Yüksek-K dielektrikli alan etkili nükleer radyasyon dedektörlerinin (NürFET) üretimi ve karakterizasyonu

The continuous development of a gate stack system and continually shrinking gate-dielectric thickness, have been necessitated by the requirement of higher gate capacitance in order to reduce excessive leakage currents in Metal- Oxide- Semiconductor Field- Effect transistors (MOSFETs). To obtain high gate capacitance and inhibit tunneling, relatively thick insulators with high dielectric constants (high-k) are needed in place of SiO2 gate dielectric in MOSFETs. In this thesis, the Hafnium Oxide (HfO2) and Erbium Oxide (Er2O3) have been used as two distinct high-k dielectrics as an alternative gate dielectric materials to conventional SiO2. Although several technological applications of the HfO2 and Er2O3 dielectrics are available in microelectronics, there still exists reliability problem for the usage of them in radiation environments. The detailed investigation should be performed for the realistic microelectronic applications of high- k materials. Hence, in the scope of this thesis, the MOSFETs with HfO2 and Er2O3 gate dielectrics have been fabricated and the possible device usage as a radiation sense materials for defense/space applications and/or radiation soft materials for possible dosimeter applications have been discussed. The device used for the dosimetric purposes, called Nuclear Radiation Sensing Field Effect Transistor (NürFET), is discrete p-channel MOSFET. In addition, the device failure mechanisms including the structural, morphological, electrochemical and electrical changing under radiation environment have also been discussed in details for understanding behaviors of the high- k based devices under radiation environment. The high-k device characteristics have been compared to experimentally fabricated and commercially available conventional devices with SiO2 gate.