Improving Efficiency and Robustness of Gaussian Process Based Outlier Detection via Ensemble Learning

Although automotive semiconductors must comply with the standard dynamic part average testing (DPAT) defined by the Automotive Electronics Council, it remains challenging to detect outliers that deviate from the spatial trend within a wafer. Outlier detection using Gaussian process (GP) regression has recently been proposed and outperformed DPAT. However, the detection performance degrades when faulty large-scale integrations are densely included in the regression. Furthermore, the applicable test items are limited because of the long computation time for regression. We propose an outlier detection method by applying ensemble learning to GP regression for simultaneously improving the detection performance and shortening the learning time. Experimental results on industrial production test data demonstrate that the proposed method improves the robustness against latent faulty chip detection by 15.6% while reducing the computation time by 98.6% compared with the conventional GP-based method.