Area selective formation of magnetic nanodot arrays on Si wafer by electroless deposition

• Published in: Journal of magnetism and magnetic materials Vol. 287; pp. 245 - 249
• Main Authors: Kawaji, J., Kitaizumi, F., Oikawa, H., Niwa, D., Homma, T., Osaka, T.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.02.2005; Elsevier Science
• Subjects: Area selective formation; Condensed matter: electronic structure, electrical, magnetic, and optical properties; CoNiP alloys; Electroless deposition; Exact sciences and technology; Magnetic properties and materials; Patterned media; Pd activation process; Physics; Area selective formation; 81.16.−c; CoNiP alloys; Electroless deposition; 75.50.Ss; 81.16.Be; Patterned media; 75.75.+a; Pd activation process; Inorganic compounds; Magnetization; Selective area; Electron beam lithography; 81.16.-c Patterned media; Deposition process; Pore size; Reactive ion etching; Chemical activation; Anisotropy; Silicon oxides
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2004.10.040

Electroless deposition process for fabricating magnetic dot arrays was studied. A patterned Si substrate with a SiO2 resist was produced by processes combined with electron-beam lithography and reactive ion etching. By immersing the patterned Si substrate into a CoNiP electroless deposition bath, CoNiP was deposited only into the patterned pores, demonstrating a satisfactory area selectivity of the deposition. Excellent uniformity on the CoNiP deposition into the patterned pores with diameter less than 100nm and high aspect ratio (>5) was achieved by applying chemical activation processes using a Pd solution prior to the deposition. The CoNiP dot arrays exhibited higher perpendicular squareness ratio than that of CoNiP continuous film and showed a clear magnetization state at DC-magnetized state, which originated from the shape anisotropy caused by high aspect ratio of the dot patterns.