Joseph C. Woicik, Maitri P. Warusawithana, Cheng Cen, Charles R. Sleasman, Yulan Li, Jeffery Kluga, Lena F. Kourkoutis, Hao Li, Li-Peng Wang, Michael Bedzyk, David A. Muller, Long-Qing Chen, Jeremy Levy, Darrell G. Schlom
Silicon and silicon dioxide form what is arguably the most important technological interface. With the end of Moore s-law scaling for silicon fast approaching, alternatives to silicon dioxide are being pursued that may enable new device architectures and added functionality1-3. The high reactivity of silicon with many elements and their oxides4 and the tendency of a pristine silicon surface to rapidly form its own oxide, however, present formidable challenges to the integration of functional materials with silicon. Here we demonstrate, for the first time, ferroelectric functionality in intimate contact with silicon. Using piezo-force microscopy we observe ferroelectricity in ultra-thin, strained, SrTiO3 layers grown by oxide molecular-beam epitaxy in direct contact with silicon with no interfacial silicon dioxide. Stable ferroelectric nanodomains created in SiTiO3 and observed at temperatures as high as 400 K, may form the basis for a new class of ferroelectric memories5, bistable field-effect transistor devices6,7 and low power dissipation devices8 operating at room temperature.