Thermal assessment of copper through silicon via in 3D IC

Thermal management in 3D IC is an important factor in terms of IC performance and reliability. In this study, the feasibility of Cu TSV as a heat dissipation path was experimentally investigated. Si wafers with or without Cu TSV were point-heated at various temperatures and thermal diffusion in the specimens was observed using IR microscope. Si wafers with Cu TSV showed higher top surface temperature than ones without Cu TSV as the heating power increased. This phenomenon was attributed to the preferred heat transfer through Cu TSV in the vertical direction due to high thermal conductivity of Cu. This implies that Cu TSV is an effective vertical heat dissipation path.