An organic material layer is lithographically patterned to include a linear array portion of lines and spaces. In one embodiment, the organic material layer can be an organic planarization layer that is patterned employing a photoresist layer, which is consumed during patterning of the organic planarization layer. Volume expansion of the organic planarization layer upon exposure to a halogen-including gas causes portions of the linear array to collapse at random locations. In another embodiment, the height of the photoresist layer is selected such that the linear array portion of the photoresist layer is mechanically unstable and produces random photoresist collapses. The pattern including random modifications due to the collapse of the organic material layer is transferred into an underlying layer to generate an array of conductive material lines with random electrical disruption of shorts or opens. The structure with random shorts can be employed as a physical unclonable function.