Department of Micro- and Nanosciences (MNT) Aalto University - - PowerPoint PPT Presentation

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Department of Micro- and Nanosciences (MNT) Aalto University - - PowerPoint PPT Presentation

Mar 19, 2023 235 likes •428 views

Department of Micro- and Nanosciences (MNT) Aalto University Research groups (physics related) Micro and Quantum Nanotechnology Microelectronics Systems Prof. Harri Lipsanen Prof. Pekka Prof. Ilkka Tittonen - Nanomaterials and

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Department of Micro- and Nanosciences (MNT) Aalto University

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Research groups (physics related)

Nanotechnology

  • Prof. Harri Lipsanen
  • Nanomaterials and

nanofabrication

  • Graphene devices
  • Nanowires
  • X-ray detectors

Microelectronics

  • Prof. Pekka

Kuivalainen

  • Spintronics
  • Graphene device

modeling Micro and Quantum Systems

  • Prof. Ilkka Tittonen
  • Quantum optics
  • Thermoelectrics
  • Organic molecules
  • Ion trapping

Optoelectronics

  • Prof. Markku

Electron Physics

  • Dr. Hele Savin

Fiber Optics

  • Dr. Hanne Ludvigsen
  • Prof. Markku

Sopanen

  • III-N materials
  • Quantum dots
  • Plasmonics
  • Dr. Hele Savin
  • Photovoltaics
  • IC and MEMS
  • Defect engineering
  • Dr. Hanne Ludvigsen
  • Photonic crystal

fibers Photonics Open tenure track position (2012) Micro- and Nanoelectronics Open tenure track position (2012)

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Education & Publications

  • In average six D.Sc. degrees

produced annually

  • Aalto’s new cost model has

reduced department funding and personnel

  • Clear trend for higher

efficiency, year 2012 will be efficiency, year 2012 will be very good

  • Two new tenure track positions

will further increase the output

* 2012 values are numbers by 4/2012

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Impact of MNT groups

“We are doing things that have high impact on research, society and industry worldwide” Some examples:

– European Space Agency: X-ray detectors for the Mercury mission – Si material research has resulted in improvement of solar cells in PV industry and the models developed by us are in the use of wafer suppliers – LED manufacturer OptoGaN started in collaboration with MNT MOVPE researchers during 2004-2007, the company has now the largest LED lighting factory in Russia,

  • ther factory in Landshut, 7 MNT researchers have worked in the company

– Photoacoustic sensors used in a commercial product by Gasera, EU project – Photoacoustic sensors used in a commercial product by Gasera, EU project CUSTOM in this field – RF MEMS resonators in a product phase at VTI/Murata – Atomic layer deposition process & tool development with Beneq – Ultrathin x-ray windows developed with HS foils – Nordic NANORDSUN consortium for nanowire solar cells – DNA sensor, UV LEDs for water purification, LED lighting applications

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MNT has strong research activity in School's strategic focus areas

  • Micro- and nanotechnologies
  • Enabling technologies for research and applications
  • MNT is the largest Micronova clean room user and has crucial role

in maintaining and teaching the use of the tools and processes (so called main user activity)

  • Development of many unique clean room processes
  • Development of many unique clean room processes
  • Energy efficiency with nano
  • New LED solutions
  • Improvement of solar cells
  • Thermoelectric research
  • Artificial photosynthesis
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International aspects

  • 30 % of all researchers from abroad
  • International Master’s Programme on Micro- and Nanotechnology
  • Visiting professors: Mackillo Kira (Marburg, Germany), Babak Parviz

(University of Washington), Franco Kueppers (University of Arizona), Dimitri Firsov (St. Petersburg Polytechnic University), Alexander Pikhtin (LETI, St. Petersburg), Lu Wu and Guo Qi (Xinjiang, China)

  • Rapid increase of staff members working abroad in 2012
  • Increase in international funding
  • Increase in international funding

– Defects in silicon, funding from many foreign sources – EU projects: CUSTOM (photoacoustics), FUNPROB (nanowires), ENPI (Finland – Russia cross-border collaboration) – ERC starting grant in interview phase – EMRP REG on ion clocks – Invitation to Graphene Flagship in WP High-frequency electronics

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Effective surface passivation of non-reflecting black silicon

  • Reflectance below 1% obtained over wide spectral

range, both in sc- and mc-Si

  • Effective surface passivation method developed for the

first time → over millisecond lifetime demonstrated

  • Wide application range: solar cells, image sensors,

MEMS, IMS…

  • Demonstration in solar cells: work ongoing with

Fraunhofer ISE

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GaAs

nanowires (NWs) were grown on low-cost float type glass substrates (window glass) using MOVPE with Au nanoparticles as a catalyst

NWs on glass are of

high optical quality and have perfect zinc blende

GaAs nanowires grown on glass

SEM TEM

have perfect zinc blende structure with no structural defects (unlike in growth on silicon)

NWs on glass show

promising potential

  • f

solar cell integration on inexpensive large-area substrates

Glass substrate 470 0C NWs 580 0C NWs

  • V. Dhaka et al., “High Quality GaAs Nanowires Grown on Glass Substrates”,

Nano Letters 12 (2012) 1912

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Tailoring the waveguide properties in a back- end process

– Narrowing down slots in slot waveguides – Tuning waveguide dispersion

Integration of materials to Si waveguides

– Optimal nonlinearity: TiO2 or other materials – Decreased nonlinearity in waveguides – Composite materials: ALD nanolaminates

ALD (atomic layer deposition) in silicon nanophotonics

– Composite materials: ALD nanolaminates

T.Alasaarela et al., "Feature size reduction of silicon slot waveguides by partial filling using atomic layer deposition” Opt. Eng. 48 (2009) 080502

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Fiber Optical Sensors

Highly sensitive gas refractometer

  • I. Shavrin et al., Appl. Phys. Lett. 100 (2012)

I .Shavrin et al., Phys. Rev. B. (submitted 2012)

Real and imaginary part of the complex refractive index of acetylene as measured in first proof-of-principle experiments

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Light extraction in GaN LEDs

– Sapphire wet and dry etching

  • r GaN template patterning

– Light extraction enhanced by voids in GaN/sapphire interface – Dislocation termination by voids

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Plasmon enhanced emission in LEDs

  • Metal nanostructures patterned by

electron beam lithography, line period 200–500 nm, spacing 100 nm

  • Coupling between surface plasmons
  • f the metal and InGaN quantum well,

luminescence enhancement by 80%

  • Collaboration with prof. Joel Bellessa,

University of Lyon 1 University of Lyon 1

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Wireless contact lens display

LED microarray forms a pixel display that projects a virtual image into the retina through a micro Fresnel lens. The display is powered wirelessly by RF-power transfer.

Photos: Professor Babak A. Parviz, University of Washington A.R. Lingley, M. Ali, Y. Liao, R. Mirjalili, M. Klonner, M. Sopanen, S. Suihkonen,

  • T. Shen, B.P. Otis, H. Lipsanen and B.A. Parviz, A single-pixel wireless contact

lens display, J. Micromech. Microeng. 21 (2011) 125014

Joint work of Department of Micro- and Nanosciences (LED microarray fabrication) and University of Washington (contact lens integration) Research featured Nov. 2011 worldwide (BBC, New York Times, Fox news…)

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Functionalized and self-organized organic molecules for harvesting light energy with semiconductor quantum structures Goal: try to mimick nature!

Studies of molecular excitation, decay channels, stability, losses, efficiency, aggregation,

Molecular transitions Extraction of molecules, functionalization Epitaxial growth @ Micronova quantum wells Energetic matching Charge transfer

devices aggregation, various functionalization schemes, quantum effects

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. ) ) sin( (

||

∑

∞ −∞ = ⋅ ∝ m im m i

e r q J e

ϕ

θ

r q

Usually this is only a mathematical construction and the detection of individual OAM components is almost impossible Any optical plane wave consists of an infinite number of orbital angular momentum (OAM) modes:

Quantum optical effects in quantum rings

OAM components is almost impossible

  • In extremely small structures, only m=0

mode is effective.

  • In large structures, the effects of

different modes are mixed. Quantum rings are ideal for discrete detection of different m modes:

  • Size can be large enough to

allow m≠0 modes to interact

  • Volume is small enough to

provide fully quantized spectrum

Osmo Vänskä, Mackillo Kira, Ilkka Tittonen and Stephan Koch, "Indirect interband optical transitions in a semiconductor quantum ring with submicrometer dimensions”, Phys. Rev. B 84, 165317 (2011)

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<100> <111>

Ga+ FIB

FIB based 3D nanofabrication

Si

FIB implantation

Result: high precision 3D nanostructures. Fast method compared with milling!

54.7

+ Anisotropic wet etching

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SLIDE 17

17

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  • Research in Micronova
  • Unique large area fabrication on Cu surface by RTA-CVD
  • Full processing capabilities & device expertise
  • Devices & structures
  • Dual gate transistors for RF devices
  • Nonlinear electronic devices
  • Transparent nanolaminate conductors

Graphene nanoelectronics

Gate

  • Functional gas and bio sensors
  • Collaboration:
  • Graphene flagship 2013 (?): High-frequency Electronics
  • VTT Nanoelectronics (Micronova)
  • Nokia Research Center
  • Tokyo Institute of Technology & groups in China, Korea, Lithuania

50 µm

D S1 S2

Wonjae Kim, Pirjo Pasanen, Juha Riikonen and Harri Lipsanen, ”Nonlinear behavior of three-terminal graphene junctions at room temperature”, Nanotechnology 23 (2012) 115201