Method of detecting failure of a semiconductor device

A method of detecting failure of a semiconductor device includes forming an active fin on an active region of a substrate, the active fin extending in a first direction, forming a gate structure on the active fin, the gate structure extending in a second direction intersecting the first direction, forming source/drain layers on respective portions of the active fins at opposite sides of the gate structure, forming a wiring to be electrically connected to the source/drain layers, and applying a voltage to measure a leakage current between the source/drain layers. Only one or two active fins may be formed on the active region. Only one or two gate structures may be formed on the active fin.