CVD of copper using copper(I) and copper(II) β-diketonates

Abstract

Reaction paths for the chemical vapor deposition (CVD) of copper from (hfac)Cu(vtms), Cu(hfac) 2, and Cu(fod) 2 were studied using mass spectrometric analysis of the reaction products. Cu(hfac) 2 was identified as one of the products when (hfac)Cu(vtms) reacts with or without hydrogen at temperatures from 130 to 235 °C in a hot-wall batch reactor. Therefore, the route to copper formation is a disproportionation reaction which we found to be reversible under all operating conditions. The reverse reaction regenerates the precursor, (hfac)Cu(vtms). Our experiments show that Cu(hfac) 2 reacts very slowly with H 2 at temperatures below 250 °C, which typically are used for (hfac)Cu(vtms). Therefore, below 250 °C, the deposition rate of copper from (hfac)Cu(vtms) is not increased by the reaction of its product, Cu(hfac) 2, with hydrogen. For CVD using Cu(hfac) 2 and Cu(fod) 2 with hydrogen, Hhfac and Hfod are the reaction products.