Transient thermal study of semiconductor devices

An analytical, three-dimensional transient temperature solution of a two-layer semi-infinite plate structure with embedded hear sources is derived. The thickness of the second layer is assumed to extend to infinity. By incorporating the method of images, this solution can be used to approximate the structure with finite second-layer thickness. Exact temperatures can also be obtained for the rectangular lateral boundaries by the use of method of images. The derivation of the solution is verified by comparison with the steady-state temperature solution. A computer program has been written based on the solution and the method of images. A variety of device structures have been studied. Results for the thermal rise time and the effect of the second-layer medium are discussed. The software developed is particularly useful for devices operating under pulsed conditions or switching conditions