Design of Ballistic MOSFET for Operation at Terahertz Frequencies

The flow of information is expected to make a quantum leap with increasing speed of semiconductor devices. Among many transistors, FETs with ballistic transport stand out as the ones that can reach the terahertz operational frequencies. We present the design of the vertical ballistic MOSFET structure, capable to operate at 1THz. The source to drain distance in vertical direction is 400Å. The cross-section of the device (seen from the top) is rectangular with dimensions of 600Å by 100μm, which allows to run a total current of 10 – 15mA/μm normalized to the width of the channel. Two gates are positioned along the channel, at the opposite walls of vertical structure. The distance between the gates, i.e. width of the channel, is 600 Å. This design configuration demonstrates ability to operate at maximum frequency of about 1 THz. The current gain and S-parameters as well as some potential fabrication issues are discussed.