Abstract
Plasma etching treatment of SiN underlayer was performed to enhance the magnetic sensitivity of TbFeCoCr magnetic-optic disc which facilitates the magnetic-field-modulation direct overwriting behavior. The effect of plasma etching on the interfacial structure was investigated by high-resolution electron microscopy and stress measurements. The ordered structure at the interface between SiN underlayer and MO Layer was observed for samples with highly etched underlayer. Compressive residual stress was induced by the plasma etching of SiN underlayer. The results suggest that the magnetic sensitivity is improved by less pinning sites and the lower domain wall energy density at the interface.