VTT combines physics, electronics and nanofabrication expertise to better
understand new phenomena in nanoscale structures and to find innovative, new
solutions. Our main areas of competence include superconducting electronics and
sensors, their readout electronics, and the applications of Josephson junction
devices and circuits, supported by expertise in device fabrication and
Low temperature quantum devices are used when ultimate performance is
required, as is often the case with security and with medical and space
applications. Recent areas of R&D concentration include MEG and low-field
MRI imaging, THz applications and multiplexing of transition edge sensors with
Suspended tunnel junctions and superconducting bridges for bolometer
- Well-established microfabrication process involving plasma etch-released
superconducting structures on wafer scale
- Multi-layer projection and contact lithography
- Superconductors Nb and NbN, as well as the use of novel insulator materials
and the integration of various resistive materials, including Mo (Tc ~ 0.9 K),
TiW (Tc < 50 mK), etc.
A Nb/Al-AlOx/Nb trilayer structure provides a robust technology for
Josephson junction-based devices and circuits
- I-line projection lithography with minimum junction size below 2 μm
- CMP planarized insulators for excellent step coverage
- The possible use of different insulator materials
- Nb Tc above 9 Kelvin
- Resistor material Mo (Tc ≈ 0.9 K) or TiW (Tc < 50 mK)
THz imaging with superconducting bolometer
VTT has developed a compact video-rated THz scanner for security
applications, based on superconducting hot-spot bolometers and a patented room
temperature readout technique.
AC current within suspended metal nanowires generates sound by heating the
surrounding air. Using a simple and low-cost microfabrication process,
nanothermoacoustics can be used efficiently, especially in ultrasonic
Printed electric coding
VTT has developed a non-contact near-field readout technique for printed
electric codes. These codes are invisible, inexpensive, low-cost and reliable.
The reader that we have developed is integrated on a single ASIC, and is
suitable for a wide variety of applications ranging from security and product
authentication to games and toys.
Eliminating MEMS readout noise with sensor biasing
Because of the impedance mismatch and 1/f noise of integrated electronics,
noise contribution of readout amplifier often dominates the MEMS sensor
resolution. But by biasing the sensor to the pull-in point (X = 0.33 D0), the
noise contribution of CMOS amplifier can be fully eliminated.