High Frequency Scanning Acoustic Microscopy Applied to 3D Integrated Process: Void Detection in Through Silicon Vias

Among the technological developments pushed by the emergence of 3D-ICs, Through Silicon Via (TSV) technology has become a standard element in device processing over the past years. As volume increases, defect detection in the overall TSV formation sequence is becoming a major element of focus nowadays. Robust methods for in-line void detection during TSV processing are therefore needed especially for scaled down dimensions. Within this framework, the current contribution describes the successful application of innovative GHz Scanning Acoustic Microscopy (SAM) to TSV void detection in a via-middle approach.