SiGe spike mono emitter HBT modelling with Hicum€¦ · HICUM workshop Bordeaux June 2011 5/14...

HICUM workshop Bordeaux June 2011 1/14

SiGe spike mono emitter HBT modelling with Hicum

A. Bhattacharyya, C. Maneux, S. Frégonèse, T. Zimmer

IMS - University Bordeaux 1, France


Outline

Introduction: SiGe spike emitter

Basic principle

structure

Device simulation on SiGe spike transistor

Static characteristics

Dynamic characteristics

Compact modeling results

modeling with HICUML2V24

HICUM with an additional base current

Formulation of the model

Modeling results

Conclusion



Basic principle:

From Choi IEEE EDL 2007

Inserting SiGe Spike

inside mono emitter

Increases hole recombination Increases base current


SiGe spike emitter is constructed with the help of IMEC device.


SiGe spike mono-emitter mono-emitter

SiGe Spike

-0.10 -0.05 0.00 0.05 0.10

0.00

0.05

0.10

0.15

0.20

0.25

Ge

_c

on

ten

t(%

)

X(µm)

mono_emitter

SiGe_spike_emitter

x x

SIGe spike mono emitter device

X_mole fraction in both transistors



Device is simulated with calibrated parameter file and applying additional recombinatio for SiGe spike

-0.05 -0.04 -0.03 -0.02 -0.01 0.001E15

1E16

1E17

1E18

1E19

1E20

h_

de

ns

ity

(cm

-3)

X (µm)

mono_emitter

SiGe_spike

-0.08 -0.06 -0.04 -0.02 0.00 0.02 0.04 0.06 0.08 0.10

-2.0

-1.8

-1.6

-1.4

-1.2

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

Ba

nd

_e

ne

rgy

[e

V]

X [µm]

VBE= 0V

VBE= 0.9V

Energy band diagram comparing

SiGe spike emitter and mono emitter

h carrier density at VBE= 0.9V

h carrier density slope increses

near BE junction.



DC and AC Simulaton results with SiGe spike emitter are compared with the mono

emitter

0.4 0.5 0.6 0.7 0.8 0.9 1.0

1x10-11

1x10-10

1x10-9

1x10-8

1x10-7

1x10-6

1x10-5

1x10-4

1x10-3

1x10-2

Ic,

Ib [

A]

VBE

[V]

TCAD_monoEmitter

TCAD_SiGe_Spike

Base current increase

Gummel plot at VCB= 0V fT vs Ic plot at different VCE

10-4

10-3

10-2

0

50

100

150

200

250

300

fT [

GH

z]

Ic [amp]

SiGe_spike_Ft

monoEmitter_Ft

fT identical



7 20 55 148

-3.0

-2.8

-2.6

-2.4

-2.2

-2.0

-1.8

-1.6

-1.4

-1.2

-1.0

Ph

as

e(h

.m.2

1)

Frequency [GHz]

SiGe_Spike

MonoEmitter

VBE

7 20 55 1480.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

VBE

Ph

as

e(Y

.m.1

1)

Frequency [GHz]

SiGe_Spike

MonoEmitter

Excess recombination charge affects the phase of dynamic parameters at low

frequency

Phase of h21 at VCE= 0.5V and

VBE= 0.75V, 0.79V, 0.83V, 0.87V

Phase of Y11 at VCE= 0.5V and

VBE= 0.75V, 0.79V, 0.83V, 0.87V


Compact modeling on SiGe spike transistor

0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1

1E-20

1E-19

Ib/e

xp

(VB

E/V

T)

VBE

[V]

TCAD_SiGe_spike

HICUM_L2V24

SiGe spike mono emitter device simulation data are exported to ICCAP to perform

compact modeling with HICUML2

Gummel plot at VCB= 0V

vb [E+0]

ic.

s ic

.m i

b.m

ib.

s [L

OG

]

0.4 0.6 0.8 1.0 1.21E-12

1E-11

1E-10

1E-9

1E-8

1E-7

1E-6

1E-5

1E-4

1E-3

1E-2

1E-1

Ib/exp(VBE/VT) at VCB= 0V

Base current is not perfect with the existing HICUM


Compact modeling on SiGe spike transistor

7 20 55 148-3.2

-3.0

-2.8

-2.6

-2.4

-2.2

-2.0

-1.8

-1.6

-1.4

-1.2

-1.0

VBE

Ph

as

e(h

.m.2

1)

Frequency [GHz]

TCAD

HICUM_L2V24

7 20 55 1480.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

VBE

Ph

ase

(Y.1

1)

Frequency [GHz]

TCAD

HICUML2V24

Modeling results of phase of h21 and Y11 also show some inconsistency at low frequency


VBE= 0.75V, 0.79V, 0.83V, 0.87V


VBE= 0.75V, 0.79V, 0.83V, 0.87V

Additional recombination parameter necessary to model the phase


HICUM with an additional base current: formulation

Bf

Bhrec

bhrec

QI

1

Tf

Ef EffE

iQ

g

Ef

Berec

berec

QI

' ' ' 'exp 1 exp 1B E B EjBEi BEiS REiS Bhrec

BEi T REi T

V Vi i i I

m V m V

Recombination current due to Ge drop in BC junction

0f f Ef Bf CfQ Q Q Q Q

Where,

Base current components in HICUML2

Introducing an additional recombination current due to the excess hole charge

New model parameter

model parameter


Modeling results with the extended model,

HICUM with an additional base current: modeling results

0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1

1E-20

1E-19

Ib/e

xp

(VB

E/V

T)

VBE

[V]

TCAD

HICUM_L2V24

Extended_HICUM

Ib/exp(VBE/VT) at VCB= 0V

vb [E+0] SiG

e_

spik

e_

ic i

c.s

SiG

e_

spik

e_

ib i

b.s

[L

OG

]

0.4 0.6 0.8 1.0 1.21E-12

1E-11

1E-10

1E-9

1E-8

1E-7

1E-6

1E-5

1E-4

1E-3

1E-2

1E-1

Gummel plot at VCB= 0V

Base current is perfect with the extended model


Modeling results with the extended model,

HICUM with an additional base current: modeling results

7 20 55 148-3.2

-3.0

-2.8

-2.6

-2.4

-2.2

-2.0

-1.8

-1.6

-1.4

-1.2

-1.0

VBE

Ph

as

e(h

.m.2

1)

Frequency(GHz)

TCAD_SiGe_spike

Extended_HICUM

HICUM_L2V24

7 20 55 1480.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

VBE

Ph

as

e(Y

.11

)

Frequency [GHz]

TCAD_SiGe_Spike

Extended_HICUM

HICUM_LV24


VBE= 0.75V, 0.79V, 0.83V, 0.87V


VBE= 0.75V, 0.79V, 0.83V, 0.87V

Excess phase shift is modeled perfectly with the extended model


Conclusion

A SiGe spike mono emitter device is considered for physical devicesimulation (TCAD).

TCAD simulations show an increase in base current without affecting thetransit frequency.

Simulated results are modeled with HICUML2V24 model.

A small extension of HICUM with an additional recombination current isformulated.

Base current and Y11, h21 phase are accurately modeled with the new model.


Acknowledgment

This work is part of the:

• DOTFIVE project supported by the European Commission through the Seventh

Framework Programme for Research and Technological Development.

Acknowledgements also to the MEDEA+ “SIAM” project.

We want to thank Arturo.Sibaja-Hernandez from IMEC for fruitful discussions andprocess information supply.

SiGe spike mono emitter HBT modelling with Hicum€¦ · HICUM workshop Bordeaux June 2011 5/14...

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Transcript of SiGe spike mono emitter HBT modelling with Hicum€¦ · HICUM workshop Bordeaux June 2011 5/14...