Flexible Magnetics: Magnetic Lithography and Fabrication of Magnetic Masks on Thin Plastic Substrates
- PDF / 539,671 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 93 Downloads / 207 Views
H7.1.1
Flexible Magnetics: Magnetic Lithography and Fabrication of Magnetic Masks on Thin Plastic Substrates Z. Z. Bandi ´c,1 H. Xu,1 J.E.E. Baglin,2 T. R. Albrecht,2 1 Hitachi San Jose Research Center 650 Harry Rd., San Jose, CA 95120 2 IBM Almaden Research Center, 650 Harry Rd., San Jose, CA 95120 ABSTRACT Flexible magnetic lithography is a process qualitatively analogous to contact optical lithography which transfers information from a patterned magnetic mask (analog of optical photomask) to magnetic media (analog of photoresist), and is interesting for applications in instantaneous parallel magnetic recording. The magnetic mask consists of patterned soft magnetic material (FeNiCo, FeCo) on a flexible plastic substrate, typically Polyethylene Teraphtalate (PET). When uniformly magnetized media is brought into intimate contact with the magnetic mask, an externally applied magnetic field selectively changes the magnetic orientation in the areas not covered with the soft magnetic material. Flexible substrate of the magnetic mask offers superior compliance to magnetic media which is likely to have imperfect flatness and surface particulate contamination. Although magnetic in physical nature, flexible magnetics draws interesting parallels to flexible electronics, especially in challenges of fabrication of sub-micron patterns on thin flexible plastic substrates. We fabricated samples of sub-micron patterned FeCo and FeNiCo magnetic masks on PET substrates by using combined lamination/release process of PET films. Rigid substrates, typically silicon or quartz were initially laminated with PET films and processed using standard fabrication procedures. After completing magnetic mask device fabrication, PET films were released from the rigid substrates. We successfully transferred patterns from magnetic masks to hard disk CrPtCo-based magnetic media. The details of the method, including physics of the magnetic lithography pattern transfer, fabrication of the magnetic mask on flexible PET substrates, lamination and release of PET films, and magnetic force microscopy (MFM) images of the magnetic transition patterns are reported. INTRODUCTION Multiple writing of the same information is very common in the magnetic recording, typical examples being formatting of the magnetic media, recording digital content (such as music and video) for high-volume distribution, or recording head positioning (servo) information. All these applications would dramatically benefit from parallel recording, which would significantly reduce recording time when compared to conventional serial (or track by track) approaches. One approach to parallel magnetic recording is magnetic lithography (ML) [1, 2]. The ML method derives its name from analogy to contact optical lithography and is qualitatively explained in Fig. 1. The magnetic mask is analogous to an optical photomask, the magnetic media is analogous to optical resist, and external magnetic field is analogous to a light source. Since magnetic media frequently exhibits non-flatness and particle con
Data Loading...
