Properties of electromagnetic fields and effective permittivity excited by drifting plasma waves in semiconductor-insulator interface structure and equivalent trans-mission line technique for multi-layered structure

Abstract

Strong interests are recently emerging for development of solid-state devices operating in the so-called “terahertz gap” region for possible application in radio astronomy, industry and defense. To fill the THz gap by using conventional electron approach or transit time devices seems to be very difficult due to the limitation that comes from the carrier transit time where extremely small feature sizes are required. One way to overcome this limitation is to employ the traveling wave type approach in semiconductors like classical traveling wave tubes (TWTs) where no transit time limitation is imposed. In this paper, the analysis method to analyze the properties of drifting plasma waves in semiconductor-insulator structure based on the transverse magnetic (TM) mode analysis is presented. Two waves components (quasi-lamellar wave and quasi-solenoidal wave), electromagnetic fields (Ey , Ez and Hx ) and ω- and k-dependent effective permittivity are derived where these parameters are the main parameters to explain the interaction between propagating electromagnetic waves and drifting carrier plasma waves in semiconductor. A method to determine the surface impedances in semiconductor-insulator multi-layered structure using equivalent transmission line representation method is also presented since multi- layered structure is also a promising structure for fabricating such a so-called plasma wave device.