Department of Material Science, University of Milano Bicocca, Milano, Italy 2)

Size: px

Start display at page:

Download "Department of Material Science, University of Milano Bicocca, Milano, Italy 2)"

Rosalyn Barton
8 years ago
Views:

1 Marco Fanciulli 1,2, Enrico Prati 2, Matteo Belli 2, Giovanni Mazzeo 1, Carmen Canevali 1, Alberto Debernardi 2, Guido Petretto 1,2, Marco De Michielis 2, Antonio Vellei 1,2 1) Department of Material Science, University of Milano Bicocca, Milano, Italy 2) MDM Laboratory, CNR - IMM, Agrate Brianza, Italy.

2 Main Objectives Echo Intensity [arb. units] 1. Single donor charge/spin detection and manipulation for classical and quantum information processing 2. Silicon nanostructures (SiNWs, SiQDs) fabrication and doping with top down approaches 3. Spin coherence and relaxation in group IV semic. 4. Development of advanced electrical and spin resonance techniques 5. Theoretical study of donors and conduction electrons in silicon nanostructures using different approaches (EMT, ab-initio, k p) Si 28 :P Magnetic Field [G] 2

3 Growth and Processing Facilities 1 m 2 clean room class 1 2 Atomic Layer Deposition (ALD) +Ozone and in-situ characterization Omicron UHV system with MBE chamber and in-situ variable temperature AFM/STM, XPS, LEISS MOCVD (Chalcogenides, Ge NWs) Cluster Tool (ALD, Sputtering, Evaporator) Thermal and e-beam evaporator Wet benches for wafer cleaning Rapid Thermal Processing (RTP) system Photolithography MBE e-beam lithography Microscope Profilometer Plasma Etcher MOCVD Bonders Thermal/e-beam deposition RTP ALD Yellow room 3

4 Characterization Facilities Scanning Probes: AFM, STM, MFM/EFM, SCM, SThM, SNOM UHV cryogenic VT (25-15 K) AFM/STM system X-ray diffraction (XRD) and reflectivity (XRR) TXRF/XRR SEM XPS (in-situ), XPS-mono (ex-situ) LEIS ToF-SIMS Electrical Characterization (I-V, C-V, C-t,...), DLTS, Noise, IETS Optical Techniques ( -RAMAN and PL visible and UV), FT-IR, IPE (4-4 K), Ellipsometry (ex-situ and in-situ) Conversion Electron Mössbauer Spectroscopy (CEMS) Electron Spin Resonance Spectroscopy (ESR), EDMR (X and Q band) (2-6 K), ENDOR (X-band) Four probe cryomanipulator (4-4 K) Cryomagnetic system (12 T, 3 mk, 4 GHz and 2 GHz probes) Multi-frequency EDMR Pulsed EPR (X-band) UHV VT AFM/STM 4-4 K; electrical testing EDMR 12 T, 26 mk, up to 2GHz 4

5 Projects Commessa: MD.P6.36 ( ), Materiali e nanostrutture per elettronica a singolo atomo e spintronica (M. Fanciulli) National Projects: ELIOS (Cariplo, M. Fanciulli) International Projects: AFSID (FP7, M. Fanciulli) Bilaterale Italia-Giappone (MAE, E. Prati) 5

6 Electron spin resonance in SiNWs EDMR intensity (arb. un.) E-beam lithography Metal-assisted chemical etching Data Fit P doublet Pb, Pb E'-like magnetic field (G) M. Fanciulli et al., NNL in press 6

7 Spin coherence and relaxation in silicon Echo Intensity [arb. units] Echo Intensity [arb. units] Echo Intensity [arb. units] Echo Intensity [arb. units] Echo Intensity [arb. units] Echo Intensity [arb. units] 5 T 2 ~ ms (< 1 K) Si-28 Si:P, SiGe:P Spin and instantaneus diffusion Si:Bi Magnetic Field [G] sec] 25 2 Si-nat Magnetic Field [Gauss] sec] 1 SiGe-nat Magnetic Fiedl [G] sec] M. Fanciulli et al., Physica B (23) A. Ferretti et al., Phys. Rev. B (25) M. Belli, A. Abrosimov, and M. Fanciulli submitted 7

8 Theory: donors in Si nanostructures (QDs and SINWs) Enery levels and HFC as a function of electric field Electronic structure of Se in Si-NW Debernardi et al. Phys. Rev. B. 81, (21) 8

9 Towards single spin detection and manipulation 1. Noise in nanoscale MOSFETs 2. Single Atom Quantum Devices and electrical detection of single spin 9

Capture and emission in a point like defect Samples fabricated by STMicroelectronics M. Fanciulli et al., AIP 8, 125, (25) E. Prati et al., Phys. Lett. A (27) E. Prati et al., Phys. Lett. A (28) E.

10 Capture and emission in a point like defect Samples fabricated by STMicroelectronics M. Fanciulli et al., AIP 8, 125, (25) E. Prati et al., Phys. Lett. A (27) E. Prati et al., Phys. Lett. A (28) E. Prati et al., Jour. Appl. Phys. (28) E. Prati et al., Jour. Appl. Phys. (28) Effects of -microwave irradiation -low temperature -static magnetic field 1

11 Probing single electron occupation..by the capture and emission times of a single defect at the Si/SiO 2 in commercial NanoFET Tnom =.29 K Generalized temperature 1/kb by a finite grand canonical ensemble T2des =.8 K about 16-2 (small N) electrons E. Prati et al., Phys. Rev. B (26) E. Prati, J, Stat. Phys. (21) E. Prati et al., Appl. Phys. Lett. (21) 11

] 21 UniMelbourne [Tan et al, Nano Lett.

12 Recent results: single atom quantum devices V d (mv) 26 TU Delft (IMEC) [Lansbergen et al, PRL] 28 MDM (STM) [Prati et al, PRB] 29 CEA (LETI) [Pierre et al, Nat. Nanotech.] 21 UniMelbourne [Tan et al, Nano Lett.] TU Delft, MDM, CEA, LETI, UniMelbourne are also partners of AFSID consortium in the FP VII 5 E c mev 35 mev E cg (mev) 3.17E E-5 1.E-5 G(e 2 /h) 12

13 Double/triple quantum dot with two gates Samples fabricated at LETI EU FP VII AFSID Project M. Pierre et al., Appl. Phys. Lett. (21) 13

14 Stability diagram of the single donor V d (mv) E c E mev 35 mev E cg (mev) G(e 2 /h) 5.574E-5 1.E-5 R Microwave v d w _ V G Loop + b Cg /Cg+Cs+Cd Samples fabricated by Numonyx E. Prati et al., Phys. Rev. B (29) Photon assisted Tunneling with microwave irradiation deb/edvg ( mev b.14 (1 mv=.14 14

15 Donor and electrostatic quantum dot in parallel Donor: spin degenerate Ground State and spin degenerate Excited State 15.4 corresponds to the valley splitting in the nanostructu QD: metallic dot Samples fabricated by Numonyx E. Prati et al., Appl. Phys. Lett. (211) 15

of the QD with the 3 electrons already bound to the

16 Adiabatic control of the exchange coupling Simulation J exchange coupling of the Nth electron of the QD with the 3 electrons already bound to the donor Added a mutual Capacitance of 5 af in the simulation 16

bulk 5. Surface Analysis Why surface Analysis? Introduction Methods: XPS, AES, RBS

bulk 5. Surface Analysis Why surface Analysis? Introduction Methods: XPS, AES, RBS 5. Surface Analysis Introduction Methods: XPS, AES, RBS Autumn 2011 Experimental Methods in Physics Marco Cantoni Why surface Analysis? Bulk: structural function Electrical/thermal conduction Volume increases