Potential of a rotary stage electron beam mastering system for fabricating patterned magnetic media

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.