Definition of slip

in semiconductor wafers, a process of plastic deformation in which one part of a crystal undergoes a shear displacement relative to another in a manner that preserves the crystallinity of each part of the material. DISCUSSION-After preferential etching, slip lines are evidenced by a pattern of one more more parallel straight lines of dislocation etch pits that do not necessarily touch each other. On |111| surfaces, the group of lines are inclined at 60 degrees to each other; on |100| surfaces, they are inclined at 90 degrees to each other. [SEMI M10-89 and ASTM F1241] Also see pit.