Instrumentation at Nanostructure Physics, KTH
Rayuta Yagi, Anders Liljeborg, Jochen Walter, Mattias Urech, David HavilandPeter Ågren, Jan Johansson, Jonas Rundqvist, Karin Andersson, Silvia Corlevi
(not shown – Vladislav Korenivski)
Our Realm in Experimental Physics
• Low energies (eV)
• Low Temperatures (20 mK)
• Small signals (nV, fA)
• Single charge (2e=1.3x10-18 C)
• Single flux quanta (0=2.06x10-15 W m2)
• Small dimensions (10 – 100 nm)
Typical Sample and Measurement
-30
-20
-10
0
10
20
30
-400 -200 0 200 400
I (pA)
V (µV)
B = 57 G
B = 66 G
B = 70 G
T=50mK
KTH Nano-Fab Lab
•Nano and micro scale fabrication,imaging and metrology•Joint laboratory facility, broad user spectrum•Graduate students are users•Low overhead costs, flexible research environment
Philosophy
K. A. Wallenberg Foundation
9 Msek, 1998•Electron-beam lithography•Plasma RIE•Wire bonder•clean benches, spinner, microscope, etc.
10 Msek , 2001•Atomic Force Microscope•Plasma RIE•Surface profilometer•photo lithography•clean benches
Low Cost (semi) clean room environment
E-beam lithography
Surface Profilometer
Atomic Force Microscope
Vacuum Deposition
System
Laminar flow benches(spinner, development)
Wet bench, hood
Light Microscope
Phase 2 Instruments – Phase 1 Instruments
Wire Bonder
Photo Lithography
Reactive IonEtcher(s)
Fluorescence MicroscopeCooled CCD camera
Low cost clean (enough) environment500 – 2000 particles per cubic foot
Ventilated clean air hoodsparticle count < 1/ft.3 after 2 minutes
Electron beam lithography•Versatile research tool•Beam writing and SEM capability, 6 inch laser stage.•High resolution (slow, nano features) and Low Resolution (fast, micro structure)
RaithTurnkey 150
Thickness measurement
0.1 Å vertical resolution0.5 m horizontalLow force (ca. N?)
Scanning Probe Microscope
Nanoscope IV Multi-mode: •AFM (air, liquid)•STM (air)•MFM, ESFM etc.•Image surface•Force measurement
spin dependant transport in nano-scale junctions(Nanostructure Physics, KTH)
-400 -200 0 200 400
0
5
10
Left junction Right junction
MR (%)
Field (Oe)
Two closely spacedCo/AlOx/Co tunnel junctions
Room TemperatureMagneto-resistance (MR)
Superconducting nano-circuits as quantum bits(Nanostructure Physics, KTH; Quantum Field Theory, SU)
GateSQUID
SETelectrometerAl Tunnel
junction
Aulead
Nanostructured ferroelectrics for linear and nonlinear optics(Laser physics and quantum optics, KTH)
Photonic Bandgap Structures
ion-exchanged gratings in KTP = 800 nm, depth > 200 m • aspect ratio > 500:1• L= 2 mm, w=1mm
used as passive narrow band filters
Active devices – electrically addressable filters
sub-micron periodically domain inverted
structures fabricated for first time• = 720 nm, depth 500 m • aspect ratio > 500:1• L=1 mm, W= 1 mm
Top view
Bottomview
Nano fabricated X-ray lenses(Biomedical and X-ray Physics, KTH)
Diffractive Optics -- Zone PlateCompact X-ray Microscope
Nano-patterned surfaces for cell growth studies(Polymer Chemistry, KTH; Nanostructure Physics, KTH)
Optical microscope imageSine-wave grooves in PMMA
Electron-microscope image
Protein A cys - biotin - neutravidin fluoro spheres self assemble on nanometer scale pattern(Nanostructure physics, KTH, Protein Engineering, KTH)
Neutravidin
40 nm fluorescent sphere
S-H PEG 50 Å
Au 2000 Å
10 m
Measurement Equipment
• Low Temperatures (down to 20 mk)
• High Frequency (up to 2 GHz)
• Small Signals (fA, nV, Lockin, low noise AF)
• High Impedence (> G Ohm)
Low Temperature
Dilution Refrigerator (Tmin 250 mK)
He3 Crostat (Tmin 250 mK)
Low Frequency techniques
• Lockin Amplifier• Low noise preamplifiers
– Home-made based on BB OPA111, high source impedence, high CMR, symmetric baising circuit.
– Standford 560 (voltage) and 570 (current) preamps
• Noise Matching – match source impedance to input impedence of preamp at given frequency for minimum noise
Network Analyizer up to 2GHz
Reflected and transmitted signal, Amplitude and phase
•Impedance of high inductance microstrips•Permiability of magnetic films•Characterize transmission lines, couplings, filters
No picture - Digital Sampling Oscilloscope with TDR module (ps resolution)
Vibrating Sample Magnetometer
M vs. H of this magnetic filmsAlso “loop tracer”, real time rotation in plane of film
Magneto-optical Kerr Effect
Future HF Techniques
• ns or sub-ns rise time pulses
• Broadband cabling in to cryostat
• CW generator greater than 2 GHz
• AWF generator
• Pulsed RF
• Field calculations around microstrips
• Tricks …. opto-electric? ……