Mohammadjavad Mohammadzamani - Device and Simulation Laboratory,Department of ElectricalandComputerEngineering,University of Tehran,North Kargar Ave,Tehran,Iran
Morteza Fathipour

Electrical performance of AlGaN/InGaN pseudomorphic high electron mobility transistors(PHEMTs) are investigated using two-dimensional commercial numericalsimulator. Two PHEMT structures are studied, namely uniformly doped PHEMT(U-PHEMT) and PHEMT with double-delta doped layers(D-PHEMT). Simulation resultsindicate that delta-doped structure has superior performance than uniformly-doped structure which includes better carrier confinement properties and consequently reduced parasitic conduction which is manifested as higher transconductance andimproved drain current so that maximum drain current (ID,max) 1625 mA/mm and maximum transconductance(gm,max) 468 mS/mm are obtained for D-PHEMT while U-PHEMT displays maximum drain current (ID,max) 1300mA/mm and maximum transconductance(gm,max) 418 mS/mm. The small signal properties were also achieved with the current gain cut-off frequency (fT )of 46.25 GHz for D-PHEMT and 45GHz for UPHEMT.It’s found that D-PHEMT in addition to having higher ID,max and gm,max , also has an almost equal cut off frequency to the U-PHEMT

P-HEMT, HFET, Pseudomorphic HEMT, Delta-Doping, 2DEG