Analytical and experimental studies are performed on the electrical potential drop method for monitoring the properties of a surface crack. Integral formulas for potential drops for direct currents are derived by applying Green's theorem to the Laplace equation governing potential drop behaviour. Based on these formulas, a simple non-destructive method is proposed for evaluating the depth of a surface half-elliptic crack and for calibrating potential drop behaviour. The validity and applicability of this method are assessed through the comparison of analysis and experiment.

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The strain state and thermal stability of strained-Si-on-insulator (sSOI) substrates fabricated by the Smart Cut Ò technique were precisely analyzed by X-ray diffraction reciprocal space mapping and Raman spectroscopy. It was demonstrated that the strain was well maintained even after annealing at temperatures up to 1120 C in spite of the thickness being larger than the critical thickness. The strain reduction of only 10% was observed at 1150 C, but the surface smoothness with the RMS roughness below 0.2 nm and high crystal quality did not change. This indicates the high applicability of sSOI to the current Si processes.

A double-layer pattern transfer technique has been developed for submicron aluminum patterning. The double-layer consists of an electron beam resist and an inorganic material ’’spacer’’ having high resistance to reactive ion etching of aluminum. When plasma-deposited silicon dioxide is used as a spacer, severe side-etch of aluminum occurs. On the other hand, by using plasma-deposited silicon nitride as a spacer, submicron aluminum patterns are formed without any etch bias. On profiled surfaces, aluminum patterns with 0.75 μm lines and 0.75 μm spaces are produced without linewidth variations due to the surface topography, by applying etch-back technique to the silicon nitride spacer before resist coating.

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