On combining alternate test with spatial correlation modeling in analog/RF ICs

Statistical intra-die correlation has been extensively studied as a means for reducing test cost in analog/RF ICs. Generally known as alternate test, this approach seeks to predict the performances of an analog/RF chip based on low-cost measurements on the same chip and statistical models learned from a training set of chips. Recently, an orthogonal direction for leveraging statistical correlation towards reducing test cost of analog/RF ICs has also gained traction. Specifically, inter-die spatial correlation models learned from specification tests on a sparse subset of die on a wafer are used to predict performances on the unobserved die. In this work, we investigate the potential of combining these two statistical approaches, anticipating that the performance prediction accuracy of the joint correlation model will surpass the accuracy of its constituents. Experimental results on industrial semiconductor manufacturing data validate this conjecture and corroborate the utility of the combined performance prediction models.