Thin film deposition
Pulsed laser deposition
To grow high-quality thin film oxide films we utilize a pulsed laser deposition (PLD) system. This vacuum system consists of a load-lock and a deposition chamber with a base pressure of 1 x 10-8 mbar. In the main chamber, three targets are mounted on a carousel holder allowing for the sequential growth of different materials. The substrate is heated by a series of quartz lamps and this enables deposition temperature control up to 800°C. The load-lock is equipped with an evaporator for in-situ growth of metallic electrodes.
Currently, the PLD system is used for the ACTIVE-BAR project. In this project, tunnel junctions with active barrier materials including ferroelectric, ferrimagnetic, and multiferroic oxides are studied. Further information can be found in the PLD pages.
The NanoSpin Laboratory is equipped with a new magnetron sputtering system for the growth of thin films and multilayer heterostructures. This automated system consists of 9 magnetron guns and a holder for 14 substrates. Together with a heating capability of up to 650°C, this enables the growth of a large variety of materials including magnetic films and functional oxides. Moreover, it contains a metal shadow masking system with a capacity of 14 different masks for in-situ patterning and a wedge tool for the growth of films with a well-defined thickness gradient.
Several e-beam evaporators are available at Micronova. These systems are utilized for the deposition of metallic multilayers and magnetic thin films.
Nanostructuring and device fabrication
To structure our films and multilayers we use the cleanroom facility at Micronova, the leading research center for micro- and nanotechnology in Finland. Micronova’s modern facilities include a 2600 m2 cleanroom with processing lines for silicon BiCMOS, MEMS, III-V optoelectronics and thin film devices. Key instruments that are utilized in our research projects include:
- Carl Zeiss Supra 40: Scanning electron microscope with Raith softwarefor high-resolution e-beam lithography.
- FEI Helios Nanolab Dual Beam: Focused ion beam and electron beam systemfor high-resolution imaging and nanoscale patterning.
- Mask aligners, spinners, hotplates/ovens, reactive ion etcher (RIE), and wet processing equipment for photolithography.
- E-beam evaporators and a plasma-enhanced chemical vapor deposition (PECVD) Oxford 80+ system.
Thin film and device characterization
For high-resolution structural characterization of thin films, multilayers, and nanostructures we utilize the state-of-the-art facilities of the new Nanomicroscopy Center. This center is also located in the Nano Building. Key instruments that are used in our research projects include:
- JEOL JSM-7500F Scanning Electron Microscope
- JEOL JEM-2200FS double Cs corrected Transmission Electron Microscope
Also available are two scanning probe microscopes (SPM), namely a Veeco Dimension 5000 SPM and a Veeco MultiMode SPM. These instruments provide a powerful platform for atomic force microscopy (AFM), magnetic force microscopy (MFM), piezo force microscopy (PFM), scanning tunneling microscopy (STM), and conductive AFM.
Besides MFM, several other complementary techniques are available for detailed analysis of the magnetic and ferroelectric properties of thin films and nanostructures.