Title :
Fabrication and operation of a velocity modulation transistor
Author :
Webb, Kevin J. ; Cohen, Erwin B. ; Melloch, Michael R.
Author_Institution :
Sch. of Electr. & Comput. Eng., Purdue Univ., West Lafayette, IN, USA
fDate :
12/1/2001 12:00:00 AM
Abstract :
The velocity modulation transistor (VMT) has two channels with differing velocities. Small vertical distances between these channels can be achieved using epitaxial growth, opening the opportunity for higher speed than the high electron mobility transistor (HEMT). Experimental results from a VMT realized using the AlGaAs/GaAs system are given. The VMT channel carrier population as a function of input gate voltage is calculated for HEMTs and VMTs using a one-dimensional (1-D) numerical model. This supports a proposed equivalent circuit model for the VMT, which is used to compare VMT performance to that of HEMTs. A noise model for the VMT is developed, and this model suggests that HEMT-like noise is achievable with good carrier confinement. The dual gate, dual-channel VMT, while more complex than the HEMT, may be useful in applications such as analog-to-digital converters (ADCs) and microwave amplifiers
Keywords :
III-V semiconductors; aluminium compounds; carrier density; equivalent circuits; field effect transistor switches; gallium arsenide; microwave field effect transistors; semiconductor device models; semiconductor device noise; 1D numerical model; ADC comparator application; AlGaAs-GaAs; AlGaAs/GaAs system; HEMT-like noise; VMT performance; carrier confinement; channel carrier population; device fabrication; dual gate transistors; dual-channel transistors; epitaxial growth; equivalent circuit model; high electron mobility; input gate voltage; internal switching time; microwave amplifier application; microwave transistors; noise model; semiconductor heterojunctions; velocity modulation transistor; Carrier confinement; Circuit noise; Epitaxial growth; Equivalent circuits; Fabrication; Gallium arsenide; HEMTs; MODFETs; Numerical models; Voltage;
Journal_Title :
Electron Devices, IEEE Transactions on
