| The dimensional scaling of microelectronics to increase the ability of central process unit (CPU) is facing fundamental and physical challenges. The integration of high-performance non-volatile memory as the local memory in CPU will have a transformative impact on mobile electronics and portable systems. This dissertation proposes replacing the static random-access memory (SRAM) which is currently used as the local cache memory in CPU with high-performance Flash-like non-volatile memory for the consideration of memory density and power consumption. I have fabricated, fully characterized and compared different kinds of Flash-like charge-trapping non-volatile memory devices, including high-k dielectric charge-trapping devices, multi-stack discrete memory devices and molecular memory devices. The devices containing redox-active molecules exhibit excellent Program/Erase (P/E) speed, good retention and excellent P/E endurance for more than 109 cycles. The charge storage in these molecule-containing memory devices is naturally derived from the intrinsic redox processes of the molecules under a voltage bias. This is very different with other charge storage mediums in which the charge is stored in the trap centers or as a carrier. The intrinsic redox properties and the naturally derived, stable molecular structure make this memory very robust and reliable. The second part of the dissertation will discuss my research on one of the most attractive emerging materials: topological insulators. I have used the nanowire growth method and self-alignment processes developed by us for the non-volatile memory to fabricate the topological insulator nanowire field-effect transistors. This work experimentally demonstrates that the conduction of bulk Bi2Se3 and surface gapless conduction are apparently separated; the current of these devices can be tuned to have large On/Off ratio and close-to-zero Off state; and the carrier transport on the surface is mainly affected by the Columbic scattering. We have also observed the anomalous Aharonov-Bohm oscillation in these topological insulator nanowire field-effect transistors, which leads to new understanding about the quantum phenomena in these materials. All the above findings will open up a suite of potential applications in nanoelectronics and spintronics. |
