Radiation effects on wide bandgap semiconductor devices

Sammanfattning: Gallium nitride (GaN) based high-electron-mobility transistors (HEMTs) are used in a wide variety of areas, such as 5G, automotive, aeronautics/astronautics and sensing elds ranging from chemical, mechanical, biological to optical applications. Owing superior material properties, the GaN based HEMTs are especially useful in harsh operation environments e.g. in the combustion engine, exhaust, space, and medical instruments where the reliability and resilience are highly demanded. In this thesis the e ect of proton irradiation on the GaN HEMTs as well as the possible incorporation of them in biomedicine and diagnostics are investigated. The thesis includes mainly two parts: one is on theoretic background of GaN HEMTs, and another presents the experiment/simulation details of the devices before and after proton radiation. In the background section, the HEMTs function, manufacture technique and defect formation mechanism in the device under di erent proton radiation conditions are introduced. Then, the characterizations of the HEMT devices and related test structures before and after the proton radiation with dose range from 1011 to 1015 protons=cm2 are emphasized, as well as the comparison with simulation results obtained using SRIM/TRIM program. In addition, the biocompatibility of GaN devices and their biomedicine applications in proton radiation scenarios are also described and discussed in this thesis.