In this article, the authors present mobility and charge density tuning for metal organic chemical vapor deposition (MOCVD)-grown double delta-doped pseudomorphic high-electron-mobility transistors (PHEMTs). Good epitaxial wafers were obtained by MOCVD as indicated by uniform and abrupt interfaces seen in measurements taken using a transmission electron microscope and two pronounced Si-delta-doped peaks in the secondary ion mass spectrometry analysis. The I-Am-gate-length PHEMT device exhibited good dc performance with a threshold voltage of -1.34 V, a maximum drain current of 570 mA/mm, and a maximum transconductance of 279 mS/mm. From the dependences of mobility and charge density between the delta-doping level and spacer layer. thickness, most PHEMT design requirements in the ranges between 5750 and 7500 cm(2)/V S (for mobility) and 2.4 X 10(12) and 3.6 X 10(12) cm(-2) (for charge density) can be satisfied. (c) 2006 American Vacuum Society.