应用于AlGaN/GaN HEMTs MMIC薄膜电阻的特性与可靠性

TaN和NiCr是AlGaN/GaN HEMTs微波集成电路中薄膜电阻最为常用的两种材料.文中对比了在SiC衬底上生长的这两种材料的薄膜电阻的可靠性.通过TaN和NiCr薄膜电阻的对比,发现TaN薄膜电阻的方块电阻(Rs)随着退火温度的上升而增大,然而NiCr薄膜电阻的Rs却出现相反的趋势.同时发现随着退火温度的上升TaN薄膜电阻的s.和接触电阻(Rc)的变化远远小于NiCr薄膜电阻的变化.在400℃退火及等离子刻蚀机的氧等离子暴露后,TaN薄膜电阻的Rs只下降了0.7Ω,大概2.56%,并且Rc上升了0.1Ω,大概6.6%.但是NiCr薄膜电阻的Rs.和Rc在不同的退火条件下经过氧等离子暴露后发生了很大的变化.因此,TaN薄膜电阻在氮气保护下经过400℃退火后在氧等离子暴露下更为稳定.

Characterization and Reliability of Thin Film Resistors for MMICs Application Based on AlGaN/GaN HEMTs

Tantalum nitride (TAN) and nichrome (NiCr) are the two most common materials used as thin film resistors (TFR) for monolithic microwave integrated circuits (MMIC) based on AlGaN/GaN high electron mobility transistors (HEMTs). In this study, we compare the reliability of the two materials used as TFRs on a semi-insulation 4H SiC substrate. Through the comparison between NiCr and TaN thin-film resistor materials, we find the square resistor (Rs) of TaN TFR increases as the annealing temperature increases. However, the R, of NiCr TFR shows the opposite trend. We also find the change of the TaN Rs and contacted resistor (Rc) is smaller than the NiCr. After O2 plasma exposure in RIE, the TaN Rs only decreases 0.7Ω, or about 2. 56% ,and Rc increases 0. 1Ω, or about 6. 6% , at an annealing temperature of 400℃. In contrast, the NiCr Rs and Rc show large changes at different annealing temperatures after O2 plasma exposure. In conclusion, TaN is more stable during plasma exposure after 400℃ annealing in N2 ambient.