ABSTRACT
Single-crystal silicon grown by both the Czochralski (CZ) process and the oat-zone (FZ) process inherently contains many crystallographic imperfections popularly known as microdefects or grown-in defects. Prior to the 1960s, crystals contained dislocations induced by the thermomechanical stresses near the vicinity of the melt-crystal interface. A major breakthrough by Dash [1] allowed crystal growth without the thermomechanically induced dislocations, and this brought a revolution in growing single crystals of silicon with minimum defects. However, even though the crystals are free of thermomechanically induced dislocations, various other microdefects can form through an agglomeration of point defects that exist as solutes in the silicon crystal matrix. There are two basic types of point defects in silicon: vacancies, which are formed when a silicon atom is missing from the regular lattice site, and self-interstitials (or simply, interstitials), which are interstitial silicon atoms not bonded with the other silicon atoms forming the lattice. Microdefect dynamics, or simply defect dynamics [2], is a collective term that describes the interplay between the point defects transport, the Frenkel reaction, the nucleation of the point defects, and the growth of the microdefects. The two-dimensional gures in Figures 9.1 and 9.2 show various defects that are generally present in the silicon crystal lattice.
