A new approach for Cross-Sectioning Sem Specimens of Semiconductorsby Broad-Ion Beam Milling

Extract

The cross-sectioning of semiconductor wafers for SEM studies has traditionally been carried out by tedious and laborious mechanical grinding and polishing techniques. The mechanically polished surfaces are treated using a “wet chemical” etching method to enhance and delineate certain features or layers in a given specimen. The etched specimens are then coated by conductive layers to prevent charging during SEM examination. As an alternative to “wet chemical etching”, broad-ion beam etching techniques have been developed for surface treatment of mechanically polished specimens. More specifically, we have reported [1] the utilization of a combined process of broad-ion beam etching and coating of mechanically cross sectioned semiconductors in a single vacuum chamber. As a further progress to that work, we report a rapid and reliable technique for preparing precision SEM cross sections. The technique is based on perpendicular broad-ion beam milling of cleaved wafers to expose any desired cross-section through a given feature of the specimen.