No abstract

Nitrogen ion implantation was performed on CoCrPt–SiO2 perpendicular media with a resist mask to fabricate patterned media. Signal amplitude and autocorrelation signal-to-noise ratio of the preamble pattern were measured to evaluate the quality of the pattern fabricated by the ion implantation. The signal-to-noise ratio and the jitter were closely related to the saturation magnetization of the ion-implanted area. The remained magnetization of the ion-implanted area probably affects edge roughness of the magnetic pattern. Larger reduction of the saturation magnetization at the ion-implanted area is important for obtaining higher signal quality. Off-track profiles and 747 curves were measured for 76-nm-pitch discrete track fabricated by ion implantation. The results show that discrete track recording had advantages over recording on continuous magnetic film, which indicates that the fabricated patterns were successfully isolated. The nitrogen ion implantation was effective in fabricating isolated magnetic tracks or isolated magnetic dots for the patterned media.

Effects of low-energy (1-1.5 kV) nitrogen-ion bombardment on sharply pointed tips: Sputtering, implantation, and metal-nitride formation

No abstract

Patterned media were fabricated by nitrogen ion implantation and changes of the pattern quality with ion energy were evaluated by analyzing the readback signals. The ion energies were 8, 12, 14 and 16 keV, and the dosage was 2.5×10 16 ions/cm 2 . Auto correlation signal to noise ratio of DC-magnetized preamble pattern was maximized at 12 keV, though the saturation magnetization of the ion-implanted area was decreased as the ion energy increased throughout the range from 8 keV to 16 keV. 2D-maps of the signal amplitude showed larger fluctuation of the pattern shape for the ion energy of 16 keV than for the ion energy of 8 keV. The standard deviations of the pattern width were 4.3 nm and 8.4 nm for 8 keV and 16 keV, respectively, which were almost the same values as the standard deviations of calculated ion lateral distribution. The results indicate that some ions distributed under the mask by the ion lateral straggling and thus affected the pattern quality. For high quality patterning, ion lateral straggling needs to be suppressed by lowering ion energy.