Heterostructure field effect transistor with doping dipole in charge control layer

The heterostructure field effect transistors with a doping dipole layer obtained by planar p⁺⁺ and n⁺⁺ layers in charge control layer are proposed and fabricated in AlGaAs/GaAs. The dipole creates a large barrier between the channel and the gate, and this leads to a reduction of the forward biased gate current, a broad transconductance peak, a high maximum drain current, and no negative transconductance in enhancement-mode n-channel devices.