Messung der Festigkeit von dünnen monokristallinen Silizium Wafern

Single-crystal silicon is a key material in the semiconductor industry, where it is used in microprocessors, sensors and solar cells. Mechanical stresses during manufacturing and service, combined with brittle material behavior, lead to a certain risk of failure. To minimize this risk, knowledge of strength parameters is essential. The aim of this thesis is the quantitative determination of the strength of thin wafers made from a silicon single crystal. After dicing the raw wafers into smaller specimens, they were tested using biaxial strength testing methods. Fractographic analyses were used to interpret fracture behavior. Since conventional evaluation models do not account for the elastic anisotropy of single-crystals, a finite element simulation was additionally created. One research question concerns the transferability of strength values between different strength tests and loading scenarios: For example, whether the Weibull concept, including the size effect, can be applied consistently. During the polishing process, grinding marks on the wafer surface get introduced. It will be investigated, if the direction of said grinding marks have a significant influence on strength. This knowledge provides a foundation for evaluating single-crystal brittle materials and could lead to increased mechanical reliability in future component designs.