PSEUDOMORPHIC GAAS/GAINAS PULSE-DOPED MESFETS GROWN BY ORGANOMETALLIC VAPOR-PHASE EPITAXY

Pseudomorphic pulse-doped (PPD) MESFETs with a Si-doped GaInAs active layer have been successfully developed for low noise application. The devices with 0.35-mu-m gate-length exhibited as good linearity as pulse-doped MESFETs with a Si-doped GaAs active layer. The maximum transconductance (gm(max)) and the transconductance (gm) at low drain current (congruent-to 0.2 Idss) were 380 mS/mm and 250 mS/mm, respectively. These values are 10 approximately 20% higher than those of the pulse-doped MESFETs. The minimum noise figure (Fmin) of the PPD-MESFETs is 0.74dB at 12GHz for 0.35-mu-m devices, which is 0.1dB lower than that of the pulse-doped MESFETs.