US Patent 11935866 Semiconductor device having reduced bump height variation

A semiconductor device includes a first substrate and a second substrate. The semiconductor device includes a plurality of conductive pillars between the first and second substrates. The plurality of conductive pillars includes a first conductive pillar having a first width, wherein the first width is substantially uniform along an entire first height of the first conductive pillar, a second conductive pillar having a second width, wherein the second width is substantially uniform along an entire second height of the second conductive pillar, the first width is different from the second width, and the entire first height is equal to the entire second height, and a third conductive pillar having a third width, wherein the third width is substantially uniform along an entire third height of the third conductive pillar, and the third conductive pillar is between the first conductive pillar and the second conductive pillar in the first direction.