INTERFERENCE MEASUREMENT OF THIN SURFACE LAYERS 1219 



COPPER-PLATED BODY 



ORIGINAL 

 -SURFACE OF 

 GERMANIUM 



BEVELED 

 SURFACE 



Fig. 9 — Evaluation of the interference fringe pattern on a Cu-plated p-n junction. 



"" • '*i«^^Nfciiir 



Fig. 10 — Evaluation of the interference fringe pattern of a shallow step in a 

 surface. 



