The uniformly doped and the δ-doped In0.52Al0.48As/In0.6Ga0.4As metamorphic high-electron mobility transistors (MHEMTs) were fabricated, and the dc characteristics and the third-order intercept point (IP3) of these devices were measured and compared. Due to more uniform electron distribution in the quantum-well region, the uniformly doped MHEMT exhibits a flatter transconductance (Gm) versus drain-to-source current (IDS) curve and much better linearity with higher IP3 and higher IP3-to-Pdc ratio as compared to the δ-doped MHEMT, even though the δ-doped device exhibits higher peak transconductance. As a result, the uniformly doped MHEMT is more suitable for communication systems that require high linearity operation.
Published in:
Electron Device Letters, IEEE
(Volume:27
,
Issue:
7
)
Date of Publication: July 2006