Study on the 12 in. wafer uniformity of high aspect ratio TSV filling by using rotation cathode

Abstract

In 2.5/3D(2.5/3-dimensional) packages, TSV (Through-Silicon Via) technology is crucial for achieving high performance and low power consumption. However, there are still challenges when it comes to uniformly filling TSVs on 300 mm whole wafers without defects. This study focuses on addressing this issue by designing a rotating cathode carrier with a 300 mm diameter, simulating the plating environment in different areas of a 300 mm wafer. The effects of plating conditions, such as cathode rotational speed and chip mounting position, on the filling of TSV are investigated. The TSV have a hole diameter of 10 μm and a depth of 100 μm.The findings reveal that when the cathode carrier rotates at a speed of 30 rpm, different areas of the analog wafer exhibit complete filling of TSV. Additionally, a surface plating layer with an average thickness of approximately 3 μm is obtained.