Electron wave diffraction by semiconductor gratings: Rigorous analysis and design parameters

An exact rigorous coupled-wave analysis has been developed to model ballistic electron wave diffraction by gratings with periodic effective mass and/or potential energy variations. Design expressions have been derived to calculate diffracted angles, to identify evanescent orders, and to identify the Bragg condition. Design expressions for Bragg regime (up to 100% diffraction efficiency in a single order) and Raman–Nath regime (high diffraction efficiency divided among multiple orders) diffraction are presented along with example Ga1−xAlxAs grating designs. Design procedures for ballistic electron switches, multiplexers, spectrometers, and electron waveguide couplers are described.