Electrical Spin-Injection into Silicon and Spin FET

摘要

In this seedling proposal funded by DARPA the project formed the PhD thesis of the graduate student Marc van VeenHuizen of Physics Dept (MIT), who successfully defended his PhD thesis in December 2009. He is now a research engineer at Intel Semiconductor Company. The aim of the project was to explore a tunneling emitter bipolar transistor as a possible spin injector into silicon, and we have succeeded in that goal. The transistor has a metallic emitter that as a spin-injector will be a ferromagnet. Spin-polarized electrons from the ferromagnet tunnel directly into the conduction band of the base of the transistor and are subsequently swept into the collector. The tunneling emitter bipolar transistor as a spin-injector allows for large spin-polarized currents and naturally overcomes the conductivity mismatch and Schottky barrier formation. In this work, the various aspects of the transistor were analyzed. The transfer of spin-polarization across the base-collector junction was simulated. The oxide MgO was considered as a tunnel barrier for the transistor and thoroughly investigated. Significant additional knowledge resulted in this project. Two journal articles have been published from this work in addition to two international conference presentations and a PhD thesis. Two more articles are under preparation.