Correlation of Thermal Rise Time to Sample Depth in Multi-Die Stacked Devices

Dynamic Digital Modulation, an adaptation of Lock-In Thermography, has been shown to be a useful technique to establish the relative Z-depth of thermal sources in integrated circuits. In order to determine the specific depth of a thermal source it is necessary to correlate known depths to measured thermal rise time. In this work, multi-die stacked memory devices are used as calibration sources to correlate a thermal source at individual die to the measured thermal rise time.