Soft Magnetic Materials 13

J. Phys. IV France 08 (1998) Pr2-363-Pr2-366
DOI: 10.1051/jp4:1998285

Soft magnetic properties of as-deposited Fe-Hf-C-N films by N₂ reactive RF magnetron sputtering

J.Y. Song¹, J. Kim², H.J. Kim³ and J.J. Lee<sup>1

1</sup>  Department of Metallurgical Engineering, Seoul National University, 151-742 Seoul, Korea
²  Department of Metallurgy and Material Science, Hanyang University, Ansan, 425-791 Kyungki, Korea
³  Thin Film Technology Research Center, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang Ri, 130-650 Seoul, Korea

Abstract
The soft magnetic properties of as-deposited FeHfCN films prepared by N₂ reactive RF magnetron sputtering have been investigated. The excellent soft magnetic properties, particularly high frequency permeability, in the as-deposited state are achieved by controlling the film composition and sputtering conditions, such as N₂ partial pressure and input power without post annealing. As-deposited films composed of 8 ~ 10 at% Hf, 17 ~ 19 at% (C +N), balanced Fe, exhibit the soft magnetic properties of 4πM, H_c = 0.4 Oe, especially high permeabilities of over 3000 which remain nearly constant up to 100 MHz. The analysis of TEM and XRD shows that the as-deposited films consist of finely dispersed a -Fe(grain size ~4 nm) and Hf(C,N)(grain size ~2 nm) precipitates, which are crystallized during sputtering deposition. The present thin films are different from Fe-TM(Nb, Zr, Ta, Hf, etc)-(C,N) films, which are amorphous in the as-deposited state and then nanocrystallized only through an optimum annealing procedure. Furthermore, the soft magnetic properties of the as-deposited films are not degraded after annealing of 823 K, 30 min.

© EDP Sciences 1998