Radiation Effects In Silicon Carbide Sic Micro Nanoelectromechanical Systems M Nems

Download or read book Radiation Effects in Silicon Carbide (SiC) Micro/Nanoelectromechanical Systems (M/NEMS) written by Hailong Chen and published by . This book was released on 2020 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radiation is of great importance in both fundamental science (e.g., understanding black holes, exploring the time evolution and the origin of the universe) and technological applications (e.g., diagnosing and treating diseases in medicine, and producing electricity at nuclear plant). Among all the radiation studies, radiation in semiconductor materials attracts the most attention in the information era with numerous semiconductor devices operating in space and on earth. Although silicon (Si) still dominates the semiconductor industry, a number of wide bandgap (WBG) semiconductors have demonstrated advantages in harsh environment applications. Among them, silicon carbide (SiC), with a family of polytypes and excellent properties such as wide bandgap (2.3-3.2 eV), high displacement energies (20-35 eV), excellent elastic modulus (~200-700 GPa) and outstanding thermal conductivity (~500 W m-1K-1), has shown great potential for high temperature, high power, and radiation resistant applications. A quite large body of work has been performed during recent decades to understand the radiation effects in the SiC electronic devices, such as field effect transistors (FETs), bipolar junction transistors (BJTs), and diodes. Meantime, while micro/nanoelectromechanical systems (M/NEMS) have gained tremendous advancements and made great impact on many important applications including inertial sensing (e.g., gyroscopes, accelerators), radio-frequency (RF) signal processing and communication, radiation study in M/NEMS has been quite limited, especially for those based on beyond-Si materials. This dissertation makes an initial thrust toward investigating radiation effects in SiC M/NEMS. First, we develop an innovative 3D integrated MEMS platform, by exploiting a scheme consisting of an array of vertically stacked SiC thin diaphragms (and Si ones for comparison). This integrated design and configuration not only scientifically enables probing different radiation effects (with clear reference and control samples) in a 3D fashion, but also economically evades very expensive, repetitive tests on individual devices. Further, we demonstrate cantilever-shaped 3C-SiC multimode MEMS resonators for real-time detection of ultraviolet (UV) radiation. In parallel, we have also developed Si counterparts of the SiC devices to help elucidate how SiC behaves differently from Si for radiation sensing and detecting. Finally, we explore the displacement and ionizing irradiation effects in SiC NEMS switching devices to gain comprehensive and in-depth understanding of the science behind the radiation effects in nanoscale structures made of thin SiC on SiO2. The investigation of NEMS switches before, during, and after proton and X-ray irradiation reveals how energetic particles cause threshold voltage modification, due to the dislocation damage in SiC crystal and how ionizing effects may affect the performance of these nanoscale devices.