Wire-segment holographic test structures for statistical interconnect metrology

Initial results on the use of computer generated holograms for statistical interconnect metrology are presented. The test structures are fabricated using a process easily capable of resolving 1 μm features and consist of arrays of wire segments illuminated with a He-Ne laser. Since the holograms are fabricated at the same times as actual wires on the wafer, the fidelity of the projected image may be correlated with the effects of global process errors. Specifically, this paper presents data on the effect of variations in photoresist exposure time on the intensity of holographic image produced by the test structures. The paper concludes by discussing the experimental requirements for translating this technique into the deep-submicron regime