Effects of an AlN passivation layer on the microstructure and electronic properties of AlGaN/GaN heterostructures

Interface characteristics of spin-on-dielectric SiOx-buffered passivation layers for AlGaN/GaN high electron mobility transistors

“…Shown in Table 2 are the Hall measurements for the epitaxial samples of three different passivation states. It is interesting to observe the significant increase of n s after the passivation regardless of passivation material, and this increase of carrier density after passivation was well found in other earlier studies [19,20]. However, the sample with Si 3 N 4 passivation produced a well-resolved reduction of the electron mobility compared to that of the sample with PHPS SOD passivation, which can be due to the higher-density interface states and trap charges possibly arising out of the plasma damage in the PECVD passivations.…”

The variation of temperature‐dependent carrier concentration and mobility in AlGaN/AlN/GaN heterostructure with SiN passivation

“…External biaxial tensile or compressive stress applied to a single hexagonal crystal heterostructure can change the carrier concentration as a result of the modification of piezoelectric polarization in the strained barrier layer .…”

“…Compared with the experimental data for the temperature‐dependent mobility and theoretically derived electron mobility based on Boltzmann transport equations gives information about crystal structure and the nature of the electrons. In AlGaN/GaN heterostructures, it was shown that polar optical phonon scattering and interface roughness scattering are the dominant scattering mechanisms at high and low temperatures, respectively .…”

Effect of residual H 2 O on epitaxial AlN film growth on 4H-SiC by alternating doses of TMA and NH 3

“…Because AlN and SiC have very similar lattice constants [2], thermal expansion coefficients, and atomic arrangements, the AlN film is widely used as a buffer layer for GaN epitaxial growth on SiC (0 0 0 1). Its wide bandgap and high dielectric constant also make AlN an ideal dielectric material on SiC for high power electronic devices, which are needed in radio frequency and high-speed communication, for the high quality interface [3][4][5]. It has been reported that device performance is strongly related to dislocations, so the device design mitigates the influence of material imperfections [6].…”