Semiconductor chip including a bump structure and semiconductor package including the same

A semiconductor chip includes a substrate having a low-k material layer. An electrode pad is disposed the substrate. A first protection layer at least partially surrounds the electrode pad. The first protection layer includes a first opening at an upper portion thereof. A buffer pad is electrically connected to the electrode pad. A second protection layer at least partially surrounds the buffer pad. The second protection layer includes a second opening at an upper portion thereof. A pillar layer and a solder layer are sequentially stacked on the buffer pad. A thickness of the buffer pad is greater than a thickness of the electrode pad. A width of the first opening in a first direction parallel to an upper surface of the semiconductor substrate is equal to or greater than a width of the second opening in the first direction.