화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.153, No.6, G539-G542, 2006
Highly conformal deposition of pure Co films by MOCVD using Co-2(CO)(8) as a precursor
Highly conformal Co thin films were deposited on SiO2 trenches with an aspect ratio of 13 by metallorganic chemical vapor deposition (MOCVD) using Co-2(CO)(8) as a precursor in a low-temperature regime of 50 - 70 degrees C where the growth rate was 3.5 - 7.0 nm/min. Lowering the pressure of the process reduces the number of collisions in the gas phase and, thus, widens the temperature regime in which the surface reaction controls the growth rate. A processing pressure of 26.7 Pa (0.2 Torr) allows for conformal deposition only at 50 degrees C, whereas deposition at a reduced pressure of 4.0 Pa (0.03 Torr) widens the temperature regime (50 - 70 degrees C) in which excellent conformality can be obtained. The conformal Co thin film, produced at 50 degrees C and 4.0 Pa, showed a resistivity of 10 - 12 mu Omega cm and contained 1.0 atom % oxygen and less than 1.0 atom % carbon. After annealing this film at 600 degrees C, its resistivity was reduced to 6 mu Omega cm, which is close to the bulk resistivity (5.7 mu Omega cm) of Co. Therefore, this low-temperature process, which allows for the excellent conformal deposition of pure Co films, can be utilized to produce silicided contacts for advanced devices which require a low contact resistance and good electrical performance. (C) 2006 The Electrochemical Society.