Spin Injection in Silicon

The conjunction of charge manipulation in the semiconductor with the electron spin could lead to a whole new era in information technology, called semiconductor spintronics. In a spinFET device the conventional source/drain contacts are replaced by ferromagnetic (FM) electrodes, injecting and detecting spin-polarized current in silicon. The main advantage of this approach is the merge of information processing and storage in one device, employing a magneto-current effect that depends on the relative magnetization of the injector and detector electrode. The use of silicon as a host material for spin polarized current features a big advantage: its outstanding spin lifetime. The so-called conductivity mismatch between the FM contact and silicon is identified as major obstacle for spin injection, where the diodes' resistance area product has to match a narrow resistance window. In the present work the structural, electrical and magnetic properties of ferromagnetic Schottky diodes and MgO-based tunneling diodes have been investigated, employing CoFe/NiFe, NiFe and CoFeB ferromagnetic electrodes, different silicon doping densities and different post-deposition annealing conditions.

Autorentext

Thomas Uhrmann was born in 1982 and studied mechatronics at the University of Applied Sciences in Regensburg. In 2006 he joined the Austrian Institute of Technology, Nano Systems Group, where he did his PhD thesis in close collaboration with the Vienna University of Technology.