A package includes an integrated circuit. The integrated circuit includes a first chip, a dummy chip, a second chip, and a third chip. The first chip includes a semiconductor substrate that extends continuously from an edge of the first chip to another edge of the first chip. The dummy chip is disposed over the first chip and includes a semiconductor substrate that extends continuously from an edge of the dummy chip to another edge of the dummy chip. Sidewalls of the first chip are aligned with sidewalls of the dummy chip. The second chip and the third chip are sandwiched between the first chip and the dummy chip. A thickness of the second chip is substantially equal to a thickness of the third chip.