Observation of Parallel Arrays of Pure Edge Dislocations in Silicon

A four-point bending technique is used to plastically deform silicon slices. The silicon samples are oriented so that the resolved shear stress is greatest along a single family of (111) crystallographic planes. The operation of a single slip system is observed both optically and with a scanning electron microscope when bending is done at temperatures greater than 1000°C. At lower temperatures, multiple slip occurs. Transmission electron microscopy shows the dislocations to be arranged in parallel arrays where single slip predominates and classifies them as pure edge.