in this work, chemical vapor deposited low-k films using tetra methyl tetra cyclo siloxanes (TMCTS) precursors were studied. Process parameters studied included low-frequency RF (LFRF) power, high-frequency RF (HFRF) power, pressure, CO2 flow rates, and precursors flow rate. Results indicated that the reduction of LFRF power, CO2 flow rate, and increase in HFRF power, pressure, TMCTS flow rate reduces the dielectric constant (k). In the TMCTS flow rate, there are two reaction's mechanisms which are mass transport-limited and reaction-limited that govern the reaction at low flow rate and high flow rate of TMCTS, respectively. Oxygen in the process plasma played a major role in breaking the Si-CH3 and Si-H bonds and forming a silica-like structure having higher k. It was found that the k as inversely proportional to the Si-CH3/Si-O ratio and having a linear relationship with hardness and modulus. The low-k films demonstrate good stability and good adhesion property. (C) 2004 Elsevier B.V. All rights reserved.