Performance study and analysis of dual-element head on thin-film disk for gigabit-density recording

5 Gb/in/sup 2/ recording demonstration with conventional AMR dual element heads and thin film disks

“…The value of jd here corresponds to a 40% disk noise reduction over that in the previous 3 Gb/in2 work, from both continued optimization of the the quaternary CO alloys as well as better writing at a smaller magnetic spacing. This improvement, coupled with increases in the non-disk noise jitter from an increased bandwidth for higher data rate operation, renders the disk noise jitter smaller than the non-disk noise jitter, in contrast to the previous 1 & 3 Gb/in2 results [4,10]. In comparison to head A, head B exhibited a smaller non-disk noise jitter due to a larger readback signal, but a larger disk noise jitter due to the reading of track edge noise from a smaller readwrite margin [15], resulting in a roughly similar total jitter.…”

“…2) for both heads shows small write threshold currents at the 50% signal level of 30-32 mA (p-p), and thorough saturation of the media at write currents beyond 55 mA. No discernible signal reduction was observed at high write currents [4,10], indicating that problems of partial erasure or write field gradient reduction from excess write field were not present with the narrow pole-tips. In the overwrite measurement, a 1000 fclmm transition pattern is overwritten by a 1 fc/mm transition pattern, and the signal reduction at the fundamental frequency of the old pattern is recorded.…”

“…In comparison to head A, head B exhibited a smaller non-disk noise jitter due to a larger readback signal, but a larger disk noise jitter due to the reading of track edge noise from a smaller readwrite margin [15], resulting in a roughly similar total jitter. Finally, as discussed previously [4,5], the ontrack signal-tonoise performance can be quantified by assuming peak detection and computing the ratio (F) of the timing window to the total peak jitter. The present systems yield F values of -6.2, suggesting viable performance with a PRML channel.…”

“…Next, the offtrack and squeeze performance were studied by peak jitter techniques [4]. To study the offtrack performance, total jitter was recorded as a function of head offtrack positions.…”

Electron cyclotron resonance plasma etching of materials for magneto-resistive random access memory applications

“…[1][2][3] Other materials such as TaN and CrSi can be also used as oxidation or contact barriers, respectively, in magneto-resistive random access memory (MRAM) stacks. [1][2][3] Other materials such as TaN and CrSi can be also used as oxidation or contact barriers, respectively, in magneto-resistive random access memory (MRAM) stacks.…”