The properties of aluminum-silicon-oxide (AlSiO) dielectric with varying silicon composition, grown on (000–1) N-polar GaN, were investigated in this paper. The refractive index, dielectric constant, and film density of AlSiO decreased with the increase of the silicon composition as indicated by ellipsometry, low-frequency capacitance-voltage (CV), and x-ray reflectivity (XRR) measurements, respectively. Negligible frequency dispersion in CV measurements and high-intensity XRR oscillations peaks were measured for all AlSiO samples with different silicon compositions, suggesting a high-quality N-polar GaN-AlSiO interface. The leakage current characteristics and flat-band voltage stability improved with the increase of the silicon composition from 20% to 46% and degraded for the sample that had a silicon composition of 73%. This study contributes to understanding the AlSiO dielectric performance for future use in the gate stack of N-polar GaN-based transistors.

中文翻译：

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用于N极GaN基器件的具有不同硅成分的AlSiO电介质的表征

本文研究了在（000-1）N极性GaN上生长的具有变化的硅组成的铝硅氧化物（AlSiO）电介质的特性。AlSiO的折射率，介电常数和膜密度随着硅组成的增加而降低，分别通过椭圆光度法，低频电容电压（CV）和X射线反射率（XRR）测量表明。对于具有不同硅成分的所有AlSiO样品，在CV测量中的频率色散和高强度XRR振荡峰均可以忽略不计，这表明了高质量的N极性GaN-AlSiO界面。随着硅组成从20％增加到46％，泄漏电流特性和平带电压稳定性得到改善，而硅组成为73％的样品的漏电流特性和平坦带电压稳定性下降。