compactmodellingofhvmosfets -...

© M. Bucher MOS-‐AK, 11-‐12 April 2013, TU Munich 1

MOS-‐AK Mee;ng, Technical University of Munich Munich, April 11-‐12, 2013

Compact Modelling of HVMOSFETs

MaKhias Bucher12, Nikos Mavredakis1 Antonios Bazigos2, François Krummenacher2, Jean-‐Michel Sallese2

1Technical University of Crete 2École Polytechnique Fédérale de Lausanne

COMON project – HVMOS modelling WG

●  Development / Implementa;on of a full compact model for High-‐Voltage MOSFET

●  Key partners ○  EPFL: EPFL-‐HV MOSFET compact model

○  ams: technology supplier/model user

○  TUC: 1/f noise model development

○  AdMOS: 1/f noise measurement equipment

○  Dolphin Integra;on: Verilog-‐A code compiler, simulator vendor (SMASH)


COMON project – HVMOS publica;ons ●  Modelling of the dria region of the HVMOSFET

○  A. Bazigos, F. Krummenacher, J.-‐M. Sallese, M. Bucher, E. Seebacher, W. Posch, K. Molnar, M. Tang, “A Physics-‐Based Analy1cal Compact Model for the Dri; Region of the HV-‐MOSFET”, IEEE Trans. on Electron Devices, Vol. 58, N° 6, pp. 1710-‐1721, June 2011.

●  RF modelling of the HVMOSFET

○  A. Bazigos, F. Krummenacher, J.-‐M. Sallese, M. Bucher, E. Seebacher, W. Posch, K. Molnar, M. Tang, “RF Compact Modeling of High-‐voltage MOSFETs”, IETE Journal of Research, Vol. 58, N° 3, p. 214-‐221, May-‐June 2012.

●  1/f noise modelling of the HVMOSFET

○  N. Mavredakis, M. Bucher, R. Friedrich, A. Bazigos, F. Krummenacher, J.-‐M. Sallese, T. Gnei;ng, W. Pflanzl, E. Seebacher, “Measurement and Compact Modeling of 1/f Noise in HV-‐MOSFETs“, IEEE Trans. Electron Devices, Vol. 60, N° 2, pp. 670-‐676, Feb. 2013.


Outline

●  Development of an HV-‐MOS compact model o  Dria region accoun;ng for velocity satura;on

o  TCAD verifica;ons

●  Extensions for RF

●  Extensions for 1/f noise o  Verified the model against measurements on many HVMOS technologies from ams


high-‐voltage part dria region

n

low-‐voltage part inner MOS p

© M. Bucher MOS-‐AK, 11-‐12 April 2013, TU Munich

●  HV-‐MOS: 2 parts ○  Connec;ng point: ‘K’ ○  Doping changes type ○  Between channel and dria

●  Low-‐voltage part [1] ○  inner MOSFET

●  inner drain is ‘K’

●  High-‐voltage part [2] ○  Dria region

● A physics-‐based model

Substrate

Source

Gate Drain K

HV-‐MOS macromodel

LDMOS TCAD: 2D doping profile

[1] Y. Chauhan, F. Krummenacher, R. Gillon, B. Bakeroot, M. Declercq, and A. Ionescu, “Compact Modeling of Lateral Nonuniform Doping in High-‐Voltage MOSFETs,” IEEE Trans. Electron Devices, vol. 54, No. 6, pp. 1527–1539, June 2007.

[2] A. Bazigos, F. Krummenacher, J.-‐M. Sallese, M. Bucher, E. Seebacher, W. Posch, K. Molnár and M. Tang, “A physics-‐based analy1cal compact model for the Dri; region of the HV-‐MOSFET” IEEE Trans. Electron Devices, Vol. 58, No. 6, pp. 1710-‐1721, June 2011.

Typical structure of HV-‐MOS

5


●  HV-‐MOS: 2D problem ○  Split into 2 axes

○  x-‐axis: inner MOS ●  Source to ‘K’

○  y-‐axis: DRIFT region ●  ‘K’ to Drain

●  Simplified HV-‐MOS: two 1D problems ○  Solu;on possible

high-‐voltage part dria region

low-‐voltage part inner MOS

From “1×2D” to “2×1D”

6

© M. Bucher 3

MOS-‐AK, 11-‐12 April 2013, TU Munich

Model vs. TCAD simula;ons: ID vs. VG

Device: LDMOS L = 500nm W = 1um Tox = 15nm VDS = {0.1, 1.0, 5.0, 70.0}V VSB = 0V

7


Model vs. TCAD simula;ons: ID vs. VD

Device: LDMOS L = 500nm W = 1um Tox = 15nm VGS = {1.0, 2.0, 5.0}V VSB = 0V

8


DC measurements: ID vs. VG,VDS=0.1V

Device: LDMOS L = 400nm W = 40um Tox = 15nm VDS = 100mV VSB = {0.0, 0.4, 0.8, 1.2, 1.6}V

9


DC measurements: ID vs. VG,VDS=35V

Device: LDMOS L = 400nm W = 40um Tox = 15nm VDS = 35V VSB = {0.0, 0.4, 0.8, 1.2, 1.6}V

10


DC measurements: ID vs. VD

Device: LDMOS L = 400nm W = 40um Tox = 15nm VGS = {1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5}V VSB = 0.0V

11

Dynamic MacroModel Extrinsic parasi;cs


Scalable Gate Resistance

Scalable, Bias-‐Independent Overlap Capacitances

Asymmetrical Junc;on Diodes

RF measurements Y-‐Parameters, real / imaginary part


Device: LDMOS L = 500nm W = 40um Tox = 15nm VDS = {0.0, 30.0}V VSB = 0.0V F = 1.2GHz

A. Bazigos, F. Krummenacher, J.-‐M. Sallese, M. Bucher, E. Seebacher, W. Posch, K. Molnar, M. Tang, “RF Compact Modeling of High-‐Voltage MOSFETs”, IETE Journal of Research, Volume 58, Nr. 3, pp. 214-‐221, 2012.

RF parameter extrac;on


Device: LDMOS L = 500nm W = 40um Tox = 15nm VDS = {0.0, 30.0}V VSB = 0.0V F = 1.2GHz

11G 2

11

Re(Y )RIm(Y )

=

RG on/off

11GG

Im(Y )C2 f

=π

12GD

Im(Y )C2 f

=π

21DG

Im(Y )C2 f

=π

22DD

Im(Y )C2 f

=π

●  Low frequency noise under high-‐voltage condi;ons: largely unexplored. Does the dria region contribute to LFN? ○  Usual approach: use LFN models of ‘LV’ part of HVMOSFET models, adapted to LFN data under “LV” condi;ons.

●  Difficulty of measuring LFN under high VDS – no adequate equipment (typically <5V)

●  New measurement setup developed by AdMOS: can measure LFN of HVMOSFETs up to 200V!

1/f noise in HV-‐MOSFETs: what happens??

© M. Bucher 15 MOS-‐AK, 11-‐12 April 2013, TU Munich

○  N. Mavredakis, M. Bucher, R. Friedrich, A. Bazigos, F. Krummenacher, J.-M. Sallese, T. Gneiting, W. Pflanzl, E. Seebacher, “Measurement and Compact Modeling of 1/f Noise in HV-MOSFETs“, IEEE Trans. Electron Devices, Vol. 60, N° 2, pp. 670-676, Feb. 2013.

1/f Noise in HV-‐MOSFETs

•  Noise spectra measured at high VDS = 50V o  long/short, HVNMOS, HVPMOS – 20V, 50V HVMOS devices

•  Noise in LV part is affected by Dria region: e.g. due to quasi-‐satura;on effect changing VK


●  Total LFN is the sum of LV part LFN, plus Dria part LFN

●  Combina;on of Number (ΔΝ) and mobility (Δμ) fluctua;on

Low frequency noise model in HV-‐MOS


2 2 2 2

2 2 2 2

_ _ _

D D D DI I I I

D D D DLV LV DRIFT

S S S S

I I I Iµ

Δ Δ Δ Δ

ΔΝ Δ ΔΝ

= + +

○  N. Mavredakis, M. Bucher, R. Friedrich, A. Bazigos, F. Krummenacher, J.-M. Sallese, T. Gneiting, W. Pflanzl, E. Seebacher, “Measurement and Compact Modeling of 1/f Noise in HV-MOSFETs“, IEEE Trans. Electron Devices, Vol. 60, N° 2, pp. 670-676, Feb. 2013.

Due to LV channel (ΔN and Δµ) Due to Drift region (ΔN)

Low frequency noise model for HV-‐MOS


( )( )

24

2 2 2

_

2

220

0.51 2ln2 1 21 0.5

2

DI t

D oxLV

Cs d c

d c

Cd s kC s k k d c

S q NI kTWLn C f

q iii q qq q q i

λλ

λ

λ

λαµ αµ

λλ

Δ

ΔΝ

=

⎡ ⎤⎛ ⎞+ −⎢ ⎥⎜ ⎟ ⎛ ⎞+ +⎢ ⎥⎜ ⎟ ⎜ ⎟+ + ⎝ ⎠+ −⎢ ⎥⎜ ⎟+ −⎢ ⎥⎝ ⎠⎣ ⎦

( ) ( )2 2

0 0,

1 ( ) c

s s k kd c d d c

c s k

q q q qi i i

q qλ λ λλ =

+ − += =

+ −

( )2 T

CCN eff clm

UE L L

λ =−Δ

Carrier Number Fluctuations (LV)

( ) ( )( )

2

2

_

ln /1 1

2DI s kH

s kD ox s kLV

S q qk na q qI WLC f q q

µ

Δ

Δ

⎡ ⎤Τ= + + +⎢ ⎥

−⎣ ⎦Mobility

Fluctuations (LV)

(Dependent on qs, qk)

( )2

4_

2 2

_

1 ln 1 22

DI t DRIFTk

D OVD ox driftN DRIFT

S q Nq

I kTWL C f iλΔ

Δ

= ⋅ +

(Dependent only on qk)

Carrier Number Fluctuations (Drift)

1/f Noise in HV-‐MOS vs. bias – long channel

1/f noise vs. ID for 50V HVNMOS.

W=40um, L=10um.

VDS = 50mV, 50V.


SΔVG SΔID

G

S B

D

S B

D

G

SΔID = gm2 SΔVG

1/f Noise in HV-‐MOS vs. bias – short channel

1/f noise vs. ID for 50V HVNMOS.

W=40um, L=0.5um.

VDS = 50mV, 20V, 50V.

Single model @all geometries, bias.

Comparable results for HVPMOS. © M. Bucher MOS-‐AK, 11-‐12 April 2013, TU Munich 20

LFN model vs. bias and geometry


40um

/0.5

um

HV

NM

OS

(50V

)

40u

m/1

0um

40um/10um

HV

PM

OS

(50V) 40um

/1um

Analysis of different LFN contribu;ons •  Different contribu;ons to LFN.

•  Dominant LV channel noise:

o  ΔN at high VG, for short devices (small geometry), and @ high VD (high gm)

o  Δμ @ low VG

•  Dria region LFN becomes significant:

o  For long channel (large geometry channel)...

o  .... and @ low VD, hence the dria region LFN becomes significant w.r.t. the channel noise.


●  A complete HVMOS compact model has been developed. o  Physics-‐based model for the dria region.

o  Combined with a charge-‐model approach for the LV part of the device.

o  Covers all essen;al effects in HVMOS.

●  Extensions for RF have been demonstrated.

●  LFN measurements under high-‐voltage condi;ons. o  Dria region contributes to LFN: par;cularly long-‐channel, low VDS.

o  First complete LFN compact model with contribu;on from dria region.

Conclusions


Thank you for your aKen;on

●  Special thanks to:


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