Thin-Film Processing Realities for Tbit/in2 Recording

Magnetic recording has maintained a cost/bit advantage over solid-state storage by using a single transducer to self-assemble bits with sub-lithographic dimensions on an unpatterned substrate. This paper explores the ability of magnetic recording to maintain this advantage at 1 Tbit/in(2) by examining the process challenges associated with the fabrication of head structures at this areal density. Specifically, this paper describes the minimum feature, F, and alignment requirements for the thin-film head structures supporting I Tbit/in(2) densities and compares these requirements with the projected roadmaps of the semiconductor industry. These comparisons indicate that minimum feature head processing requirements will match semiconductor capabilities in the time frame for I Tbit/in2 recording product. Further, alignment requirements for the head structure will exceed projected semiconductor capabilities in this same time frame. The process implications of the technologies of discrete tracks and patterned bits are analyzed, which move the minimum feature requirements from the head structure to the disk media. These approaches require patterning sub-lithographic bit cell dimensions which by definition exceed semiconductor lithographic capabilities.