Enhanced adhesion of a film of non-reactive metal deposited on a ceramic or glass substrate can be produced by irradiating the interface with an ion beam. The resulting bond can be improved by subsequent heat treatment. The interface remains abrupt. The mechanism of this bonding is discussed, and the effects of interface contaminants are examined for the Cu-Al 2 O 3 and Au-Al 2 O 3 systems. Finally it is noted that strong adhesion is produced when Al 2 O 3 is subjected to preferential sputtering at the time of Cu deposition; the resulting interface chemistry is discussed.

Cooper and platinum films were deposited by evaporation and sputtering techniques onto prepared substrates of alumina, sapphire (cut along an a or c axis) and yttria stabilized zirconia. The films are then bombarded with ions of H, He, Ne and Kr at energies within and outside the ion beam mixing regime. Ion beam induced modification in adhesion and its thermal stability were measured by three techniques — a scratch test, a pull test and a peel test. Adhesive energies of these solid-solid systems were determined by contact angle measurements using scanning electron microscopy. The resistance of the films to chemical attack is modified by ion bombardment and will be shown to correlate with adhesion alterations.

The mechanisms and effectiveness of corrosion protection provided by thin ion-beam carbon coatings on Cu, Fe, Mn and Co are discussed. A thin (# 10 Å) layer of protective carbon is produced on metal surfaces by ion-beam dissociation of adventitious or intentional hydrocarbon adsorbates. Below 200°C, oxidation is strongly inhibited, as is corrosion in a humid, sulphurous ambient. Above 200°C, the carbon layer may itself be destroyed by oxidation, due to catalytic action of the metal surface. Thicker PVD carbon (up to 60 Å) was not an effective corrosion barrier, even after ion irradiation. A technique for producing high integrity ion-beam carbon layers of high stability and durability is discussed.

A series of experiments have been performed to examine the ability of ion beam assisted thermal deposition to produce good adhesion of Au metallization on GaAs <100> substrates. A study of the influence of Ar ion-assisted thermal deposition of the Au films as well asin situ pre-sputtering of the GaAs surface with low-energy Ar ions prior to thermal deposition, shows that strong adhesion can be achieved without resorting to chemical cleaning. The substrate temperature and the relative flux of Ar ions to incident Au atoms were varied in order to correlate these parameters with film adhesion. The interfaces of films processed under these various conditions were examined by XTEM, RBS and XPS. Orientation texture was studied by x-ray diffraction (XRD).

In this letter, a direct measurement of a refractive index change in potassium gadolinium tungstate (KGW) created by a low-dose ion implantation of 1 MeV hydrogen ions is reported. The characterization was performed using both microreflectivity and Raman spectroscopy measurements. The microreflectivity results show both negative and positive changes in refractive index in the damage region when measuring refractive index along different polarization axes. Micro-Raman spectroscopy analysis shows preservation of the Raman characteristics of KGW in the nondamaged crystal regions. These results show that ion implantation in KGW has a great potential for fabricating waveguide structures in Raman-based photonic devices. (c) 2006 American Institute of Physics.

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 o.ers 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.

Large-field ion-optics has been developed for reduction printing. Sub-100nm ion projection direct-structuring (IPDS) of patterned magnetic media discs has been demonstrated, extending over 17mm diameter exposure fields, in a single exposure. First results of IPDS patterning of nanocomposite resist material are presented. Information about a novel 200x reduction projection focused ion multi-beam (PROFIB) tool development is provided. Further IPDS nanotechnology applications are discussed.

The switching behavior of magnetic patterns prepared by ion irradiation was investigated. Co/Pt multilayers with perpendicular anisotropy and large out-of-plane coercivities 5–6 kOe were grown on electron transparent SiN windows. Regularly spaced 1 micron sized regions, were magnetically pattered via ion beam irradiation through a stencil mask. Lorentz TEM was used to observe in-situ magnetization reversal processes of irradiated regions under well-defined applied magnetic fields. When the in-plane field was increased, domain wall motion was observed, resulting in the alignment of the patterns with the direction of the applied field. The switching mechanism of the in-plane patterns was by domain wall motion.

Several techniques reported to be effective for the preparation of thin films of cubic phase boron nitride (c-BN) are reviewed. In order to maintain integrity and adhesion for such films at a useful thickness, it is critical to minimize their intrinsic stress. A method is detailed for stress reduction by MeV ion irradiation following the deposition of c-BN films. Based on these successful processes, a new method is proposed. in which the production of stress-reducing atom displacements is achieved during ion-assisted c-BN deposition, by concurrent bombardment of the growing film with energetic ions, typically at keV energies. (C) 1999 Elsevier Science S.A. All rights reserved.

Multilayered metal films including such couples as Ta-Permalloy (Ni80Fe20) play a key role in magnetic recording sensors, where it is important to preserve the integrity of the thin permalloy layer under thermal conditions during processing and subsequent service. Earlier work1 has indicated a fast grain boundary diffusion of Ta in Ni films at temperatures as low as 250°C. In this paper, we report measurements of the kinetics of this diffusion, in the temperature range 300–400°C. For this work, layered Ni/Ta systems were prepared under controlled conditions, annealed in a helium-flow furnace, and characterized by RBS, AES, XRD and SEM. The possible consequences of diffusion on magnetic performance are also discussed.

Thermal interdiffusion mechanisms and kinetics have been studied for Ta-Permalloy (Ni80Fe20), Ta-Ni and Ta-Fe thin film couples, in the temperature range 300°C - 600°C. Interaction modes identified for the Ta-NiFe system include: fast diffusion of Ta into grain boundaries of NiFe, and nucleation and growth of Ni3Ta, with consequent depletion of Ni in the remaining NiFe, and eventual segregation of Fe.

The differential cross section for hydrogen recoil scattering from helium ions has been determined for energies in the range 1-3 MeV and forward scattering angles of 20, 25, 30 and 35-degrees. Polystyrene (C8H8)n thin films were used as a reference standard, enabling the recoil cross section to be determined with reference to the backscattering cross section for carbon, which was itself newly determined in terms of the simple Rutherford cross section.

Ion beam assisted deposition (IBAD) has been applied to create strongly adhering Au-GaAs interfaces at low temperatures (120–150° C), which display excellent Schottky barrier height and ideality factor. The interface thus created is believed to involve Au-Ga bonding, and its extent is limited to a depth of a few monolayers. The adhesion produced depends critically on substrate temperature and on the arrival rate ratio of Ar ions to Au atoms at the substrate. The mechanism of the interface complex formation is not yet determined; however, it is postulated that surface disorder created by the ion beam contributes critically to enabling the chemical displacement of As by Au at the GaAs surface.