TRANSMITTED COLOR AND INTERFERENCE-FRINGES FOR TEM SAMPLE PREPARATIONOF SILICON

Transmission electron microscopy (TEM) silicon samples backlit with an optical light source display a series of colors in regions of less th an 10 mu m thickness and a series of interference fringes in regions o f less than 2 mu m thickness. These colors and fringes result from the transmission, reflection, absorption and interference of light within the sample, and depend upon the light source and the sample thickness . One promising application of these observations is their use as a te chnique to monitor sample thickness during the preparation of TEM samp les. We present direct measurements of silicon color versus thickness, the factors that influence this relationship, and the origin and sign ificance of the interference fringes. Crown copyright (C) 1998 Publish ed by Elsevier Science Ltd. All rights reserved.