A technique was developed for the preparation of transparent, thin film epoxy samples for direct TEM investigation of the activation of epox:r and the initiation of the electroless Cu reaction. Associated EDX measurements determined the composition of the nucleated Cu particles. The steps of activation with a Pd-Sn colloidal catalyst, acceleration with NaOH, HC1, or EDTA, and initiation of electroless Cu plating were studied individually. All of the accelerators were effective in removing tin from the surface and increasing the initial rate of Cu deposition. The Cu distribution on the epoxy was determined by the accelerator, with NaOH and EDTA giving the most uniform distributions.

C-V HYSTERESIS INSTABILITY 2813deed important to the investigation of the radiation effect on tantalum oxide-based devices, and should be carefully considered when one is interpreting the interface charges from C-V curves.

THIN CoP FILMS 2817 anisotropy, was found not to be the cause of the high Ho and S*. Rather, high Hc and S* were associated with shape and strain anisotropies of the CoP crystallites. A mechanism for the origin of shape anisotropy in the NaOH-pretreated samples is suggested to be the nonuniform oxidation of the NiP substrate, followed by nucleation of CoP in the channels where this oxide was thinnest and was first removed in the electroless plating solution. Under constant plating bath conditions, the structure and magnetic properties of the CoP are extremely dependent on the substrate treatment. In obtaining good magnetic films, substrate pretreatment can be as important as, if not more important than, the plating parameters. AcknowJedgmentsMany helpful discussions with Dr. J. Horkans are gratefully acknowledged. ABSTRACTElectroless CoP films were deposited on NiP substrates that had been subjected to a variety of surface treatments. The interface between the CoP and NiP was then examined using Auger sputter-etch profiling, Rutherford backscattering, and secondary-ion mass spectrometry. The composition of the interface varied markedly with the NiP pretreatment. There was no detectable O incorporation in the structure when the NiP underwent chemically reducing pretreatments. A NaOH pretreatment of NiP resulted in substantial O incorporation at the CoP-NiP interface. Interfacial oxygen was generally present when there was inhibited CoP nucleation leading to magnetic films with high shape anisotropy and good magnetic properties. The source of the interfacial oxygen was the pretreatment step, rather than the initial stages of the CoP deposition. At least some of the interfacial oxygen may have been incorporated as a hydroxide. There is also mobile H in the structure, presumably arising from the electrotess plating processes. ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 35.8.191.249ABSTRACT Experimentally there appears to be a limit to the size of isolated patterns of electrocatalytic nuclei below which electroless metal deposition does not occur. From a model of electroless deposition on small isolated circular spots we conclude that this inhibition effect is caused by an enhanced supply of oxygen to small patterns due to nonlinear diffusion of dissolved oxygen. Since generally the kinetically determined rate of oxygen reduction is larger than that of oxidation of the reducing agent, the open-circuit potential of nuclei in small patterns cannot be shifted to a sufficiently negative value at which metal deposition is initiated. At relatively large substrates with a high density of small patterns this so-called oxygen-diffusion-size effect may not be noticed since the supply of oxygen is limited by linear diffusion to an effectively planar substrate.) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 35.8.191.249 Downloaded on 2015-04-05 to IP