A Novel Multilayered Ni-Zn-Ferrite/TaN Film for RF/Mobile Applications

作者：Kaneko Kishou^*; Inoue Naoya; Furutake Naoya; Hayashi Yoshihiro

来源：Japanese Journal of Applied Physics, 2010, 49(4): 04DB15.

DOI：10.1143/JJAP.49.04DB15

A novel multilayered Ni-Zn-ferrite/TaN (MFT) film is developed for RF/mobile complementary metal oxide semiconductor (CMOS) applications. The Ni-Zn ferrite (Ni0.5Zn0.5Fe2O4) film is deposited by low-temperature RF magnetron sputtering technique applicable for conventional low-k/Cu interconnects in advanced CMOS LSI. In the MFT film, a stacking unit of thin Ni-Zn-ferrite and thin TaN is laminated to enhance the ferrite (311)(spinel) orientation close to the magnetization easy axis of the ferrite. The saturated magnetization (M-s) increased 50% referred to the single-layer Ni-Zn-ferrite/TaN, and the coercivity (H-c) decreased one-fifth desirable for the high speed switching. By physical-based modeling, it is proved that the fraction of the (311)-orientation region in the total ferrite thickness is very important to improve the magnetic properties. In addition to the high resistivity (rho = 10 M Omega cm) to suppress eddy current loss, the MFT film is effective to confine and enhance the magnetic field in the on-chip inductor in GHz range, suitable for RF/mobile applications.

• 出版日期2010