PROCESS DEVELOPMENT OF LOW RESISTIVE Ag-BASED THROUGH SILICON VIAS USING INKJET PRINTING TECHNIQUE FOR 3D MICROSYSTEM INTEGRATION

Abstract

This paper presents an inkjet printing and filling process to produce 250 mu m deep Ag-based fully filled through silicon vias with the aspect ratio of via depth vs. diameter up to 5. With the optimization of the printing pattern, humidity control, and silver mirror reaction, the Ag TSV subjected to 400 degrees C thermal anneal for 60 mins can exhibit a resistivity of 26 mu Omega.cm, the lowest resistivity and highest AR ever reported. Process simplicity and no need of metal liners make the technique with great potential for 3D microsystem integration.