Methods are disclosed for determining a geometrical configuration of an
interconnect structure of a test structure without cross-sectioning or
optical measurements. In one embodiment, the method includes obtaining
simulation data correlating capacitance data, resistance data and
geometrical configuration data for a plurality of interconnect structures
having different geometrical configurations; measuring a capacitance
value and a resistance value from the interconnect structure of the test
structure; and determining the geometrical configuration of the
interconnect structure by comparing the capacitance value and the
resistance value to the simulation data.