Defects in Silicon-Wafers - Characterisation and Prevention

Substrates for highly-complex structural elements of the microelectronical and micromechanical fields of application have to meet a variety of technical requirements, related to their physical, chemical, and geometric properties. Microstructural defects generated by machining and finishing operations can lead to altered characteristics of the substrate and increased part reject rates. In this article, the main defects caused by the steps of wafer processing and finishing are characterised. Their effects on wafer properties are described as well as the equipment required for their detection and evaluation. Finally, methods for defect prevention are shown.