Nonplanar silicon surfaces were prepared and oxidized at 900°–1100°C and the oxide morphology was studied by transmission electron microscopy of thin sections. A 30% decrease in oxide thickness at silicon step edges following 900° and 950°C wet oxidation is attributed to the effect of locally compressive intrinsic stress within the oxide on the solubility of oxygen. Oxidation inhibition becomes less at higher temperatures due to the relief of stress (during growth) by viscous flow of the oxide.

Electron emitters in vacuum microelectronic devices need sharp tips in order to permit electron emission at moderate voltages. A method has been found for preparing uniform silicon tips with a radius of curvature less than 1 nm. These tips are formed by oxidation of 5-μm-high silicon cones through exploitation of a known oxidation inhibition of silicon at regions of high curvature.

Sharp microtips of silicon have potential applications as field emitters and as electrical or mechanical microsensors. This study describes a single unified etching/oxidation treatment that results in uniform tips with controlled radii of atomic dimensions or larger. Variations in the etching/oxid~ti.o~ treat~ent for~ I?ultiple tips with two or four tips per etched pyramid, which offe~ t.h~ possIbil.lty of higher emlss~on current density for field emitter applications, and higher sensltivlty for rmcrosensor applicatlOns.

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Special techniques have been developed for routine preparation of transmission electron microscope samples from integrated circuit devices. These methods, which are described and illustrated in this paper, are the preparation of replicas of fractured multilayer structures, vertical cross sections, horizontal cross sections, and feature enhancement on cross-section samples through the use of special staining and etching treatments.