UC Riverside

In the field of floating gate memory, also known as flash memory, silicon (Si) nanocrystals (NC) are one of the leading alternatives to traditional poly-Si floating gate memory because of their improved scalability, speed and simpler fabrication. In our research, Si NCs are grown on top of oxide covered carbon nanotubes (CNTs) by gas source molecular beam epitaxy for the purpose of making floating gate memory with the CNT as the field effect transistor (FET) channel. At certain conditions the NCs align on the apexes of the CNTs. These alignment properties are studied with relation to different growth conditions and sample parameters. Also FET and memory device characteristics are studied for devices based on this structure as well as the frequency response of devices that exhibit ambipolar properties. Another memory technology that has been attractive to replace flash due to its low power consumption and its stacking properties is resistive memory. Here ZnO NCs are used as the resistive switching material. The memory characteristics are studied with a conductive atomic force microscope contacting a single NC. Both of these technologies will be shown to have favorable properties compared to the current floating gate technology.