关键词: GaAs Ti/Pt/Au栅；耗尽型PHEMT；增强型PHEMT；微波单片集成电路；氢退化；耐氢能力

Abstract: The method of thickening SiN passivation layer on Ti/Pt/Au PHEMT Gate for hydrogen resistance improvement is submitted and verified to be effective by high temperature hydrogen experiments. When the SiN passivation layer on the Ti/Pt/Au gate of D-mode PHEMT is increased by 300nm from 150 nm, the tolerable hydrogen concentration and time can increase up to 30000×10-6 110 h (Ids keep on) from 14000×10-6 40 h (Ids began to decrease), which evidently greater than that of MMIC with 150 nm SiN on the gate. While the SiN passivation layer on the Ti/Pt/Au gate of E-mode PHEMT is increased to 600 nm, the tolerable hydrogen concentration and time can increase up to 20000×10-6 110 h (Ids is not decreased evidently), which gets to the practical use level.

Key words: GaAs Ti/Pt/Au Gate; D-Mode PHEMT; E-Mode PHEMT; MMIC; Hydrogen degradation; Hydrogen resistance