Date Approved


Embargo Period


Document Type


Degree Name

M.S. in Engineering


Electrical & Computer Engineering


Henry M. Rowan College of Engineering


Krchnavek, Robert


Computer storage devices--Materials; Magnetic memory (Computers); Nanoimprint lithography


Electrical and Computer Engineering


Advances in technology are having profound effects throughout society. This is no truer than in the way information is being stored. The primary form of information storage for at least the past millennium has been paper. Today, an ever increasing amount of information is being stored electronically. An increased demand for high-performance, low-cost information storage has been a major catalyst in increasing the popularity of hard drives. In 2002, two exabytes of original information was stored on hard drives. This is ten times the amount of all printed material in the world if it were converted to electronic files. To keep up with this demand, the capacity of hard drives has increased by at least 60% annually since 1991. The capacity has mainly increased by scaling down the relevant dimensions much in the same way that has been done with microprocessors. Scaling cannot indefinitely be used to increase the capacity of hard drives that employ longitudinal magnetic recording. Before long, the superparamagnetic effect will limit the achievable information capacity of hard drives using conventional recording. Therefore, new technologies will be needed. Perpendicular recording, one of several new technologies, will make its entrance into the market later this year in a hard drive designed by Toshiba for Apple's iPod music player. It is said that the hard drive will have an areal bit density of 133 Gbits/in2. This is an increase of 75% over what is currently available today. However, the hard drive will still employ a continuous magnetic medium. Even greater densities can be achieved if the magnetic medium is physically patterned into isolated bits. This technology, known as patterned magnetic media, has the potential of achieving areal bit densities greater than 1 Tbit/in2. The challenge is finding a way to fabricate it. A high-throughput, low-cost pattern generation technology is needed. Research completed with nanoimprint lithography demonstrates that it can be used to fabricate patterned magnetic media. Several patterns of magnetic media were fabricated with densely packed sub-20-nm features that would produce an areal bit density of at least 258 Gbits/in2.