Quantum Transport of Transport of Quantum Transport of Quantum - PowerPoint PPT Presentation

Quantum Transport of Transport of Quantum Transport of Quantum Carbon Nanotube Nanotube & & Carbon Bio Sensor Applications Bio Sensor Applications Kazuhiko Matsumoto Osaka University Japan 2.3E-8 4 Drain Voltage (mV) 1.15E-8 2 0 0 -2 -1.15E-8 -4 -2.3E-8 0.0 0.2 0.4 0.6 0.8 1.0 Gate Voltage (V)

Contents Drain Source 1) Carbon Nanotube Quantum Devices Carbon 1. Seamless Transition of Coulomb Blockade Nanoatube Transport to Coherent Transport 73nm 100 4E-6 3.9E-6 80 2) Application of FET Type Bio sensor 3.4E-6 60 Drain Voltage (mV) 40 2.9E-6 1. Top Gate FET type Bio Sensor dI D /dV D (S) 20 2.4E-6 0 1.9E-6 2. Direct modification type Bio-Sensor -20 1.4E-6 -40 9E-7 -60 50 3) Conclusions 4E-7 -80 150 45 1E-5 -1E-7 -100 100 40 -20 -19 -18 -17 -16 -15 Drain Voltage (mV) 5E-6 50 35 d 2 I D /dV D Gate Voltage (V) 0 0 30 -50 Water proof 25 -5E-6 resist 2 -100 20 -1E-5 -150 SiN x -25 -24 -23 -22 -21 -20 15 -25 -20 -15 -10 -5 Gate Voltage (V) SiO 2 IgE Gate Voltage (V) n + -Si Aptamer Aptamer Deby Deby IgE Length Length Drain Back gate ~ 3 nm 1 ~ 2 nm CNT Catal Source yst SiO 2 Si

Carbon Nanotube Quantum Device Carbon Nanotube Quantum Device Carbon Nanotube Quantum Device Carbon Nanotube Quantum Device Carbon Nanotube Source Drain h + Carbon Drain Source Nanoatube 73nm CNT 73nm Quantum Well Drain Drain Source h+ E F E F Drain e/C Source SiO 2 SiO 2 Si Sub. Si Sub. Back Gate Back Gate

Coulomb Blockade Transport : Coulomb Oscillation Coulomb Blockade Transport : Coulomb Oscillation I D V D =11 mV Period of peaks A Δ V G =3V 50 Drain Drain Source V G ~ 0V 40 SiO 2 SiO 2 Si Sub. Si Sub. 30 Back Gate Back Gate V G 20 7.3 K CNT 10 V D =11 mV h+ Source Drain 0 E F E F Carbon -10 0 10 20 Drain e/C Source Nanoatube Gate Voltage V G (V) 73nm

Coulomb Blockade Coulomb Blockade Drain Source Condition Condition 50 CNT CNT Δ V G =3V 40 h+ h + 30 E F E F e/C Drain 20 Source Drain Source 7.3 K 10 V D =11 mV Tunnel Res. R T >> Quantum Res. R Q 0 V G ~ 0 - 1 0 0 1 0 2 0 Heisenberg Rule Δ E •Δ t ≈ h C : Tunnel Capacitance Δ E ≈ h / Δ t = h / CR T R T : Tunnel Resistance Where Δ E << E C (Charging Energy) Quantum T >> h / e 2 = 25.8 k Ω≡ R T << e 2 /2 C Resistance ∴ h / CR 2e 2 =13k Ω =R Q R Q

Coulomb Blockade Coulomb Blockade Drain Source Condition Condition 50 CNT CNT Δ V G =3V 40 h+ h + 30 E F E F e/C Drain 20 Source Drain Source 7.3 K 10 V D =11 mV Tunnel Res. R T >> Quantum Res. R Q 0 - 1 0 0 1 0 2 0 At V G ~0V Large depletion layer at drain Large tunnel resistance R T >R Q Coulomb Confinement

Coexistence of Coulomb Blockade Transport Coexistence of Coulomb Blockade Transport & Coherent Transport & Coherent Transport I D Period of peaks V D =11 mV Δ V G =3V A 50 Drain Drain Source 40 SiO 2 SiO 2 30 Si Sub. Si Sub. CNT Back Gate Back Gate 20 V G 7.3 K h+ 10 V D =11 mV Drain Source EF EF 0 -40-30-20-10 0 10 20 30 40 Drain e/C Source Carbon Gate Voltage (V) Nanoatube 73nm

Coexistence of Coulomb Blockade Transport Coexistence of Coulomb Blockade Transport & Coherent Transport & Coherent Transport Enlargement Period of peaks Δ V G =0.65V 50 50 Δ V G =0.65 V Δ V G =3V 45 40 40 30 35 7.3 K 30 20 V D =11 mV 25 10 20 0 15 -25 -20 -15 -10 -5 -40-30-20-10 0 10 20 30 40 Gate Voltage (V) Gate Voltage (V)

Coexistence of Coulomb Blockade Transport Coexistence of Coulomb Blockade Transport & Coherent Transport & Coherent Transport Coherent Transport = Resonant Tunneling of Hole Coherent Oscillation Quantum Energy Level Discrete Energy Level 50 Δ V G =0.65 V Hole 45 40 Δ E Q Δ V G 35 30 25 Drain Source 20 4 μ m SiO 2 73nm Coulomb Oscillation 15 -25 -20 -15 -10 -5 Gate Electrode Gate Voltage (V)

Coexistence of Coulomb Blockade Transport Coexistence of Coulomb Blockade Transport & Coherent Transport & Coherent Transport Coherent Transport = Resonant Tunneling of Hole Coherent Oscillation Coulmb CNT 50 Gap Δ V G =0.65 V Δ V G =0.65 V 45 Quantum h+ Level 40 35 EF EF 30 e/C Drain Source 25 20 Coulomb Oscillation 15 -25 -20 -15 -10 -5 Gate Voltage (V)

Coherent Transport of Hole : Quantum Interference Coherent Transport of Hole : Quantum Interference Enlargement Period of peaks Δ V G =0.65V 0.2 0.18 7.2 K Drain current (nA) 7.3 K 7.3 K 0.16 Drain current (nA) 0.15 0.14 0.12 0.1 0.1 0.08 0.05 0.06 0 0.04 -25 -24 -23 -22 -21 -20 -40 -20 0 20 40 Gate Voltage (V) Gate Voltage (V)

Coherent Transport of Hole : Quantum Interference Coherent Transport of Hole : Quantum Interference Discrete Energy Level Quantum Energy Level Coherent Oscillation Hole 0.18 7.3 K Δ E Q Δ V G 0.16 Drain current (nA) 0.14 0.12 Drain Source 0.1 4 μ m SiO 2 73nm 0.08 Gate Electrode 0.06 ν 0.04 h α Δ = -25 -24 -23 -22 -21 -20 Δ V G F E Q Gate Voltage (V) 2 Le L=55nm L=73nm Δ V G =0.65V Calculated SEM Observation

Why NO Coulomb oscillation Quite thin depletion layer at drain Quite small tunnel resistance R T ~ R Q V G ~ -22V No Coulomb Confinement Coherent Transport only CNT CNT 0.18 7.3 K 0.16 + h 0.14 h + 0.12 EF EF 0.1 Drain Source 0.08 Drain Source 0.06 0.04 -25 -24 -23 -22 -21 -20 V G ~ -20 Gate Voltage (V) Drain Source Tunnel Res. R T << Quantum Res. R Q

Conductance of Barrier G Conductance of Barrier G CNT h+ G : Conductance of Barrier Γ Γ 2 2 ( ) e e E F E = = ε F L R G T ( ) π π ε + Γ + Γ 0 2 Drain h 2 h Source 4 h h L R T 0 ( ε ) : Tunneling Probability Γ : Transfer Probability I ν h dE dk h ( ) Γ = φ = + Γ= Γ L + Γ R = T T φ 0 L R dk d 2 L FWHM Γ = Γ L Γ + 2 L + = Γ R T T T 0 ( ε ) = T L + T R = Γ 2 L ν L R h h v V Resonant Peak Γ= Γ L + Γ R T 0 ( ε ) G

Conductance of Barrier G Conductance of Barrier G CNT h+ For Low Vg E Γ= Γ L + Γ R = 20mV F E F Drain Source T 0 ( ε ) : Tunneling Probability 2 L (Γ L + Γ R ) = 1.53x10 -1 T 0 ( ε ) = h v F I v F =3x10 7 m/sec 20mV G : Conductance of Barrier FWHM Γ = Γ L Γ + e 2 T 0 ( ε ) = 11.8 μ S G = R π h V R : Tunneling Resistance Resonant Peak R = 1/G = 85 k Ω >> R 0 = 13 k Ω

Tunneling Resistance R by Different V G Tunneling Resistance R by Different V G Drain Source For Low Vg CNT R : Tunneling Resistance h + R = 85 k Ω ~ 7 R 0 >> R 0 = 13 k Ω Drain Source Coulomb confinement Coulomb Oscillation For High Vg CNT R : Tunneling Resistance h + R = 42 k Ω ~ 3 R 0 ~ R 0 = 13 k Ω Drain Source NO Coulomb confinement Coherent Oscillation

50 CNT CNT Δ V G =3V 40 h+ h + 30 E F E F e/C Drain 20 Source Drain Source 7.3 K 10 V D =11 mV Tunnel Res. R T >> Quantum Res. R Q 0 V G ~ 0 - 1 0 0 1 0 2 0 CNT 50 CNT 45 h+ h + 40 E F 35 E F e/C Drain Drain Source 30 Sourc 25 e 20 Tunnel Res. R T ~ Quantum Res. R Q 15 V G ~ -10 -25 -20 -15 -10 -5 Gate Voltage (V) CNT CNT 0.18 7.3 K 0.16 + h 0.14 h + 0.12 EF EF 0.1 Drain Source 0.08 Drain Source 0.06 0.04 -25 -24 -23 -22 -21 -20 Tunnel Res. R T << Quantum Res. R Q V G ~ -20 Gate Voltage (V)

Contents Drain Source 1) Carbon Nanotube Quantum Devices Carbon 1. Seamless Transition of Coulomb Blockade Nanoatube Transport to Coherent Transport 73nm 100 4E-6 3.9E-6 80 2) Application of FET Type Bio sensor 3.4E-6 60 Drain Voltage (mV) 40 2.9E-6 1. Top Gate FET type Bio Sensor dI D /dV D (S) 20 2.4E-6 0 1.9E-6 2. Direct modification type Bio-Sensor -20 1.4E-6 -40 9E-7 -60 50 3) Conclusions 4E-7 -80 150 45 1E-5 -1E-7 -100 100 40 -20 -19 -18 -17 -16 -15 Drain Voltage (mV) 5E-6 50 35 d 2 I D /dV D Gate Voltage (V) 0 0 30 -50 Water proof 25 -5E-6 resist 2 -100 20 -1E-5 -150 SiN x -25 -24 -23 -22 -21 -20 15 -25 -20 -15 -10 -5 Gate Voltage (V) SiO 2 IgE Gate Voltage (V) n + -Si Aptamer Aptamer Deby Deby IgE Length Length Drain Back gate ~ 3 nm 1 ~ 2 nm CNT Catal Source yst SiO 2 Si

Antigen / Antibody Reaction : Immunoassay （免疫） 抗原（例えばウイルス） Antigen Antigen/Antibody Selective Reaction Antibody （抗体） Immune （免疫） Antigen is eaten.

Electrical Detection of Antigen-Antibody Electrical Detection of Antigen-Antibody Reaction by Carbon Nanotube FET Reaction by Carbon Nanotube FET （抗原） Antigen 10 6 PSA ： Pig Serum Albumin （抗体） Anti-Body a-PSA a-PSA 100 nm Top-gate SEM image of top-gate with a-PSA of CNT-FET with Water proof resist immobilized a-PSA. SiN x 窓 (100 μ m × 100 μ m) SiO 2 n + -Si Drain Top gate Back gate CNT Source Catalyst Drain Source Catalyst

Electrical Detection of Antigen-Antibody Reaction Analyzer Ag/AgCl Gate Antigen PSA Antibody a-PSA SiN x Top Gate Antigen/Antibody Drain Source Reaction SiO 2 CNT n + -Si Reduction of Δ I D Back Gate - 1500 - PSA Δ I D Antigen Drain I (nA) - 1000 a-PSA Antibody 500 Top Gate - 0 CNT 0.0 0.2 0.4 0.6 0.8 1.0 Electron Current Drain V (V)