Technology Roadmap Comparisons for TAPE, HDD, and NAND Flash: Implications for Data Storage Applications

This paper describes the roadmap goals for tape based magnetic recording (TAPE) and uses these goals as counterpoints for the roadmap strategies for hard disk drive (HDD) and NAND flash. Technology comparisons described in this paper will show that presently volumetric efficiencies for TAPE, HDD, and NAND are similar, that lithographic requirements for TAPE are less challenging than those for NAND and HDD, and that mechanical challenges (moving media and transducer to media separation) for TAPE and HDD are potential limiters for roadmap progress and are non-existent for NAND. One result of the technology comparison discussion will be that the potential for sustained annual areal density increase rates, i.e. extendibility, for TAPE, is significantly greater than that for NAND and HDD due to the present TAPE bit cell area being a factor of 200-300 larger than the NAND and HDD bit cell area. More critically, the roadmap landscape for TAPE is limited by neither thin film processing (i.e., nanoscale dimensions) nor bit cell thermal stability. In contrast, NAND volumetric density faces limitations in extending critical feature processing, now at 25 nm, and HDD volumetric density faces challenges in transitioning either to patterned media with critical feature processing well below 15 nm or to heat assisted magnetic recording (HAMR) with the introduction of laser components to the data write process.