A test structure for an integrated circuit device includes one or more experiments selectively configured to receive one or more high-speed input signals as inputs thereto and to output at least one high-speed output signal therefrom, the one or more experiments each including two or more logic gates configured to determine differential delay characteristics of individual circuit devices, at a precision level on the order of picoseconds to less than 1 picosecond; and wherein the one or more sets of experiments are disposed, and are fully testable, at a first level of metal wiring (M1) in the integrated circuit device.