.2

-0.15

-0.1

-0.05

0

0 100 200 300 400 500

fmax ck

= 19GHz, fout

= 9 .5GHz

Vou

t(Vol

ts)

Time(ps)

S0 = A0 + B0 + C0

S0 = A0 + B0 + C0

C0 C0

C0

B0 B0

B0

A0 A0

CK CK CKCK

3 INPUT XOR

LATCHSTAGE

LATCH FOR PIPELINE DELAY

C0 = High (0.0V), A0 = Low (-0.3V), B0 = S0 for testing

Documents

Submicron Scaling of III-V HBTs for 40-200 GHz Analog & Digital ICs