Etching of Silicon - Electrochemistry of Silicon and Its Oxide - page 345

structural perfection of single crystals. The morphological features developed by defect
etching have a characteristic shape and may occur at random or in arrays revealing
crystalline imperfections such as dislocation, slip, lineage, and stacking faults. Defect
etching has been widely used to evaluate dislocations and also to delineate process-
induced defects in silicon wafers and epitaxial deposits. 375,387 In general, the etching
features and operating conditions in different defect etching systems are well charac-
terized but the etching processes that lead to the development of the defect features are
not well understood. The techniques and procedures for defect etching of silicon crystal
are well established and can be found in a series of ASTM Standards. 439-442
Many different etchants have been developed for various purposes as shown
in Table 7.7. By using proper etchants and procedures, different types of crystal
faults, 387,433,1023 defects can be evaluated: flow pattern defects, 246 stacking