Experimental Investigations on Magnetic Field Assisted Abrasive Micro Finishing of Austenitic Stainless Steel 304L

This paper presents the experimental investigations on magnetic field assisted abrasive finishing of SS304L flat work material. The experiments are designed using Taguchi design of experiments method. The results indicate that process parameters such as voltage and machining gap are significant on improvement of surface finish (∆Ra). The surface roughness value as low as 0.09 µm is achieved at optimum conditions. The surface topography of the work material is analyzed by means of the surface roughness profile, optical and atomic force micrographs.

Optical Properties of Sputtered Silver Granular Films

In this research we study optical absorption and morphology of silver films prepared with a sputtering method. Silver granular films are obtained on a glass substrate for films with thickness smaller than about 60 Å. Superficial silver clusters of around 100 nm in diameter are clearly seen in the atomic force micrographs. The absorption of these samples are characterized by plasmon excitation in the 450-650 nm spectral range, which differs from the known excitation of silver nanoparticles fabricated by different techniques. The optical absorption of silver granular films depend on sputtering conditions like substrate temperature or deposition rate and correlates with the surface morphology.

Analyzing Atomic Force Micrographs Using Spectral Methods

ABSTRACTMicroroughness is a critical parameter in ULSI device interface reliability and has been shown to effect several critical MOS electrical properties. The atomic force microscope (AFM) has become the instrument of choice for silicon surface microroughness analysis. The parameters usually specified to characterize roughness are average and root mean square roughness. However, these parameters are spatial averages and can have the same value for two significantly different surfaces. Spectral analysis using the Fast Fourier Transform (FFT) has been applied as a powerful tool to analyze AFM data by looking at roughness as a function of spatial wavelength. The Fast Hartley Transform, being a real transform, is faster than the FFT and is better suited for this analysis. It has been used here to derive spectral information from the AFM height data. Before evaluating the transform, cancellation of any tilt or warp in the AFM data is done to remove frequency components which interfere with other spectral information. A PC-based computer program to determine the transform and its magnitude will be described. The application of this method to analyze data from Si and SiO2 surfaces as a function of pre-oxidation cleaning chemistry will be presented. Significantly better insight into the spatial distribution of roughness is obtained, when compared to previous implementations.