Abstract
The erasing mechanisms of Ag-In-Sb-Te compact disk rewritable (CD-RW) at CD 2x and CD 4x are studied by employing transmission electron microscopy (TEM). The mechanisms of laser-induced crystallization vary with linear velocity as well as erase power. Under CD 2x recording, erasing proceeds with nucleation and grain growth at low erase laser power. However, it is the direct grain growth that controls the mechanism of erasing at high erase laser power. Under CD 4x recording, erasing is dominated by direct grain growth originating from the interface between amorphous marks and their neighboring crystalline region, and the erase power determines the location where grain 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 amorphous marks. One of them has a normal shape and the other is extended with a tail in the trailing part. For overwriting more than 50 times, only one type of amorphous mark with a tiny sharp tail was observed. This single type of amorphous mark gives rise to a decrease in jitter.