Fabrication of fine copper lines by selective chemical vapor deposition onsilicon substrates

Fine copper lines, with a width of less than 1 mum, were fabricated on sili con substrates. For the fabrication, oxidized (100) silicon substrates were used, covered with a film grown by LPCVD at 0.1 Torr and 550 degreesC from W(CO)(6) decomposition. These substrates were subsequently covered with AZ 5214 (TM) photoresist, 1.15 mum thick, patterned so that lines and trenche s with width below 1 mum 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 substrate s by 1,5-cyclooctadiene-Cu(I)-hexafluoroncetylacetonate decomposition, at 1 Ton and temperatures of 110 and 140 degreesC. In all cases copper was sele ctively 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 140 deg reesC, respectively). After depositions the photoresist was removed in oxyg en plasma leading to the formation of fine copper lines. (C) 2001 Elsevier Science B.V. All rights reserved.