Effects of CO2 and O2 on the property of tetra methyl tetra cyclo siloxanes based low-k film

In this work, chemical vapor-deposited carbon-doped oxide (CDO) films using tetra methyl cyclo tetra siloxanes (TMCTS) precursors were studied. Process parameters studied include low frequency RF (LFRF) power, pressure, and CO2/O2 flow rates as the oxidation influencing agents. Numerous properties of the films are studied include dielectric constant (k), breakdown voltage, leakage current, stresses, hardness, modulus, refractive indices, and chemical bonding. Reliability of the films was studied using the autoclave test. Results indicated that reduction of LFRF power, CO2/O2 flow rates, and increase in pressure, reduces the dielectric constant. It is found that O2 has a stronger oxidation effect compared to CO2 gas. It was observed that the CO2-O2 process was able to lower the k value and impart higher hardness and modulus compared with a pure CO2 process