Net-Shape-Based Automated Detection of Integrated-Circuit Layout Plagiarism

Plagiarism of integrated-circuit (IC) layout is a problem encountered both in academia and in industry. A procedure was proposed that compares IC layouts based on the physical representation of particular electrical nets, i.e., on the shape of the features drawn on conducting layers (metals and polysilicon). At the heart of this method is the Needleman–Wunsch algorithm, used for decades in tools aligning sequences of amino acids or nucleotides. Here, it is used to quantify the visual similarity of nets within the pair of layouts being compared. The method was implemented in Python and successfully used to identify clusters of similar layouts within two pools of designs: one composed of logic gates and one containing operational transconductance amplifiers.