Effects of C2H5I Catalyst on the Property of Cu Chemical Vapor Deposition

• Main Authors: Wang, An-Chih, 王安志
• Other Authors: Chen, Mao-Chieh
• Format: Others
• Language: en_US
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/3ygh54

碩士 === 國立交通大學 === 電子工程系所 === 92 === This thesis studies of the effects of C2H5I catalyst on the copper chemical vapor deposition (Cu CVD), including Cu nucleation, Cu film property, and via-filling capability, using a liquid metalorganic compound of Cu(hfac)TMVS with 2.4 wt% TMVS additive as the precursor. Sputter-deposited TaN was used as the substrate for the Cu CVD and the vapor phase C2H5I was used for TaN surface treatment prior to the Cu CVD. The substrate pretreatment by C2H5I enhanced the adsorption of Cu species on the substrate surface, reduced the incubation time of nucleation, and thus accelerated the Cu film formation. The wetting angle of Cu grains nucleated on the C2H5I-treated TaN substrate surface was larger than that nucleated on the control TaN substrate (63o vs. 94o), presumably due to the increase of substrate surface energy and/or the decrease of Cu/substrate interfacial energy. The Cu films deposited on the C2H5I-treated TaN substrate all exhibited higher growth rate and lower electrical resistivity; however, they all exhibited a lower intensity peak ratio of Cu(111) to Cu(200) reflections and a degraded adhesion to the TaN substrate. Post-deposition thermal annealing at 400oC in N2 ambient was able to further reduce the film resistivity and surface roughness. Via-filling capability of Cu CVD by using vapor phase C2H5I substrate pretreatment did not exhibit an obvious improvement. However, it was found that notable improvement in via-filling capability of Cu CVD can be achieved at low deposition temperature, low deposition pressure, and high concentration of precursor species in the gas phase of CVD.