Major Defects

A real crystal, as represented by a silicon wafer, differs from a mathematically ideal crystal in several aspects. A real crystal is finite in structure and not infinite like an ideal crystal; thus surface atoms are incompletely bonded. Also in real crystals atom are displaced from their ideal locations by thermal agitation.

Most importantly the real crystals have the following classifications of defects:

· Point defect

· Line defect

· Area or planar defect

· Volume defect