SURFACE ELECTRONIC STATES AT THE INHOMOGENEOUS INTERFACE SEMICONDUCTOR - DIELECTRIC

Abstract

The subject matter is the analysis processes and conditions for the generation (amplification) of electromagnetic oscillations in the submillimeter range by creating surface electronic states at an inhomogeneous interface between media, which is realized for structures such as metal – semiconductor – dielectric (M-S-D), where the localization sizes of surface states are within the range of approximately 10-4 cm. The aim is the possibility of conducting theoretical and experimental studies based on the proposed physical model for the emergence of surface electronic states at an inhomogeneous boundary of solid bodies, in conditions where the amplitude of the irregularities is much smaller than their period. Parameters of the lateral pulsed electromagnetic field, induced currents, and characteristics of semiconductor devices are established within which the mode of amplification of the intrinsic oscillations of the surface electron layer of the semiconductor structure is observed. The objectives are: the mechanisms of electron interaction at the interface between the conductor and dielectric, where the inhomogeneities are either random or periodic. As a result of this interaction, the electron concentration exponentially decreases with distance from the boundary. The methods used are: the methods of the theory of small perturbations (Rayleigh’s method) to determine the spectrum of surface electronic states under conditions where the amplitude of irregularities is much smaller than their period. The following results are obtained: A dispersion equation for the spatial harmonics of electrons at the inhomogeneous boundary of a conducting solid body is derived. By the method of successive approximations for the small parameter, its solution is determined, and it is shown that in limiting cases—longwavelength and short-wavelength—the localization sizes of electrons at the boundary have similar orders of magnitude for both periodic and random surfaces. Conclusion. The work provides quantitative estimates for the radiation energy values – the energy loss values of charged particle flows induced by an external electromagnetic field, leading to the excitation of surface electromagnetic oscillations in structures with boundary inhomogeneities in the presence of surface electronic states. The results show that the radiation energy for structures like metal – dielectric – semiconductor (M-S-D) lies in the range of  (10–7 – 10–8 ) Wt, which is detectable by modern microwave radiation receivers (approximately 10–10 Wt).