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Impact of lanthanum doped zirconium oxide (LaZrO2) gate dielectric material on FinFET inverter

Open Access
|Nov 2020

Figures & Tables

Figure 1:

Bird eye view of SOI n-FinFET: (A) 3D structure of SOI n-FinFET, (B) Side view of device having composite high-k gate dielectric, (C) Layout of n-FINFET device. 
Bird eye view of SOI n-FinFET: (A) 3D structure of SOI n-FinFET, (B) Side view of device having composite high-k gate dielectric, (C) Layout of n-FINFET device. 

Figure 2:

Id-Vg characteristics of FINFET with reference (de Andrade et al., 2011) and simulation.
Id-Vg characteristics of FINFET with reference (de Andrade et al., 2011) and simulation.

Figure 3:

Variation of electrostatic surface potential along the channel length for k = 40, high-k gate dielectric constant.
Variation of electrostatic surface potential along the channel length for k = 40, high-k gate dielectric constant.

Figure 4:

Flowchart of the simulation procedure involved in visual TCAD.
Flowchart of the simulation procedure involved in visual TCAD.

Figure 5:

Transfer characteristics of n-FinFET in log and linear scale for Lg = 14 nm, Vg = 0 to 0.75 V and Vd = 0.75 V.
Transfer characteristics of n-FinFET in log and linear scale for Lg = 14 nm, Vg = 0 to 0.75 V and Vd = 0.75 V.

Figure 6:

Simulated transfer characteristic of n-FinFET and p-FinFET devices.
Simulated transfer characteristic of n-FinFET and p-FinFET devices.

Figure 7:

Output characteristics of n-FinFET and p-FinFET devices for same dimensions: Lg = 14 nm, HFIN = 24 nm, WFIN = 8 nm, Tox = 1.1 nm, WF (N) = 4.6 eV, and k = 40.
Output characteristics of n-FinFET and p-FinFET devices for same dimensions: Lg = 14 nm, HFIN = 24 nm, WFIN = 8 nm, Tox = 1.1 nm, WF (N) = 4.6 eV, and k = 40.

Figure 8:

Schematic layout of optimized FinFET-based inverter circuit with dimensions (HFin = 24 nm, Tox = 1.1 nm, k = 40 and WF = 4.6 eV).
Schematic layout of optimized FinFET-based inverter circuit with dimensions (HFin = 24 nm, Tox = 1.1 nm, k = 40 and WF = 4.6 eV).

Figure 9:

Butterfly curve for proposed FinFET-based inverter (n-FinFET and p-FinFET of equal size) at 0.8 and 0.4 V supply voltage.
Butterfly curve for proposed FinFET-based inverter (n-FinFET and p-FinFET of equal size) at 0.8 and 0.4 V supply voltage.

Impacts of gate dielectric SiO2 and LaZrO2 on the performance of n-FinFET device_

Simulated n-FinFET
Parameters (Vd = 0.75 V, Vg = 0.75 V)Gate dielectric (LaZrO2) k = 40Gate dielectric (SiO2) k = 3.9
ION (A)4.95 × 10−5 1.78 × 10−5
IOFF(A)3.61 × 10−14 5.02E × 10−13
ION/IOFF 1.37 × 109 3.50 × 107
Vt (V)0.2530.207
SS(mV/dec)60.367.02
DIBL(mV/V)10.143
gm (S) (at Vg = 50 mV)2.42 × 10−4 2.69 × 10−5
VEA (V) (at Vg = 50 mV)10.70.88
TGF (V−1) (at Vg = 50 mV)24.5523.2266
gd (S) (at Vg = 50 mV)1.8 × 10−15 1.95 × 10−12
AV (dB) (at Vg = 50 mV)183139.7

Performance analysis of FinFET devices_

n-FinFETp-FinFET
MetricsLin (Vd = 50 mV)Sat (Vd = 0.75 V)Lin (Vd = 50 mV)Sat (Vd = 0.75 V)
ION (A)1.37 × 10−5 4.95 × 10−5 1.81 × 10−5 4.54 × 10−5
IOFF(A)2.64 × 10−14 3.61 × 10−14 2.69 × 10−14 3.98 × 10−14
ION/IOFF 0.51 × 109 1.37 × 109 0.67 × 109 1.14 × 109
SS (mV/dec)59.960.359.960.9
Vt (V)0.2610.2530.2620.253
gm (S)5.88 × 10−5 2.42 × 10−4 4.71 × 10−5 2.33 × 10−4
TGF (V−1)24.6824.5524.6524.37
DIBL (mV/V)10.112.3

Important TCAD device parameters for an inverter design_

Process parametersValue
Design rule unit lambda (µm)0.007
Thickness of substrate region (µm)0.03
Height of fin (µm)0.024
Thickness of gate oxide (µm)0.0011
S/D doping concentration (donor) for nMOS (cm-3)3E20
S/D doping concentration (acceptor) for pMOS (cm−3)3E20
Supply voltage, Vd (V)0.8 V
Thickness of buried oxide (µm)0.02
Thickness of poly-silicon gate (µm)0.002
Thickness of ILD dielectric (µm)0.008
Thickness of ILD Metal 1(µm)0.008
Lateral characteristic length of S/D doping of nMOS (µm)0.004
Vertical characteristic length of S/D doping of nMOS (µm)0.003
Doping concentration in p-type substrate (cm−3)1E16
Doping concentration in body (cm−3)1E17

Impact on noise margin due to temperature and voltage variation for simulated inverter circuit

Temperature (kelvin)Voltage (volts)
Gate dielectric permittivity value(k)273 K300 K398 K0.4 V0.8 V1.2 V
NMH (V)NML (V)NMH (V)NML (V)NMH (V)NML (V)NMH (V)NML (V)NMH (V)NML (V)NMH (V)NML (V)
40(LaZrO2)0.40.3770.3750.3750.350.350.1950.120.3750.3750.550.55

Structural parameters used in simulation *As per ITRS dimensions (Wikipedia 14nm process, 2020)_

Simulation work
Device’s performance parameters(n-FinFET)(p-FinFET)
Gate length, Lg (nm)1414
Transistor fin pitch (nm)4242
Transistor fin width, WFin (nm)88
Transistor fin height, HFin (nm)2424
Workfunction, WF (eV)4.64.6
Gate dielectric permittivity, k 4040
Physical oxide thickness (nm)1.11.1
Supply voltage, Vd (volts)0.750.75
Language: English
Page range: 1 - 10
Submitted on: Sep 19, 2020
Published on: Nov 19, 2020
Published by: Professor Subhas Chandra Mukhopadhyay
In partnership with: Paradigm Publishing Services
Publication frequency: 1 issue per year

© 2020 Gurpurneet Kaur, Sandeep Singh Gill, Munish Rattan, published by Professor Subhas Chandra Mukhopadhyay
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.