Contact Damage in Single‐Crystalline Silicon Investigated by Cross‐Sectional Transmission Electron Microscopy

Abstract

Cross‐sectional transmission electron microscopy (TEM) is demonstrated as a powerful tool for investigating subsurface damage in the micrometer and submicrometer ranges in brittle materials, and applications to a wide variety of contact damage in silicon are discussed and illustrated with TEM images. Regions of plasticity and different types of cracking are identified and characterized for various contact situations: indentation, scribing, solid‐particle impacts, and polishing/grinding. Most single‐point contact situations result in similar types of damage in silicon, although transitions between different damage mechanisms occur between different load levels. Normally, the crack geometry is governed by the principal stress directions and is only weakly influenced by the lattice orientation. Grinding with metal‐bonded abrasives results in fairly deep subsurface damage zones, but the main mode of material removal is superficial lateral cracking. Polishing with small‐size free abrasives results in very superficial damage zones and mirror‐like surface finish.