Influence of the ZrO2 gate dielectric layer on polarization coulomb field scattering in InAlN/GaN metal–insulator–semiconductor high-electron -mobility transistors. (November 2022) - Jiang, Guangyuan
Abstract: An InAlN/GaN MIS-HEMT with ZrO2 gate dielectric layer and a Schottky-gate InAlN/GaN HEMT were fabricated. Subsequently, the influence of ZrO2 gate dielectric layer on polarization Coulomb field (PCF) scattering in InAlN/GaN MIS-HEMT was studied. Compared with InAlN/GaN HEMT, the ZrO2 gate dielectric layer in InAlN/GaN MIS-HEMT results in fewer additional polarization charge and higher two-dimensional electron gas density at the same gate-source voltage (VGS ) conditions. Also, we established that both of these factors weaken PCF scattering intensity. However, the InAlN/GaN MIS-HEMT has a larger gate swing. Therefore, there is a smaller VGS was applied during regular operation of device. When the VGS is small, PCF scattering is the strongest scattering and play non-negligible impact in the size of total electron mobility. This study provides a new theoretical foundation for further enhancing the performance of InAlN/GaN MIS-HEMTs. Highlights: The influence of the ZrO2 gate dielectric layer on PCF scattering in InAlN/GaN MIS-HEMTs was determined. The ZrO2 layer leads to fewer Δ ρ G and higher n 2 D E G at the same gate bias conditions, both of these factors weaken PCF scattering intensity. When the gate bias is small, PCF scattering plays a dominant role in the magnitude of the total electron mobility. The results of this study have providing a new theoretical basis for further enhancing performance of InAlN/GaN MIS-HEMTs.