Spin-Based Silicon and CMOS-Compatible Devices

Silicon, the main material of microelectronics, is attractive for extending the functionality of MOSFETs by using the electron spin. However, spin lifetime decay in the silicon-on-insulator transistor channel is a potential threat to spin-driven devices using silicon. We predict a giant enhancement of the electron spin lifetime in silicon thin films by applying uniaxial mechanical stress. The advantage of this proposal is that stress techniques are already routinely used in semiconductor industry to enhance the electron and hole mobility, respectively. The spin manipulation in silicon by purely electrical means is a challenge because of a relatively weak coupling of the electron spin to the electric field through an effective gate voltage dependent spin-orbit interaction. In contrast, the coupling between the spin orientation and charge current is much stronger in magnetic tunnel junctions. Magnetic random access memory (MRAM) built on magnetic tunnel junctions is CMOS-compatible and possesses all properties required for universal memory. We demonstrate a significant improvement of one of the critical MRAM characteristics, the switching time, by specially designing the recording layer. Finally, by using MRAM arrays we discuss a realization of an intrinsic non-volatile logic-inmemory architecture suitable for future low-power electronics.