According to the present invention, there is disclosed a thermal detection device and method of using the device for characterizing and monitoring the dependence of pattern density on thermal absorption of a semiconductor. One or more of the devices can be disposed on a die of a test wafer. The thermal detection device comprises a silicon substrate having a test structure located substantially in the center of the silicon substrate. Frame shaped structures of polysilicon, silicon and oxide, in various configurations, form a collocated arrangement on the silicon substrate. The test wafer is subjected to a rapid thermal process and the resistance of the at least one testing structure is measured and the measured resistance of the at least one test structure is tabulated to a thermal absorption value of the at least one die.