Fabrication And Fundamentals Of Operation Of An Inalas/Ingaas Velocity Modulation Transistor

We report the design, fabrication, and characterization of an InP-based InAlAs/InGaAs velocity modulation transistor (VMT) based on the double-gate high electron mobility transistor topology. When electrons are transferred between two channels with different mobility, the drain current is modulated while keeping the total carrier density constant. For the fabrication of the transistor, the epitaxial growth has been optimized in order to accomplish the maximum mobility difference between the two active channels. DC characteristics of our VMT have been extracted and an ensemble Monte Carlo simulator is employed to study the microscopic behavior of the fabricated device. The numerical analysis of the carrier density and velocity variation with the gate bias in differential mode demonstrates the actual velocity modulation operation of the fabricated transistors.