In various embodiments of the present invention, tunable resistors are
introduced at the interconnect layer of integrated circuits in order to
provide a for adjusting internal voltage and/or current levels within the
integrated circuit to repair defective components or to configure the
integrated circuit following manufacture. For example, when certain
internal components, such as transistors, do not have specified
electronic characteristics due to manufacturing defects, adjustment of
the variable resistances of the tunable resistors included in the
interconnect layer of integrated circuits according to embodiments of the
present invention can be used to adjust internal voltage and/or levels in
order to ameliorate the defective components. In other cases, the tunable
resistors may be used as switches to configure integrated circuit
components, including individual transistors and logic gates as well as
larger, hierarchically structured functional modules and domains.