Optimizing Aluminium/Silicon Temperature Gradient Zone Melting Process for Power Device Periphery

Thermomigration is an attractive alternative to produce through-wafer isolation walls used for planar technology power devices such as thyristors/triacs. However, a few defects occur during the thermomigration process, such as beads or discontinuities in the aluminium lines. As these defects are causally related to thermal uniformity, a new calculation method to evaluate the homogeneity of thermomigration annealing has been demonstrated. Furthermore, this article discusses the impact of pattern design and pre-annealing before thermomigration.