As　through-silicon　vias　(TSVs)　are　key　structural　elements　of　3D　integration　and　packaging,　creep　deformation,　which　causes　TSV-Cu　protrusion,　is　critical　for　TSV　reliability.　Here,　the　effect　of　the　diffusion　creep　behavior　on　the　TSV-Cu　protrusion　morphology　is　analyzed　using　experiment　and　simulation.　The　protrusion　morphology　of　TSV-Cu　after　annealing　treatment　is　examined　using　a　white　light　interferometer.　The　diffusion　creep　mechanism　of　TSV-Cu　is　determined　by　observation　of　the　TSV-Cu　microstructure　using　a　scanning　electron　microscopy　and　a　focused　ion　beams.　The　TSV-Cu　grain　size　is　measured　using　an　electron　backscatter　diffraction　system.　The　diffusion　creep　rate　model　of　TSV-Cu　is　deduced　based　on　the　energy　balance　theory　and　is　introduced　into　the　finite　element　model　to　clarify　the　influence　of　diffusion　creep　on　TSV-Cu　protrusion.　It　is　determined　that　the　diffusion　creep　of　TSV-Cu　is　mainly　caused　by　grain　boundary　diffusion　and　grain　boundary　sliding.　The　diffusion　creep　strain　rate　is　positively　correlated　with　the　ambient　temperature　and　the　external　load　but　negatively　correlated　with　the　grain　size.　The　amount　of　TSV-Cu　protrusion　increases　with　decreasing　grain　size.　The　simulation　results　show　that　the　＂donut＂-shaped　protrusion　morphology　is　more　likely　to　occur　in　TSV-Cu　with　smaller　grain　sizes　near　the　sidewall　region　of　the　via.