An integrated circuit device includes an integrated circuit formed in a semiconductor die and an integrated circuit package containing the semiconductor die. The integrated circuit package includes a thermal interface material substantially between the semiconductor die and a heat spreader of the integrated circuit device for conducting heat from the semiconductor die to the heat spreader. The thermal interface material includes diamond particles and has a thickness selected to reduce capacitance between the semiconductor die and the heat spreader over that of a conventional integrated circuit device without reducing the rate of thermal conduction from the semiconductor die to the heat spreader. As a result, the integrated circuit device has improved electrostatic discharge immunity.