Paper TF+MI-WeM5
Comparing Deep Reactive Ion Etching vs. Ion Milling for Block Copolymer Templating for Bit Patterned Media
Wednesday, October 30, 2013, 9:20 am, Room 102 C
| Session: |
Magnetic Thin Films and Nanostructures |
| Presenter: |
A. Owen, University of Alabama |
| Authors: |
A. Owen, University of Alabama
S. Gupta, University of Alabama
A. Highsmith, University of Alabama
A. Montgomery, University of Alabama
H. Su, University of Alabama
R. Douglas, University of Alabama
|
| Correspondent: |
Click to Email |
Block copolymer templating has been used to pattern perpendicular magnetic anisotropy Co/Pd multilayers.1 A multilayer stack of Ta 5Pd 5/[Co 0.3/Pd 1]20 /Pd 5 nm nanolayers was sputter deposited onto a bare silicon wafer. The block copolymer used was polystyrene polyferrocenyldimethylsilane2 (PS-b-PFS). This was spin coated onto the wafer and annealed to cause phase separation.2 The wafer was ashed in an oxygen plasma to remove the polystyrene matrix and reveal the PFS nanospheres. The Co/Pd multilayer films were subsequently etched using an ion mill and a deep reactive ion etching tool.3 In order to optimize the size tuning of the PFS nanospheres and the coercivity of the magnetic films,response surface methodology was performed to optimize the power, etching times and ashing time of the block copolymer mask and magnetic film. This statistical Design of Experiments was used for both ion milling and deep reactive ion etching. We will discuss some of the shapes of the resulting nanopillars from the different etching techniques. Magentometry was taken to characterize the films before and after patterning, showing a significant improvement in the coercivity, increasing from 1.5 kOe to 3.6 kOe. Acknowledgements
NSF ECCS 0901858 “GOALI: Nanopatterned Graded Media” is acknowledged for partial support. The UA Microfabrication Facility and the Central Analytical Facility are acknowledged for support and use of facilities.
References
1. 1. O. Hellwig, J. K. Bosworth, E. Dobisz, D. Kercher, T. Hauet et al. ,Appl. Phys. Lett. 96, 052511 (2010)
2. 2. Joy Y. Cheng, Feng Zhang, Henry I. Smith, G. Julius Vancso, and Caroline A. Ross, Adv. Mater., 18, 597,(2006)
3. 3. Xiao Li, Z.R. Tadisina, S. Gupta, G. Ju, J. Vac. Sci. Technol. A 27, 1062, (2009)