RADIATION EFFECTS AND LOW FREQUENCY NOISE OF MICROELECTRONIC DEVICES BASED ON TWO DIMENSIONAL MATERIALS
Metal oxide semiconductor field effect transistors (MOSFETs) are the building blocks of modern integrated circuits. The semiconductor industry needs to continue scaling the dimensions of transistors to keep up with the needs of the technology market. Two dimensional (2D) materials possess atomically thin body thickness while maintaining carrier mobility, making them promising channel materials for further channel length scaling. Radiation creates defects that impact the structure and electronic performance of materials. Determining the impact of these defects is important for developing 2D materials based devices for use in high radiation environments, such as space or nuclear reactors. In this work, the radiation responses of three 2D material systems (back gated graphene field effect transistors (FETs), dual gated MoS 2 FETs and MoS 2 tunneling junctions) have been investigated. Low frequency noise measurements are employed to provide insight into the change of defect energy distribution after total ionizing dose (TID) irradiation of these devices. Density functional theory (DFT) calculations are further applied to help identify the possible defect candidates responsible for the observed effects. This work has demonstrated the strong influence of H and O related defects on the performance, reliability, and TID responses of graphene transistors. Several defects and their energy levels have been identified in the MoS 2 system that affect the radiation response and low frequency noise of these structures. This study improves our current understanding of the radiation response and reliability of 2D materials, and provides insights into improving the properties of future electronic devices based on these materials.