To fabricate master templates of high-density patterned magnetic media, the authors developed a high-resolution and high-throughput rotary stage electron beam mastering system. They accomplished the fabrication of discrete track media groove patterns with 45nm track pitch, and also a dense bit array with both track and bit pitch of 35nm for bit patterned media under the conditions of a bit rate of 1.22MHz∕bit at 50kV acceleration voltage. The high resolution and high throughput are derived from using a continuous stage movement flyback lithography (CSFL) function. CSFL is enabled by differentiated capabilities, such as an electron optical column that achieves a large beam current at a small beam diameter, and a friction-driven slider stage that provides a highly accurate positioning capability and a dynamic focus correction feature and r-theta stage driving. The CSFL capability, working in conjunction with a blankingless beam shift lithography (BLSL), is very effective for fabricating various kinds of servo pattern elements, such as grooves and dots, grooves and right-angled grooves, grooves and half-pitch-shift dot arrays, and various pit length patterns, to construct effective servo patterns.

An electron beam lithography (EBL) system, CABL-UH, with a 130 kV high acceleration voltage has been developed that succeeded in minimizing beam size by minimizing Coulomb blur. This system has a short single-stage electron beam (EB) gun with an alignment function of two extractor centers to minimize Coulomb blur. This gun has also succeeded in thoroughly avoiding microdischarges. By adopting this EB gun and many other techniques, high resolution and long-term high stability have been achieved and an extremely fine pattern (4 nm line) has been delineated.

A slider and spindle (r -) stage electron beam (e-beam) mastering system with continuous-stage-movement blankingless beam shift lithography (BLSL) and flyback e-beam lithography (CSFL) brings together the features of high resolution, high accuracy, and high throughput to meet the various requirements for fabricating master templates for discrete track media and bit patterned media (BPM) for the next generation of hard disk drives. With the CSFL capability, we achieve multiple-overlay bit writing with one, two, four, and eight overlays for a BPM bit array to markedly improve track-to-track phase alignment accuracy from 5.6 nm sigma in a single write to 1.04 nm sigma in an eight overlay write. CSFL, in conjunction with the high-frequency response of the e-beam deflector, achieves 25 MHz high-throughput BPM bit array write with track pitches and bit pitches of 120 nm in the entire write range from 20 to 140 mm in diameter. This write takes only 11.6 h under the conditions of a line velocity of 3,000 mm/s, a beam current of 150 nA, a maximum rotation speed of 2,865 rpm, and a constant line velocity (CLV) write mode.