ATOMIC STEP AND DEFECT STRUCTURE ON SURFACES OF SI(100) SI(111) OBSERVED BY LOW-ENERGY ELECTRON-MICROSCOPY

The Si{100} and Si{111} surfaces are studied by low-energy electron microscopy. Atomic step and terrace structure formed by misorientation of Si wafers is investigated as well as various migration patterns of atomic steps formed during sublimation. Slip traces ending typically at screw dislocations form along ‘110’ directions in the surface and create additional atomic steps. Analysis of migration patterns near slip traces implies that both partial and perfect dislocations (or their equivalent, namely two partials) form on Si {100}. Perfect dislocations are seen on Si{111}. Regions with the (7×7) structure on Si{111}, which contain stacking faults, are imaged. Surface domain structure and domain boundaries are seen on Si{111}. On Si{100} the partial dislocations create two new types of surface domain displaced relative to the two pre-existing (2 × 1) and (1 × 2) domains. The potential for in situ studies of process-induced defects on Si wafers is demonstrated. © 1990 Taylor & Francis Group, LLC.