1. A method of hybrid hotspot detection, executed by at least one processor of a computer, comprising: receiving data of layout patterns of a layout design; classifying the layout patterns as preliminary hotspots, preliminary non-hotspots and potential hotspots based on machine learning; identifying false positives in the preliminary hotspots and false negatives in the preliminary non-hotspots based on pattern patching; and identifying boundary hotspots in the potential hotspots based on process simulation.