Budapest University of Technology and Economics Department of Electron Devices eet.bme.hu Electronics, microelectronics, nanoelectronics, … Part II Mizsei, János

© BME Department of Electron Devices, eet.bme.hu February 6, 2013

© BME Department of Electron Devices, eet.bme.hu February 6, 2013

© BME Department of Electron Devices, eet.bme.hu February 6, 2013

© BME Department of Electron Devices, eet.bme.hu February 6, 2013 Outline nanoscale effects dimensions atomic scales: different transport mechanisms (thermal, electrical, mechanical) technology at nanoscale lithography by nanoballs nanoimprint Langmuir-Blodgett technology MBE – molecular beam epitaxy FIB – focused ion beam AFM, STM processes nanoscale devices QWFET single electron devices nanotubes nanorelays organic molecular integrated circuits vacuum-electronics spintronics kvantum-computing oxide electronics thermal computing

© BME Department of Electron Devices, eet.bme.hu Nanoscale effects February 6, 2013 density of states for dimension objects tunnelling surface/interface scattering ballistic transport

© BME Department of Electron Devices, eet.bme.hu Technologies at nanoscale February 6, 2013 lithography by nanoballs nanoimprint Langmuir-Blodgett technology MBE – molecular beam epitaxy FIB – focused ion beam AFM, STM processes

© BME Department of Electron Devices, eet.bme.hu Lithography by nanoballs

© BME Department of Electron Devices, eet.bme.hu Nanoimprint February 6, 2013

© BME Department of Electron Devices, eet.bme.hu Nanoimprint

© BME Department of Electron Devices, eet.bme.hu Langmuir-Blodgett technology February 6, 2013 for molecular monolayer

© BME Department of Electron Devices, eet.bme.hu MBE – molecular beam epitaxy February 6, 2013 Computer controlled evaporation (PVD)

© BME Department of Electron Devices, eet.bme.hu MBE – molecular beam epitaxy

© BME Department of Electron Devices, eet.bme.hu FIB – focused ion beam

© BME Department of Electron Devices, eet.bme.hu FIB – focused ion beam Applications of FIB: cross-sectional imaging through semiconductor devices (or any layered structure) modification of the electrical routing on semiconductor devices failure analysis preparation for physico-chemical analysis preparation of specimens for transmission electron microscopy (TEM) or other analysis micro-machining mask repair

© BME Department of Electron Devices, eet.bme.hu FIB – focused ion beam FIB drilled nanohole for thermal nanoswitch with Pt overlayer

© BME Department of Electron Devices, eet.bme.hu AFM processes February 6, 2013 Hotplate for AFM excited agglomeration and peel off Nanostructures by AFM tip excitation of hot (120 o C) silver nanolayers

© BME Department of Electron Devices, eet.bme.hu AFM processes February 6, 2013 Quantum corall by AFM tip (Fe on Cu surface)

© BME Department of Electron Devices, eet.bme.hu AFM processes: anodic oxidation by AFM tip February 6, 2013

© BME Department of Electron Devices, eet.bme.hu Microscopic charges on SiO 2 surfaces 100 nm native oxide oxide Si: P type,, 10 ohmcm

© BME Department of Electron Devices, eet.bme.hu Charging process: (AFM, “conducting wire”) Measuring process: (Kelvin electric force microscopy) Low resolution, compared to the charging process !

© BME Department of Electron Devices, eet.bme.hu 11:30:29 AM Fri Aug :11:07 PM Thu Aug V V

© BME Department of Electron Devices, eet.bme.hu 04:11:07 PM Thu Aug :30:29 AM Fri Aug V V Only after 300 C heat treatment !

© BME Department of Electron Devices, eet.bme.hu Microscopic charge on the SiO 2 surface Extremely high and inhomogeneous electric field: V/m

© BME Department of Electron Devices, eet.bme.hu Nanoscale devices February 6, 2013 QWFET single electron devices nanotubes nanorelays organic molecular integrated circuits vacuum-electronics spintronics oxide electronics thermal computing

© BME Department of Electron Devices, eet.bme.hu QWFET – quantum well fet low bandgap enables lower supply voltage higher bangap substrate helps to keep electrons in the channel higher mobility results in higher current Schottky-barrier type (depletion) device

© BME Department of Electron Devices, eet.bme.hu QWFET Problematic point: compound semiconductor in Si based technology

© BME Department of Electron Devices, eet.bme.hu Advantages of QWFET higher speed at lower power dissipation

© BME Department of Electron Devices, eet.bme.hu Single electron transistor - SET

© BME Department of Electron Devices, eet.bme.hu Fabrication of SET by STM tip anodisation

© BME Department of Electron Devices, eet.bme.hu Single electron devices: charge-memory SET read-out February 6, nm head- surface distance ~10 nm grain size ~10 Terabit/inch 2

© BME Department of Electron Devices, eet.bme.hu Carbon diamond graphite February 6, 2013

© BME Department of Electron Devices, eet.bme.hu Graphene, carbon nanotubes

© BME Department of Electron Devices, eet.bme.hu Carbon nanotubes as quantum wires density of states depending of chirality

© BME Department of Electron Devices, eet.bme.hu Carbon nanotube devices: CNT

© BME Department of Electron Devices, eet.bme.hu Micro-, and nanorelays Nanorelays nanorelays: instable mechanical movement, stick down

© BME Department of Electron Devices, eet.bme.hu Atom relay transistor (ART) Molecular single electron switching transistor (MOSES)

© BME Department of Electron Devices, eet.bme.hu Organic molecular integrated circuits

© BME Department of Electron Devices, eet.bme.hu Organic molecular integrated circuits ~100 nm 2

© BME Department of Electron Devices, eet.bme.hu Organic molecular integrated circuits Problems with the organic molecular ICs: technology (it has not been realised until now) metal contacts and wires (atomic contact) chemical instability slow operation depending on number of electrons/bit ratio

© BME Department of Electron Devices, eet.bme.hu Vacuum-electronics: nanosised „Vacuum tube” Vertical field emission: Lateral field emission: MOSFET- like gated devices

© BME Department of Electron Devices, eet.bme.hu Field emission by gate control

© BME Department of Electron Devices, eet.bme.hu Technology resist plasma treatment and reflow

© BME Department of Electron Devices, eet.bme.hu Characteristics of the nanosised „Vacuum tube”

© BME Department of Electron Devices, eet.bme.hu Spintronics, Stern-Gerlach experiment February 6, 2013

© BME Department of Electron Devices, eet.bme.hu Spin: Einstein–de Haas effect Switch on and off with the resonance frequency of the suspended mass

© BME Department of Electron Devices, eet.bme.hu GMR - giant magnetoresistance February 6, 2013 Low resistancehigh resistance

© BME Department of Electron Devices, eet.bme.hu Spin- valve MRAM

© BME Department of Electron Devices, eet.bme.hu Spin- transistor on February 6, 2013

© BME Department of Electron Devices, eet.bme.hu Spin- transistor off February 6, 2013

© BME Department of Electron Devices, eet.bme.hu Quantum dot (QD) logika Inverter

© BME Department of Electron Devices, eet.bme.hu Oxide electronics February 6, 2013

© BME Department of Electron Devices, eet.bme.hu

© BME Department of Electron Devices, eet.bme.hu 54 S. D. Ha and S. Ramanathan J. Appl. Phys. 110, (2011 )

© BME Department of Electron Devices, eet.bme.hu

© BME Department of Electron Devices, eet.bme.hu (A) In high resistance state, there is a lack of oxygen vacancies at the interface. Carriers must overcome Schottky barrier to contribute to current. (B) In low resistance state, oxygen vacancies accumulate at the interface, reducing depletion width such that tunneling is possible Oxygen vacancy drift bipolar switching mechanism for representative n-type oxide

© BME Department of Electron Devices, eet.bme.hu Switchable Pt/TiO x /Pt rectifier February 6, 2013 Opposite polarity voltage pulses control location of oxygen vacancies, which determines which contact is rectifying and which is Ohmic

© BME Department of Electron Devices, eet.bme.hu Experimental demonstration of spike- timing dependent plasticity (STDP) in Pt/Cu 2 O/W device Appl. Phys. A, S.-J. Choi, G.-B. Kim, K. Lee, K.-H. Kim, W.-Y. Yang, S. Cho, H.-J. Bae, D.-S. Seo, S.-I. Kim, and K.-J. Lee, Synaptic behaviors of a single metal–oxide–metal resistive device, 102, 1019, 2011 (A) I-V curves of MIM device showing bipolar resistive switching. (B) For  t>0 (pre-synaptic pulse fires before post-synaptic pulse), the synaptic weight increases, while for  t<0, the synaptic weight decreases, in accordance with STDP.

© BME Department of Electron Devices, eet.bme.hu

© BME Department of Electron Devices, eet.bme.hu „Nothing beats scaled silicon but nanotechnology can complement”

© BME Department of Electron Devices, eet.bme.hu Ethical issues concerning the nanotechnology -„nano” is a good idea and a good word to get money from the government or from the EU -many nanoobject have not fully been tested, some of them could be dangerous for health (?) -self replicating nanomachines may live their own life -> catastrophe ? -…

© BME Department of Electron Devices, eet.bme.hu Problems with CMOS device limits (6 or even more interfaces) scale down: depletion layers, gate-tunnel current -> direct tunnel distance: 2 nm)

© BME Department of Electron Devices, eet.bme.hu Problems with the nano self-replicated machines

Budapest University of Technology and Economics Department of Electron Devices eet.bme.hu End of part II