A novel manufacturing scheme for TSVs with porous polymer insulation liners
In this paper, a novel manufacturing scheme based on heat-depolymerizable material and thermosetting material is proposed to achieve high performance through silicon vias (TSVs) with porous polymer insulation liners. In order to strengthen the mechanical reliability and guarantee the low capacitance and low thermal expansion stress of TSVs, we come up with the novel TSVs with porous polymer insulation liners. And we present a manufacturing scheme for the porous polymer insulation liners. The polymer adopted in the manufacturing scheme is the mixture polymer of heat-depolymerizable material Polyimide (PPC) and thermosetting material Polyimide (PI). To address the challenge in fabrication of porous polymer liners in high aspect-ratio TSVs, we have adopted a vacuum-assisted spin-coating technology for filling the mixture polymer (PPC&PI) in high aspect-ratio annular trenches. Finally, through initial pre-cure and eventual pyrolysis, the porous structure can be achieved.