NATO Advanced Research Workshop on Fundamental and Applied NanoElectroMagnetics (FANEM), May 25-27, 2015, Minsk, Belarus.

Transcription

1 NATO Advanced Research Workshop on Fundamental and Applied NanoElectroMagnetics (FANEM), May 25-27, 2015, Minsk, Belarus 2D Crystals for Nanoelectronics and Beyond.. Kaustav Banerjee Department of Electrical and Computer Engineering University of California, anta Barbara, CA May 25, 2015

2 . Borkar (Intel) 1.6X 6X Dragon Energy On-die global interconnect energy scales slower than compute On-die data movement energy will start to dominate K. Banerjee et al., IEEE Trans. Electron Devices, 49(11), pp , Need Green Transistors Need Green Interconnects

3 2D Electronic Materials Family Tree Graphene family TMD family h-bn (dielectric) (E g >5eV) Nbe 2, etc (superconductor) Graphene (semi-metal) (E g =0eV) ilicine (semiconductor) (E g =0.6 ev, experimentally) VO 2, V 2, etc (metals) Mo 2, We 2, etc (semiconductors) CrO 2, Cr 2, etc (half-metals) (0<E g <1eV) Other families Ti 2 C, Ti 2 CF 2 Black Phosphorus etc. Kaustav Banerjee, UC anta Barbara kaustav@ece.ucsb.edu May 25, 2015, FANEM Workshop 3

4 few Å 1.2 nm deep Oxide Advantages of 2D Materials (1/2) Potato-like 3D Materials Increased EOT Gate Degraded Channel Potential (V Ch ) Gate C G C C Channel C DC D Covalent bonds everywhere Mobile charges centroid V Ch CG C C C G C DC V G Onion-like 2D Materials Gate Advanced Topology & Controllable V Ch Layered structure Covalent bonds Can be exfoliated Van der Waals force few Å Carriers confined Gate Oxide Channel ubstrate Gate Oxide Oxide Gate D D Thin Channel: Low C C, C DC Kaustav Banerjee, UC anta Barbara kaustav@ece.ucsb.edu May 25, 2015, FANEM Workshop 4

5 Advantages of 2D Materials (2/2) Potato-like 3D Materials Thickness Roughness Band gap Variation Performance Variation Interface Variations (Traps) Unsaturated atoms on surfaces Dangling bonds (traps) EC Eg EV Covalent bonds everywhere Onion-like 2D Materials Layered structure Covalent bonds Controllable # of Layers Controllable Band gaps Pristine Interfaces (No interface traps) aturated atoms Can be exfoliated Dirac Point Ec 5 Ev No dangling bonds Van der Waals force Graphene h-bn Mo2 We2 few Å Kaustav Banerjee, UC anta Barbara kaustav@ece.ucsb.edu May 25, 2015, FANEM Workshop 5

6 2D Materials UCB Devices, Interconnects, Circuits Key Issues in 2D Device Design Contact Doping dopant Interface Contact Doping Interface Mo 2 Explore Green Devices/Circuits and Applications: CMO and Beyond 2D Material election and FET Design for ITR Roadmap Novel Heterostructures and Devices (2D Tunnel-FETs) Flexible and Transparent 2D Circuits/ensors Kaustav Banerjee, UC anta Barbara kaustav@ece.ucsb.edu May 25, 2015, FANEM Workshop 6

7 Understanding and Optimizing Metal-TMD Contacts J. Kang, W. Liu, D. arkar, D. Jena and K. Banerjee, Phys. Rev. X, Vol. 4, No. 3, pp , Tunnel barrier chottky barrier Orbital overlap Treatment of vdw force in DFT (bulk metal-tmd) for the first time Widest diversity of metals and TMDs First study of metal-tmd edge contacts Fermi level pinning revealed beyond chottky theory Kaustav Banerjee, UC anta Barbara May 25, 2015, FANEM Workshop 7

8 R (kω.μm) Contact Engineered TMD FETs Guided by DFT First High-Performance Monolayer n-type We 2 FET W. Liu, J. Kang, D. arkar, Y. Khatami, D. Jena and K. Banerjee, Nano Lett., Vol. 13, no. 5, pp , (a) 3L Optical Image 2L 1L High mobility: 142 cm 2 /V.s Record I ON : 210 µa/µm High-Performance Mo 2 FET with Mo Contacts J. Kang, W. Liu and K. Banerjee, App. Phys. Lett.,104, 9, , Mo Mo Mo Mo Mo Mo Mo Mo Mo Mo Mo Mo Mo trong bonding (Å -3 ) Mo Optical Image EM Image R total = R channel +2 R total R channel R contact 4 layers R contact 2 kω.μm V bg (V) Kaustav Banerjee, UC anta Barbara kaustav@ece.ucsb.edu May 25, 2015, FANEM Workshop 8

9 Doping of TMDs using Metallic Nanoparticles D. arkar, X. Xie, J. Kang, H. Zhang, W. Liu, J. Navarrete, M. Moskovits and K. Banerjee, Nano Letters, vol. 15, no. 5, pp , Back-gate Vth shift up to 137 V (monolayer Mo 2 FET) Both n- and p-type are available First p-type doping of We 2 FET imple/effective/table way of doping as well as sensing Metal Mo 2 4 nm Doping Hydrogen Gas ensing 50 nm Kaustav Banerjee, UC anta Barbara kaustav@ece.ucsb.edu May 25, 2015, FANEM Workshop 9

10 Understanding TMD-Dielectric Interfaces J. Kang, W. Liu and K. Banerjee, 45 th IEEE IC, Dec , an Diego, pp. 1-2, Mo 2 H O io dipoles + - H O Mo 2 trap Interfaces hold the key to device performance Revealing microscopic physics of 2D-dielectric interfaces Dipoles/traps evaluated atomically Compared 5 dielectrics h-bn buffer layer is preferred io 2 Mo 2 h-bn HfO 2 Kaustav Banerjee, UC anta Barbara kaustav@ece.ucsb.edu May 25, 2015, FANEM Workshop 10

11 Interface Characterization: Low-Frequency Noise X. Xie, D. arkar, W. Liu, J. Kang, O. Marinov, M. J. Deen and K. Banerjee, AC Nano, Vol. 8, No. 6, pp , PR residue Low-frequency noise in bilayer Mo 2 field-effect transistor Mo 2 Existence and hift of Noise Peak io 2 before annealing after annealing 10-5 Noise Peak before annealing Interface vdw gaps induce noise peak in 2D materials The first theoretical model explaining the noise peaks in 2D materials Annealing process reduces noise Noise Peak after annealing V G (V) Kaustav Banerjee, UC anta Barbara kaustav@ece.ucsb.edu May 25, 2015, FANEM Workshop 11

12 Compact Modeling for Circuit Exploration & tudying Effects of Parameter Variation First Physics based Compact Model for 2D TMD FET W. Cao, J. Kang, W. Liu and K. Banerjee, IEEE Trans. Electron Devices, 61, 12, , Model available on: I. tart from fundamental: Gauss s law II. Develop a modified Poisson s equation specifically for 2D channel 2 d 2 2 dx q( n N ) 2D T 2D 2D imp n2 DO2 ( E) f ( E E ) de D D F E c DO g g m * s i i 2D 2 i 1,2 2 III. Use Drift-Diffusion equation for current transport dv ( x) Ids ( x) qwn2 D( x) ( x) dx IV. Explicit intrinsic drain current expression obtained I ds T qw q 0 L T q 2D 2D 2D 2D 2 kt ( ) 2 Nimp D q 2 2 D 2 Kaustav Banerjee, UC anta Barbara kaustav@ece.ucsb.edu May 25, 2015, FANEM Workshop 12

13 Tunnel Leakage Carrier Velocity 2D FET Material election for ITR 2026 (5.9 nm) W. Cao, J. Kang, D. arkar, W. Liu and K. Banerjee, IEDM 2014, pp Germanane OU 2013 We 2 (for hole), Berkeley 2012 We 2 (for electron), UCB 2013 Direct Tunneling Ch D Mobility (cm 2 /V s) LTP Black P (low-m direction) Renmin Univ ilicane ( low-m direction) NU 2014 HP Black P (high-m direction) Renmin Univ W 2 Mo 2 Yonsei Univ Moe 2 EPFL 2011 UT Austin 2012 UCB Effective Mass m (m 0 ) Effective mass should be in suitable region T e a m v k m HP: High Performance m LTP: Low tandby Power Improving mobility only does not work for 5.9 nm node! m Kaustav Banerjee, UC anta Barbara kaustav@ece.ucsb.edu May 25, 2015, FANEM Workshop 13

14 log(i D ) An ideal switch Boltzmann tail 2D Band-to-Band Tunneling FET Y. Khatami and K. Banerjee, IEEE Trans. Electron Devices, 56(11), pp , MOFET Boltzmann tail TFET ΔV gs Δlog(I d ) olid-state devices = Δlog(Id ) V th ΔV gs V G I OFF E C E V ource Drain Channel 60 mv/dec. ource < 60 mv/dec. I OFF E C E V Channel Drain Advantages of 2D TFET: Heterojunctions with low band overlap Better electrostatics mall tunneling barrier width Pristine interfaces W. Cao, D. arkar, Y. Khatami, J. Kang and K. Banerjee, AIP Advances, 4, , Kaustav Banerjee, UC anta Barbara kaustav@ece.ucsb.edu May 25, 2015, FANEM Workshop 14

15 Minimum Delay (s) Dynamic Power (W) Noise Margin (/VDD) Inverter Gain All-Graphene Logic Circuits Making Interconnects and Transistors with the same Material J. Kang, D. arkar, Y. Khatami and K. Banerjee, Appl. Phys. Lett., Vol. 103, No. 8, , Performance Evaluation Inverter Noise Margin Inverter Gain V DD (V) V DD (V) Inverter Delay Power Consumption HP-CMO Few Fabrication teps Low Contact Resistance Higher Performances over CMO V DD (V) Max Frequency (Hz) All-Graphene Monolithic Logic Circuits 22nm-CMO 22nm-CMO (High (Low Power Model) Performance Model) Kaustav Banerjee, UC anta Barbara kaustav@ece.ucsb.edu May 25, 2015, FANEM Workshop 15

16 First Demonstration of 2D TMD FET Biosensor D. arkar, W. Liu, X. Xie, A. Anselmo,. Mitragotri and K. Banerjee., AC Nano, 8 (4), pp , Label Free - Fast -Low-Cost Kaustav Banerjee, UC anta Barbara kaustav@ece.ucsb.edu May 25, 2015, FANEM Workshop 17

17 Ultra-Low Power and Ultra-ensitive Tunnel-FET Biosensors D. arkar and K. Banerjee, Appl. Phys. Lett., 100, , target biomolecules G Boltzmann tail (e - density) E C E C (BTB Tunnel Current) 10 5 X receptor molecules D graphene channel After conjugation E V ource Barrier Channel ON Current OFF Current Drain (Nearly No Leakage) TFET Biosensor in Research Highlights of Nature Nanotechnology D. arkar and K. Banerjee Kaustav Banerjee, UC anta Barbara kaustav@ece.ucsb.edu May 25, 2015, FANEM Workshop 18

18 Graphene Passive Devices - Early Works (UCB) Nano-carbon on-chip inductors large momentum relaxation time low-loss Graphene interconnects: Xu et al., IEDM 2008, pp Xu et al., TED 56, 8, , metal end contacts Design Analysis of CNT Inductors H. Li, et al., TED 56, 10 (2009) CNT bundles First Demonstration of Horizontal CNT Interconnects & Inductors H. Li, et al., TED 60, 9 (2013) 2014 seamless turns Design Analysis of Graphene Inductors D. arkar, et al., TED 58, 3 (2011) First Demonstration of Graphene Inductors X. Li/J. Kang et al., IEDM 2014 multilayer graphene

19 All-2D Circuits for Flexible Electronics First Demonstration of Graphene Inductors X. Li, J. Kang, X. Xie, W. Liu, D. arkar, J. Mao, and K. Banerjee, IEDM 2014, pp Military Use Consumer Electronics Medical Use Child afety Phase Detector Voltage Controlled Oscillator (VCO) designed based on Graphene Inductors First Demonstration of Graphene Inductors Phase-Locked Loop FM Demodulator Circuit Low Pass Filter Voltage Controlled Oscillator Amplifier Graphene Inductors All-2D Analog Circuits Graphene Interconnect Oscillation Frequency Range: GHz

20 Future Perspectives- 2D Crystals for mart Life Flexible Electronics mart creens Graphene Transparent Electrode bilayer graphene Point-of-Care Mobile Health Chem. Mat (UCB) iwatch monolayer graphene 2D Materials Graphene Inductors Ultra-ensitive Mo2 Biosensors Ultra-thin body mooth surfaces Range of materials 2D Metal VO2, Ti2C, etc Materials by design new layered materials 2D Insulator h-bn, etc IEDM 2014 (UCB) AC Nano 2014 (UCB) 2D emiconductors Mo2, We2, etc Ultra high-density /low-power hardware Energy-Efficient ICs High-Density Memory 2D emi-metal Graphene, etc to enable Big Data High-Performance 2D Transistors 2D Tunnel-FETs Ultra-thin NV Memory Nano Letters 2013 (UCB) IEEE TED 2014 (UCB) Kaustav Banerjee UC anta Barbara 3D ICs with 2D May 25, 2015, FANEMWorkshop Internet of Things ocial Media Homeland ecurity

21 A creative child Kaustav Banerjee, UC anta Barbara May 25, 2015, FANEM Workshop 22

22 2D semiconductor 2D half-metal 2D semi-metal 2D dielectric 2D metal We researchers A future 2D Legoland G D GNRTFET Biosensor G D GNRTFET Inverter 1 Inverter 2 V DD TG P-NDR V DD V in GND BG BG TG N-NDR V out NDR-based RAM V out1 V out2 V in GND All-Graphene Logic Circuit Kaustav Banerjee, UC anta Barbara kaustav@ece.ucsb.edu May 25, 2015, FANEM Workshop 23