| dc.description.abstract | As feature sizes for semiconductor devices approach atomic dimensions, memory architectures such as DRAM and flash, encounter performance limitations due to increased effects from leakage currents. In order to continue reduction in sizes of memories, a need arises for novel, nonvolatile memories that integrate high density and high access speeds with low power consumption. In recent years, one such type of nonvolatile memory, resistive memory, has received increased attention due to excellent performance of devices and its compatibility with CMOS processes. One way to implement such resistive memory is through a resistive switch, a two terminal, passive circuit element whose resistance state can be switched between two or multiple discrete states. These resistive switches are often collectively referred to as memristors (memory resistor). In this work, memristive devices are developed using titanium dioxide (TiO2)-porous silicon (PSi) nanocomposites. TiO2 is a well known memristive material which, when deposited into a PSi matrix, can be used to develop a micron-scale memristor device taking advantage of the numerous nanoscale PSi-TiO2 junctions that each form their own individual memristive element. The TiO2-PSi nanocomposites demonstrate pinched I-V hysteresis loops, the fingerprint of the memristor, and retention of resistance states for at least 2000 seconds. The observed variable resistance is attributed to migration of defects in the form of oxygen vacancies in the TiO2. Due to their relative large size and capability to support large currents, these TiO2-PSi nanocomposites may be best suited for high power applications and as analog memory components. | |
