Full –Band Particle-Based Analysis of Full –Band Particle-Based Analysis of Device Scaling For 3D Tri-gate FETsDevice Scaling For 3D Tri-gate FETs

ByBy

P. ChineyP. Chiney

Electrical and Computer Engineering Department, Electrical and Computer Engineering Department, Illinois Institute of Technology, Chicago, IL 60616Illinois Institute of Technology, Chicago, IL 60616

M. Saraniti , J. Branlard, Illinois Institute of Technology, Chicago, IL 60616 S. Aboud, Worcester Polytechnic Institute, Worcester, MA 01609-2280

S. Goodnick, Arizona State University, Tempe, AZ 85287

Full-band Particle-based Analysis of Device Scaling For 3D Tri-gate FETs

OutlineOutline

I.I. Full-band Particle-based MethodFull-band Particle-based Method

II.II. The Tri-gate devicesThe Tri-gate devices

III.III. Device SimulationDevice Simulation

IV.IV. Scaling the Tri-gate Scaling the Tri-gate

V.V. Frequency AnalysisFrequency Analysis

VI.VI. Future WorkFuture Work

Full-band Particle-based Analysis of Device Scaling For 3D Tri-gate FETs

A simplified flowchart of a particle-A simplified flowchart of a particle-based semiconductor simulation based semiconductor simulation

techniquetechnique

Full-band representation of the Energy-Full-band representation of the Energy-Momentum relation for SiMomentum relation for Si

L X U ,K

5

10

0

-10

-5

S i

Ene

rgy

[meV

]

W ave vector k

Full-band Particle-based Full-band Particle-based simulationsimulation

Full-band Particle-based Analysis of Device Scaling For 3D Tri-gate FETs

Hybrid Full-Band EMC/CMC simulatorHybrid Full-Band EMC/CMC simulator

Full-band representation of electronic Full-band representation of electronic dispersion relation for first valence banddispersion relation for first valence band

Method used in this work-Hybrid CMC/EMC

CMC-Regions where total number of scattering events is high--Saves time

EMC – Regions where total number of scattering events is low-Saves space

Multiple gate devices: Tri-gate FETsMultiple gate devices: Tri-gate FETs

Promising candidate for future nanometer Promising candidate for future nanometer MOSFET applicationsMOSFET applications

Possess high gate-channel Possess high gate-channel controllability controllability

Impressive scalability over Impressive scalability over planar structuresplanar structures

Achieve high drive currentsAchieve high drive currents

*ITRS`2001 published dataF.L. Yang et al. IEDM Tech. Dig. p.255, 2002

Full-band Particle-based Analysis of Device Scaling For 3D Tri-gate FETs

Device Layout of the p-FETDevice Layout of the p-FET

Hsi =50 nm , Wsi =25 nm , Lg=25 nm, doping 129 x 65 x 33 inhomogeneous grid 260,000 particlesP-FETS exhibit record fast transistor switching speed (0.43ps)*P-FETS exhibit record fast transistor switching speed (0.43ps)*

*ITRS`2001 published data

Full-band Particle-based Analysis of Device Scaling For 3D Tri-gate FETs

Device SimulationDevice SimulationCurrent-voltage characteristics

channel direction[nm]

averageholeenergy[ev]

averageholevelocity[x106cm

/s]

0 25 50 75 1000

0 .2

0 .4

0 .6

0 .8

1

1 .2

1

2

3

4

5

6

7

8

9

10

Average energy and velocity

Vg =-1.55 V , Vd =-1.0 V

Velocity overshoot 260,000 particles260,000 particles 24 CPU hrs/ps24 CPU hrs/ps4 ps/bias point4 ps/bias point

Full-band Particle-based Analysis of Device Scaling For 3D Tri-gate FETs

MovieMovie

Scaling effectsScaling effects

Increase in the channel widthIncrease in the channel width - - DIBL(Drain Induced Barrier DIBL(Drain Induced Barrier

Lowering) increasesLowering) increases

Calculation of DIBL

Full-band Particle-based Analysis of Device Scaling For 3D Tri-gate FETs

Scaling effectsScaling effects

Decrease in the channel widthDecrease in the channel width - - Threshold voltage decreasesThreshold voltage decreases Calculation of Threshold voltage

Full-band Particle-based Analysis of Device Scaling For 3D Tri-gate FETs

ScalingScaling effects (contd.) effects (contd.)

Decrease in the channel length-

Increase in peak energy

Increase in electric field

Full-band Particle-based Analysis of Device Scaling For 3D Tri-gate FETs

Dynamic Analysis-Dynamic Analysis- To study the effects of To study the effects of scaling the channel width on the dynamic scaling the channel width on the dynamic

response.response.

-- Sinusoidal excitation method-- Sinusoidal excitation method

VVds ds = -1.35 V = -1.35 V

VVgsgs= -1.75 V= -1.75 V

Perturbations are applied successively to

the gate and drain electrodes at different

frequencies

V d [v]

I d[x103uA/um]

-2 -1 .5 -1 -0 .5 00

1

2

3

4

5

6

7

8

9

10

V g=-1 .35V

Full-band Particle-based Analysis of Device Scaling For 3D Tri-gate FETs

Frequency Analysis-Sinusoidal Frequency Analysis-Sinusoidal excitation methodexcitation method

Applying Sinusoidal excitation on Applying Sinusoidal excitation on the drain electrodethe drain electrode

Applying Sinusoidal excitation on Applying Sinusoidal excitation on the gate electrodethe gate electrode

Gain (Gain (GGv v ))

Full-band Particle-based Analysis of Device Scaling For 3D Tri-gate FETs

Dynamic AnalysisDynamic Analysis

Voltage Gain -Voltage Gain -

Cut-off frequency (Gv =1) :

Channel width 25 nm = 930 HzChannel width 50 nm = 950 Hz

--No significant change in cut-off frequency with decrease in the

channel width

Full-band Particle-based Analysis of Device Scaling For 3D Tri-gate FETs

Current and Future WorkCurrent and Future Work

Further scaling of Tri-gate FETsFurther scaling of Tri-gate FETs -- Scaling the height of the channel-- Scaling the height of the channel Goal- Propose scaling rules/model for Goal- Propose scaling rules/model for

tri-gate FETstri-gate FETs Include Quantum correctionInclude Quantum correction Account for degeneracyAccount for degeneracy

Thank You!Thank You!