CVD Diamond based Active Devices Viareggio – CAEN June 24th, 2011 Paolo Calvani S2DEL DiaC2Lab S2DEL (Diamond & Carbon Compounds Lab) Solid State and Diamond Electronics Lab IMIP - CNR - Montelibretti (RM) Università degli Studi “Roma Tre” Elettronica basata sul Diamante: Applicazioni nella Fisica delle Alte Energie, Fisica Nucleare, Astrofisica, Fisica Medica ed Elettronica di Potenza Viareggio – CAEN June 24th, 2011 Daniele M. Trucchi Paolo Calvani Alessandro Bellucci Emilia Cappelli Stefano Orlando Elettronica basata sul Diamante: Applicazioni nella Fisica delle Alte Energie, Fisica Nucleare, Astrofisica, Fisica Medica ed Elettronica di Potenza CNR-IMIP: Know-How & Projects 1989-1995 Study of Nucleation and Growth Mechanisms of CVD Diamond Mechanical Applications 1995-1999 CVD Diamond protective coatings of cutting tools Coordination of MURST-CNR 5% Project 2003-2006 Development of high-tech materials and ceramic coatings ENEA-MIUR “PROMOMAT” Strategic Project Viareggio – CAEN June 24th, 2011 Electronic Applications 1999-2001 Secondary electron emission amplifiers for scanning electron microscopy MADESS II Applied Research Project 2000-2002 VUV & DUV Radiation Detectors in collaboration with S2DEL – Univ. Roma Tre ASI ARS1/R07/01 Aerospace Project 2001-2005 Poly-Diamond Radiation Dosimeters for Radiation Therapy Coordination of European Project “DIAMOND” G5RD-CT01-00603 2003-2007 Nanostructured Carbon and graphene Structures for Opto-Electronic applications FIRB Project “Micro & Nanocarbon” & FISR Project “High Density Memories” 2008-2010 Systems for direct nuclear-to-electric energy conversion Coordination of CNR-RSTL “ECO-Diamond” Project 2008-today Development of Single-Crystal Diamond dosimeters in collaboration with S2DEL - Univ. Roma Tre 2010-2013 Thermionic-thermoelectric conversion module for solar concentrated systems E2PHEST2US Project Elettronica basata sul Diamante: Applicazioni nella Fisica delle Alte Energie, Fisica Nucleare, Astrofisica, Fisica Medica ed Elettronica di Potenza CNR-IMIP: Facilities Material Production Viareggio – CAEN June 24th, 2011 ~ Hot Filament CVD for diamond film deposition Characterization of Chemical-Physical Properties Spectroscopy Technological Processes for Device Fabrication Raman & IR MW-CVD for surface hydrogen termination Microwave CVD for diamond (doped) film deposition Characterization of Device Performance Vacuum & Temperature Electronic Characterization (VTEC) (10-9 Torr, T=771200 K) for Thermionic Emission Secondary Electron Emission Characterization Setup X-Ray Photoconductivity Setup Spectral (UV-VisNIR) Photoconductivity Setup Spectral Photometry Microscopy RF Sputtering for deposition of metals Ti, Al, Cr, … SEM & EDS Pulsed laser (Excimer & Nd:YAG) ablation for (nanostructured) thin-film deposition of carbon, carbides, refractory metals Four-Point Probe under vacuum, T=25-400 °C AFM Seebeck Effect Measurement System for Thermoelectric Characterization Elettronica basata sul Diamante: Applicazioni nella Fisica delle Alte Energie, Fisica Nucleare, Astrofisica, Fisica Medica ed Elettronica di Potenza Diamond Electronic Properties Band gap Thermal conductivity Breakdown electric field Eb Mobility Carriers sat. velocity vsat Dielectric constant εr eV W/cmK 106 V/cm cm2/Vs 107 cm/s - Diamond 5.5 20 10 2000 - h 1.0 5.7 Gallium nitride 3.4 1.5 2.5 2000 2.5 8.9 Silicon carbide 3.27 4.9 3.0 1000 2.0 9.7 Gallium Arsenide 1.42 0.55 0.4 8500 1.29 12.9 Silicon 1.12 1.5 0.3 1400 1.0 11.8 Germanium 0.67 0.58 0.1 3900 1.0 16.2 Viareggio – CAEN June 24th, 2011 Material High Frequency – High Power Field Effect Transistors UV Power Switches Renewable Energies Conversion Stages 5 Elettronica basata sul Diamante: Applicazioni nella Fisica delle Alte Energie, Fisica Nucleare, Astrofisica, Fisica Medica ed Elettronica di Potenza High Frequency – High Power Field Effect Transistors S2DEL Viareggio – CAEN June 24th, 2011 Plasma assisted Hydrogen termination of CVD Diamond induces p-type conductive channel Evolution of the band bending, activated by air exposure, during the electron transfer process at the interface between diamond and water layer[b]: density-of-states (DOS) is changing from 3D to 2D: 2DHG Fabricated by S2DEL and IFN-CNR 6 Elettronica basata sul Diamante: Applicazioni nella Fisica delle Alte Energie, Fisica Nucleare, Astrofisica, Fisica Medica ed Elettronica di Potenza RF Power Characterization by Politecnico di Torino CLASS A @ 2GHz Pout=0.2 W/mm Gain=8 dB PAE=21.3% S2DEL Viareggio – CAEN June 24th, 2011 Pout @ 1GHz ~ 0.8 W/mm[a] Best result for Polycrystalline Diamond LG=200nm, WG=50um VDS=-14 V, VGS=-0.3 V fMAX = 15.2 GHz ft = 6.2 GHz Maximum VDS applied=80 V Eapplied= 2 MV/cm Channel conductance is always positive. No self heating effects! Elettronica basata sul Diamante: Applicazioni nella Fisica delle Alte Energie, Fisica Nucleare, Astrofisica, Fisica Medica ed Elettronica di Potenza Polycrystalline Diamond PolyD4 by Russian Academy of Sciences -20 dB/dec. P7MS by Russian Academy of Sciences Wg=50 μm WG=25 μm Gain = 15 dB@ 1 GHz Viareggio – CAEN June 24th, 2011 Single Crystal Diamond Gain = 22 dB @ 1 GHz fMAX =26.3 GHz fMAX = 23.7 GHz fT = 6.9 GHz LG=0.2 μm fT = 13.2 GHz VGS=-0.2 V, VDS=-10 V Eapplied= 0.5 MV/cm S2DEL RF Small Signal Characterization in collaboration with by Tor Vergata University Elettronica basata sul Diamante: Applicazioni nella Fisica delle Alte Energie, Fisica Nucleare, Astrofisica, Fisica Medica ed Elettronica di Potenza Polycrystalline Diamond PolyD4 by Russian Academy of Sciences S2DEL Viareggio – CAEN June 24th, 2011 -20 dB/dec. Gain = 16 dB @1GHz Lg=0.2 μm, Wg=25 μm VGS=0.0 V, VDS=-35 V fMAX = 35 GHz fT = 10 GHz Eapplied= 1.75 MV/cm Elettronica basata sul Diamante: Applicazioni nella Fisica delle Alte Energie, Fisica Nucleare, Astrofisica, Fisica Medica ed Elettronica di Potenza Viareggio – CAEN June 24th, 2011 S2DEL Elettronica basata sul Diamante: Applicazioni nella Fisica delle Alte Energie, Fisica Nucleare, Astrofisica, Fisica Medica ed Elettronica di Potenza UV POWER SWITCHES VDS Lecroy WavePro 960 2 GHz 16Gs/s digital oscilloscope Picosecond 5550B 18 GHz Bias tee DUT Si diode (for trigger) =193 nm 50 Oscilloscope input resistance x 1,0 GPIB Laser pulse shape recorded by vacuum phototube 0,8 Normalized signal Viareggio – CAEN June 24th, 2011 Neweks PSX 100 excimer laser Filled with ArF gas mixture S2DEL 0,6 VGS (Keithley 617) 0,4 0,2 0,0 -5 10 -9 0 -9 5 10 -8 1 10 Time (ns) -8 1,5 10 2 10 -8 Elettronica basata sul Diamante: Applicazioni nella Fisica delle Alte Energie, Fisica Nucleare, Astrofisica, Fisica Medica ed Elettronica di Potenza 12/23 Source Drain G UV generated carriers diamond 0 VDS=-9.6 V V =-10.0 V GS 0 1,5 10 V =-8.6 V GS V =-7.0 V GS 0 1 10 V =-5.0 V GS 5 10 -1 V =-2.5 V V =0.0 V GS GS 0 V =+1.0 V GS -1 -5 10 -10 0 10 Time (ns) 20 30 Drain-Source Photogenerated Voltage (V) Drain-Source Photogenerated Voltage (V) Viareggio – CAEN June 24th, 2011 2 10 6 10-1 VGS=-3.4 V V =-6.0 V 5 10-1 DS V =-5.0 V V =-4.0 V 4 10-1 DS DS 3 10-1 V =-3.0 V DS 2 10-1 V =-2.5 V DS V =-0.5 V DS 1 10-1 0 -1 10-1 V =-0.0 V DS -2 10-1 -10 0 10 Time (ns) 20 30 Elettronica basata sul Diamante: Applicazioni nella Fisica delle Alte Energie, Fisica Nucleare, Astrofisica, Fisica Medica ed Elettronica di Potenza 13/23 Source Drain G UV generated carriers 0,07 0,06 Peak Amplitude (V) Viareggio – CAEN June 24th, 2011 diamond 0,05 0,04 0,03 0,02 0,01 0 -0,01 0 0,02 V 0,04 DD (V) 0,06 0,08 Elettronica basata sul Diamante: Applicazioni nella Fisica delle Alte Energie, Fisica Nucleare, Astrofisica, Fisica Medica ed Elettronica di Potenza Renewable Energies Conversion Stage Viareggio – CAEN June 24th, 2011 EU Project E2PHEST2US’ Duration: 3 years (Jan 2010 - Jan 2013) •Total Project Cost: 2.68 M€ •Total EU Funding: 1.98 M€ Partners: •CNR (Italy, Scientific Coordination) •CRR (Italy, Management Coordination) •SHAP (Italy) •Tel Aviv University (Israel) •Tubitak (Turkey) •Prysmian (Multinational Industry) •Maya (San Marino) *For details, http://www.ephestus.eu Elettronica basata sul Diamante: Applicazioni nella Fisica delle Alte Energie, Fisica Nucleare, Astrofisica, Fisica Medica ed Elettronica di Potenza EU Project E2PHEST2US’ Thermionic Stage Load Radiation Absorber Collector Rload Rload Thermoelectric Stage Load p Under Vacuum Viareggio – CAEN June 24th, 2011 n Concentrated Solar Radiation (400 – 1000 suns) p n p n Thermionic Emitter Inter-electrode Space (<1 mm) Development of: T •A radiation absorber made of ceramic materials able to work stably at high temperature (700 1000 °C) TR (700-1000 °C) TE TC (250-400 °C) •A thermionic conversion stage with CVD diamond as the active material TTE •A thermoelectric conversion stage constituted by high Seebeck coefficient materials TAmb •Maximum theoretical efficiency ≈ 30% Final Thermal Stage Thermoelectric Stage z *For details, http://www.ephestus.eu Elettronica basata sul Diamante: Applicazioni nella Fisica delle Alte Energie, Fisica Nucleare, Astrofisica, Fisica Medica ed Elettronica di Potenza CVD Diamond based Active Devices Viareggio – CAEN June 24th, 2011 Thanks for the attention S2DEL DiaC2Lab S2DEL (Diamond & Carbon Compounds Lab) Solid State and Diamond Electronics Lab IMIP - CNR - Montelibretti (RM) Università degli Studi “Roma Tre” Elettronica basata sul Diamante: Applicazioni nella Fisica delle Alte Energie, Fisica Nucleare, Astrofisica, Fisica Medica ed Elettronica di Potenza Viareggio – CAEN June 24th, 2011 Elettronica basata sul Diamante: Applicazioni nella Fisica delle Alte Energie, Fisica Nucleare, Astrofisica, Fisica Medica ed Elettronica di Potenza Alternative Technology in Concentrating Systems •Multi-junction Photovoltaic Cells Nominal Conversion Efficiency of 30% Compactness No mechanical parts in movement Viareggio – CAEN June 24th, 2011 •Highly Expensive •Mandatory Need of Cooling (Conversion Efficiency Exponentially Decreases with Temperature) •Illumination Local Inhomogeneities Causes Output Bottlenecks •Production Dependent on Semiconductor Industry (Few Large-Scale World Suppliers) •Thermodynamic Conversion by Heat Engines (Stirling, Rankine) •Nominal Conversion Efficiency of 35% at High Temperatures (> 600 °C) •Not Compact System •Mechanical Parts in Movement (Degradation with Operative Time) •Economically Reasonable for Large Plants (> 10 kWe) Elettronica basata sul Diamante: Applicazioni nella Fisica delle Alte Energie, Fisica Nucleare, Astrofisica, Fisica Medica ed Elettronica di Potenza