Fabrication of fine copper lines by selective chemical vapor deposition on silicon substrates
Fine copper lines, with a width of less than 1 ?m, were fabricated on silicon substrates. For the fabrication, oxidized (100) silicon substrates were used, covered with a film grown by LPCVD at 0.1 Torr and 550C from W(CO)6 decomposition. These substrates were subsequently covered with AZ 5214 photoresist, 1.15 ?m thick, patterned so that lines and trenches with width below 1 ?m were formed. After development and post bake, the photoresist was treated with three different methods of flood exposure and bake. Copper was then chemically vapor deposited on the patterned substrates by 1,5-cyclooctadiene-Cu(I)-hexafluoroacetylacetonate decomposition, at 1 Torr and temperatures of 110 and 140C. In all cases copper was selectively grown on the tungsten film only. The film had a granular form with a grain size increasing with temperature (150 and 550 nm at 110 and 140C, respectively). After depositions the photoresist was removed in oxygen plasma leading to the formation of fine copper lines.
fine copper lines silicon substrates scvd