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We investigate the influence of fin architecture on linearity characteristics of AlGaN/GaNFinFET. It is found that the FinFET with scaled fin dimensions exhibits much flatter G m characteristics than the one with long fins as well as planar HEMT. According to the comparative study, we provide direct proof that source resistance rather than tri-gate structure itself dominates the G m behavior. Furthermore, power measurements show that the optimized FinFET is capable of delivering a much higher output power density along with significant improvement in linearity characteristics than conventional planar HEMT. This study also highlights the importance of fin design in GaN-based FinFET for microwave power application, especially high-linearity applications.

Ultra-thin-body (UTB) In0.53Ga0.47As-on-insulator (In0.53Ga0.47As-OI) structures with thicknesses of 8 and 15 nm are realized by transferring epitaxially grown In0.53Ga0.47As layers to silicon substrates with 15-nmthick Al2O3 as a buried oxide by using the direct wafer bonding method. Back gate n-channel metal-oxidesemiconductor field-effect transistors (nMOSFETs) are fabricated by using these In0.53Ga0.47As-OI structures with excellent electrical characteristics. Positive bias temperature instability (PBTI) and hot carrier injection (HCI) characterizations are performed for the In0.53Ga0.47As-OI nMOSFETs. It is confirmed that the In0.53Ga0.47As-OI nMOSFETs with a thinner body thickness suffer from more severe degradations under both PBTI and HCI stresses. Moreover, the different evolutions of the threshold voltage and the saturation current of the UTB In0.53Ga0.47As-OI nMOSFETs may be due to the slow border traps.

Commercially available AlGaN/GaN high-electron-mobility transistors (HEMTs) are beginning to enter the public scene from a range of suppliers. Based on previous studies, commercial GaN-based electronics are expected to be tolerant to different types of irradiation in space. To test this assumption, we compared the characteristic electrical curves obtained at different X-ray irradiation doses for GaN HEMT devices manufactured by Infineon and Transphorm. The p-GaN-based device was found to be more robust with a stable threshold voltage, whereas the threshold voltage of the device with a metal-insulator-semiconductor gate was found to shift first in the negative and then the positive direction. This dynamic phenomenon is caused by the releasing and trapping effects of radiation-induced charges in the dielectric layer and at the interface of irradiated devices. As such, the p-GaN-gate-based GaN HEMT provides a promising solution for use as an electric source in space.

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