Flicker Noise of AlGaN ∕ GaN Metal-Oxide-Semiconductor Heterostructure Field-Effect Transistor with a Photo-CVD SiO2 Layer

Abstract

The effects of drain-source distance and applied voltage on low-frequency noise behavior of metal-oxide-semiconductor heterostructure field-effect-transistors incorporated with a photochemical vapor deposited (photo-CVD) gate oxide layer were investigated. According to our studies, the normalized noise power density is inversely proportional to when devices are biased in the linear region. However, the drain-source distance alone exerts little influence on low-frequency noise in the saturation and cutoff regions. Furthermore, the noise characteristics and the Γ value were affected by the interface state distribution in the energy bandgap as the gate bias was varied. The normalized noise power density determined is independent of the drain-source voltage in the linear region, but it exhibits an enhancement in the saturation region in response to an increase in the drain-source voltage. However, the noise power density then becomes constant when devices are biased in the cutoff region.