Crystal thickness and extinction distance measurements by convergent beam electron diffraction fitting and application in quantitative TEM holography analysis on p-n junctions

Abstract

A modified model function is proposed to determine Si crystal thickness and extinction distance by fitting of the convergent-beam electron diffraction (CBED) intensity based on the dynamical diffraction and absorption theories. The previous fitting method employs two separate functions to simulate the elastic and inelastic parts of CBED intensity, while the present work uses a single model for the simulation. At an electron beam energy of 300 kV, the model demonstrates very fast and accurate thickness measurements ranging from 58 to 334 nm for the Si crystal. The minimum measurable thickness is around three times smaller compared with the conventional K–A plot method. From the fitting, the extinction distance of the Si (004) diffraction was determined to be 183.03 ± 2 nm, which is useful for the determination of the Si crystal structure factor. In conjunction with the transmission electron microscope holography technique, the authors study the electrostatic built-in potential across the p-n junction of the source and drain of a metal–oxide–semiconductor field effect transistor device.