PHOTOTHERMAL AND ELECTROREFLECTANCE IMAGES OF BIASED METAL-OXIDE-SEMICONDUCTOR FIELD-EFFECT TRANSISTORS - 6 DIFFERENT KINDS OF SUBSURFACE MICROSCOPY

Six different configurations for metal-oxide-semiconductor field-effec t-transistor reflectance microscopy are presented, each one revealing a particular contrast of the operating structure. These different imag es are obtained by interchanging the modulation of gate-source and dra in-source potentials, as well as by varying the probe beam intensity. Three main components were identified in the signal, their relative im portance depending on the experimental configuration: the electrorefle ctance component, the photoinjected carrier (probe-induced) component and the bias current (Joule effect) component. The high ability of the technique to detect defects in these structures is also demonstrated. (C) 1997 American Institute of Physics.