A UNIVERSAL WAFER FLAT FINDER
Original Publication Date: 1991-Apr-01
Included in the Prior Art Database: 2001-Dec-07
Silicon crystals as used throughout the semi- conductor industry have portions of their outer surfaces ground to SEMI standard dimensions and locations thereby creating so-called "flats" (both primary and secondary) on wafers sliced from the crystals. These "flats" should directly correspond to the conductivity type of the crystal (Positive or Negative) and are used also for purposes of alignment and orientation during subsequent wafer processing steps. These "flat" dimension and tolerance specifi- cations also vary as a function of the crystal and wafer diameters.