Crystal orientation determination in wafer having zinc blende structure - performing reflectometry of four angles between edges of etched groove and longer sides of mask opening

摘要

An etching mask (2) is formed on the wafer (1) with a stripe-shaped opening (3) having a pointed projection (6,7) from each of the longer sides in a direction along a predetermined marking. After anisotropic etching, the angles (alpha 1, alpha 2, beta 1, beta 2) between the edges (15,16) of the etched groove (8) and the longer sides of the opening are found by measurement of the under-etched mask regions (11-14). The crystal orientation is computed from the measured angles. USE/ADVANTAGE - For silicon or Gallium Arsenide wafers. Allows determination of orientation in space as well as w.r.t. predetermined flat on wafer surface.