0.2-MU-M GATE PSEUDOMORPHIC INGAAS/ALGAAS INVERTED HEMTS

We developed 0.2-mu-m gate pseudomorphic InGaAs/AlGaAs inverted HEMTs (I-HEMTs) both analytically and experimentally. Charge control analysis in a pseudomorphic I-HEMT and a simple GaAs/AlGaAs 1-HEMT indicates that the pseudomorphic structure accomplishes higher gm and fT because of its higher concentration and better confinement of a two dimensional electron gas (2DEG). We fabricated the two types of 0.2-mu-m gate I-HEMTs. Excellent device performances, i.e., fT = 106.6GHz and tau-pd = 6.6ps/gate are obtained in the pseudomorphic I-HEMT, which are better than those in the simple I-HEMT. The experimental results are qualitatively in good agreement with the calculated results.