We report MOCVD-grown NpN InP/GaAsSb/InP abrupt double heterojunction bipol
ar transistors (DHBTs) with simultaneous values of f(T) and f(MAX) as high
as 300 GHz for J(C) = 410 kA/cm(2) at V-CE = 1.8 V The devices maintain out
standing dynamic performances over a wide range of biases including the sat
uration mode. In this material system the pi GaAsSb base conduction band ed
ge lies 0.10-0.15 eV above the InP collector conduction band, thus favoring
the use of nongraded base-collector designs without the current blocking e
ffect found in conventional InP/GaInAs-based DHBTs, The 2000 Angstrom InP c
ollector provides good breakdown voltages of BVCEO = 6 V and a small collec
tor signal delay of similar to0.23 ps. Thinner 1500 Angstrom collectors all
ow operation at still higher currents with f(T) > 200 GHz at J(C) = 650 kA/
cm(2).