A semiconductor package includes a first semiconductor chip mounted on the package substrate, a second semiconductor mounted on the package substrate and set apart from the first semiconductor chip in a horizontal direction thereby forming a gap between the first semiconductor chip and the second semiconductor chip. The semiconductor package further includes a first thermal interface material layer formed in the gap and having a first modulus of elasticity and a second thermal interface material layer formed on each of the first semiconductor chip and the second semiconductor chip and having a second modulus of elasticity, wherein the first modulus of elasticity is less than the second modulus of elasticity.