New OMCVD precursors for selective copper metallization

A novel OMCVD process for the highly selective deposition of pure, adherent, low resistivity copper films onto conductive substrates is described. Central to this process is a new volatile liquid copper⁺¹ precursor, Cupra Select, designed to thermally disproportionate at low temperatures to cleanly give copper metal and volatile non-corrosive by-products. Thus, selective depositions onto metallic versus insulating dielectric substrates are achieved between 120 to 420°C with growth rates in excess of 100 nm/min and grain sizes as low as 0.1 microns. In addition, a novel complementary copper etching process is discussed that is chemically compatible with the copper CVD chemistry