Test structure, failure positioning method and failure analysis method

The invention provides a test structure, a failure positioning method and a failure analysis method. The test structure comprises two comb-shaped structures; the comb-shaped structure comprises a comb back substructure and a plurality of comb tooth substructures, the comb tooth substructures extend in the first direction and are arranged at intervals in the second direction, and one ends of the comb tooth substructures are sequentially connected with the comb back substructure; the comb tooth sub-structures in the two comb-shaped structures are arranged in a mutually interpenetrating manner; each comb tooth substructure comprises an active area, and different ions are injected into the active areas in the two comb structures respectively, so that the CT in the different active areas in the normal state has brightness difference in the voltage contrast image. According to the configuration, different ions are injected into the active areas of the two comb-shaped structures, so that the CTs which are respective