
362 Crystal Growth and Evaluation of Silicon for VLSI and ULSI
10.6 Denuding of Silicon Wafers
Microdefects existing in the active region, close to the CZ silicon wafer surface, have many
detrimental effects on the performance of semiconductor devices. Hence, it is desirable to
eliminate them by providing a nearly defect-free zone, which is commonly referred to as
a “denuded zone,” in the active region of silicon wafers where most of the devices are fab-
ricated. These are the subsurface regions where no signicant microdefects are detected
with an optical microscope. These denuded zones can form near the silicon surfaces if
the wafers are subjec ...