BROAD-BAND SPECTRAL OPERATION OF A ROTATING-COMPENSATOR ELLIPSOMETER

We show that a rotating-compensator ellipsometer (RCE) with a zero-ord er retarder can be used for broadband spectroscopy, for example from 2 00 to 800 nm, when the compensator retardation delta is known as a fun ction of wavelength and sample properties are determined by least-squa res methods. The resulting instrument offers the standard advantages o f an RCE and is no less sensitive than a rotating-analyzer or -polariz er ellipsometer under worst-case conditions, where the sin (2 omega t) component vanishes at delta=180 degrees C. Sensitivity and operation are illustrated by application to the measurement of crystalline Si. ( C) 1998 Elsevier Science S.A.