Thin Solid Films 443 (2003) 115–119 0040-6090/03/$ - see front matter  2003 Elsevier B.V. All rights reserved. doi:10.1016/S0040-6090(03)01031-9 Deposition of permalloy films by filtered cathodic vacuum arc J.S. Chen , S.P. Lau*, Y.B. Zhang, Z. Sun, B.K. Tay, C.Q. Sun 1 Ion Beam Processing Laboratory, School of Electrical and Electronic Engineering, Nanyang Avenue, Nanyang Technological University, Singapore 639798, Singapore Received 11 February 2003; received in revised form 14 May 2003; accepted 16 July 2003 Abstract The filtered cathodic vacuum arc technique was employed to deposit magnetic films such as FeNi on silicon substrate. Using the normal cathode design, tetrahedral amorphous carbon and metals films can be deposited. If a magnetic target is used, the arc spot always preferably moves to the edge of the target and then extinguishes. Therefore, the arc is not stable and no film can be deposited. A cathode was designed to obtain stable and continuous arc and uniform erosion pattern. The atomic force microscopy, grazing X-ray diffraction and vibrating sample magnetometry were used to characterize the morphological, structural and magnetic properties of the FeNi film. When the film deposited at substrate bias of y100 V, it exhibits a square magnetization–hysteresis loop, the lowest coercivity and the highest saturated magnetization among all the investigated samples, which may be related to its good surface roughness and crystallinity.  2003 Elsevier B.V. All rights reserved. Keywords: Permalloy; Filtered cathodic vacuum arc; Magnetic properties 1. Introduction For many years there has been considerable interest in producing films of magnetic materials because of their many exclusive applications such as magnetic recording, microactuation and sensors and so on. Many techniques have been employed to synthesize the mag- netic films with varying amounts of success, which include evaporation, sputtering, pulsed laser deposition, and molecular beam epitaxy w1–3x. Among them, the evaporation and sputtering are predominant in industrial application because of their economy and simplicity. But the need for new, high performance materials in magnetic recording entails the development of a new deposition technology for magnetic films. It is well known that cathodic vacuum arc technology has proven to be a very promising method for ultrathin film depo- sition. It offers several advantages over evaporation and *Corresponding author. Present address: Data Storage Institute, 5 Engineering Drive 1, NUS, Singapore 117608, Singapore. Tel.: q65- 67906439; fax: q65-67933318. E-mail addresses: esplau@ntu.edu.sg (S.P. Lau), chen_jingsheng@dsi.a-star.edu.sg (S.P. Lau). Present address: Data Storage Institute, 5 Engineering Drive 1, 1 NUS, Singapore 117608. sputtering, and the principal advantages are the high percentage of ions in the emitted flux (approx. 100%), high kinetic energy of these ions (20–200 eV) w4,5x. In the present time, it has been in wide-scale industrial use for producing wear protective coatings of TiN and related materials on cutting and forming tools, as well as decorative coatings on plumbing fixture and jewelry. Adding a magnetized torus macroparticle filter the high- ly tetrahedrcally bonded amorphous carbon films can be synthesized with high deposition rate (5 nmys) at room temperature w6x. The filtered cathodic vacuum arc (FCVA) technique has also been used for depositing optical thin films of metal oxides (TiO and Al O ) and 2 2 3 semiconducting thin films (amorphous Si and SnO ) 2 w7–9x. To our knowledge, however, no paper has been reported on the deposition of magnetic films by FCVA technique yet. In this paper, the FCVA technique was used to deposit FeNi films on Si substrate. A modified cathode design for depositing magnetic films was presented. 2. Movement of cathode arc spot and cathode design The typical FCVA system has been described else- where w10x. Generally, a conductive target mounted on