Scanning electron microscopy techniques were used to observe the effects of various treatments on human enamel surfaces. A two-stage model, ie, one stage concerned with the initiation of attack and another stage to describe the directionality of the spread of attack, is presented to explain the effects of the various demineralization treatments.

We present results on structural and compositional changes in GexSe1-x chalcogenide glasses under Ar+ ion irradiation as a function of fluence and ion energies. Energy dispersive X-Ray spectroscopy (EDS) data obtained in this paper shows that the interaction with ions results in the loss of Ge atoms in Se-rich films. The compositional changes affect the structure of the films, which was manifested in differences observed in the Raman spectra. Ion interaction with of the films at the studied energies does affect the surface properties. Simulation of the penetration depth of the ions using Transport of Ions in Matter (TRIM) software shows that the interaction of incident Ar+ ions with the chalcogenide glass occurs within the top 5-nm film thickness, with an etch rate for 450-eV ion energy of approximately 5 nm/s. We suggest the application of this effect for the formation of Redox Conductive Bridge Memory (RCBM) device arrays for which electrical characteristics are presented and discussed

-In this work a scheme for fabricating a conductive bridge non-volatile memory arrays, using ion bombardment through a mask, is demonstrated. Blanket films and devices have been created to study the structural changes, surface roughness and device performance. Ar + ions interaction on thin films of Ge x Se 1-x system have been studied using Raman Spectroscopy, Atomic Force Microscopy (AFM) and Energy Dispersive X-Ray Spectroscopy (EDS). The performance of the memory devices has been analyzed based on the formation of vias and damage accumulation due to Ar + ion interactions with Ge x Se 1-x (x=0.25, 0.3 and 0.4) thin films of chalcogenide glasses (ChG). This method of devices/arrays fabrication provides a unique alternative to conventional photolithography for prototyping redox conductive bridge memory without involving any wet chemistry.

Phone: þ1 208 426 1319, Fax þ1 208 426 2470This work focuses on the study of Ge rich phases in the Ge-Se chalcogenide glass system. Radiation induced effects particularly related to Ag diffusion in the glasses under the influence of different doses of g radiation are investigated and documented. Raman spectroscopy, X-ray diffraction, energy dispersive X-ray spectroscopy, scanning electron microscopy, and atom force microscopy confirmed the occurrence of radiation-induced Ag diffusion and oxidation of the hosting chalcogenide thin films. This causes Ag surface deposition and structural reorganization of the hosting backbone, and affects the electrical performance of the films. It is suggested that the sensing ability of the thin films can be substantially influenced by the encapsulating the sensing elements to avoid the oxidation of the chalcogenide film.

Among the many applications of chalcogenide glasses, their involvement as an active layer in redox-conductive-bridge-memory (CBRAM) devices triggers particular interest because of their potential to replace CMOS-based NAND and flash memory. In these devices the chalcogenide glass film is in contact with a silver film, and it is of a practical interest to understand how a beam of protons can influence this dual layer structure in order to identify how the performance of the CBRAM devices will be affected. In this work we studied the influence of proton beam irradiation over a Ge 40 Se 60 /Ag film stack. Various methods of analysis including scanning atomic force microscopy (AFM), Raman spectrometry, Rutherford backscattering spectrometry (RBS), X-ray diffraction (XRD), and X-ray photoelectron spectrometry (XPS) have been applied to study the structure, topography, composition, bonding configurations, diffusion kinetics, and molecular evolution of thin films related to the active sections of CBRAM devices, and quantitative analysis of material parameters and changes is reported. The results reveal silver surface deposition and germanium oxidation, as well as change in the films chemistry as a result of proton irradiation.