Elsevier, Microelectronic Engineering, 3(87), p. 421-425
DOI: 10.1016/j.mee.2009.07.002
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During first metal level interconnects fabrication, a controlled modification of the electro-deposited copper over-deposition (overburden) is performed using a partial chemical–mechanical polishing (CMP) step. Next, copper microstructure is stabilized with a short duration hot-plate anneal. Overburden is then removed during CMP end-of-step. Ionic microscopy and EBSD observations of overburden thickness reduction reveal that copper grain growth occurs differently, according to patterned geometries and with a strong (1 1 1) texture, as observed in modified films. Reduction of overburden thickness also reveals the capacity of anneal temperature to impact electrical performances. Reliability is impacted for thinnest wires.