Erasing and jitter variation mechanisms of Ag-In-Sb-Te compact disk-rewritable at double and quadruple compact disk velocities

The erasing mechanisms of Ag-In-Sb-Te compact disk rewritable (CD-RNV) at C D 2x and CD 4x are studied by employing transmission electron microscopy (T EM). The mechanisms of laser-induced crystallization vary with linear veloc ity as well as erase power. Under CD 2x recording, erasing proceeds with nu cleation and grain growth at low erase laser power. However, it is the dire ct grain growth that controls the mechanism of erasing at high erase laser power. Under CID 4x recording, erasing is dominated by direct grain growth originating from the interface between amorphous marks and their neighborin g crystalline region, and the erase power determines the location where gra in growth begins. In addition, a sharp increase in jitter after overwriting at CD 4x was observed as a result of the existence of two different amorph ous marks. One of them has a normal shape and the other is extended with a tail in the trailing part. For over-writing more than 50 times, only one ty pe of amorphous mark with a tiny sharp tail was observed, This single type of amorphous mark gives rise to a decrease in jitter.