Analyzing the Effects of Barrier Thickness on the Performance of GaN HEMTs
摘要
This study investigates the effect of barrier-layer (BL) thickness on the performance of GaN high electron mobility transistors (HEMTs). Direct current (DC) characteristics, intrinsic parameters, and noise performance have been analyzed for devices with BL thicknesses of 16 nm, 19 nm, 22 nm, and 25 nm. It was found that thicker BLs provide better current handling, with a 25 nm BL device showing the highest drain current (Ids) of 800 mA/mm. However, thinner BLs give better gate control, as demonstrated by the higher transconductance (gm), with a 16 nm BL device having the highest gm of 240 mS/mm. Intrinsic parameters have shown that with thinner BLs, gate capacitance (Cgs) is higher, with a 16 nm BL device measuring 1.2 pF/mm. Conversely, with thicker BLs, resistance is higher (Rgs, Rgd, and Rds). Noise analysis showed that the minimum noise figure (NFmin) for a 16 nm BL device was the lowest (0.8 dB at 10 GHz), but a 25 nm BL device showed better high-power performance due to minimum parasitic losses. These trade-offs make BL thickness selection an essential concern for optimizing GaN HEMTs for high-frequency and power applications.