Patent ID: 7955650

Claim:
A method for obtaining process parameters for controlling a dielectric constant of a cured film, comprising: (i) introducing only a source gas at a flow rate of A, a porogen gas at a flow rate of B, an oxidizing gas at a flow rate of C, and an inert gas into a reaction space in which a substrate is placed, said source gas consisting of a silicon-containing hydrocarbon compound having multiple cross linkable groups including one or more alkoxyl groups, said porogen gas being a gas constituted by a porogen material, C being no less than 10 seem but less than 50 sccm, wherein a ratio of B/(A+B) is used as a parameter for controlling a dielectric constant of a cured film, and is between 0.70 and 0.85; (ii) applying RF power to the reaction space, thereby depositing a film on the substrate by plasma CVD; (iii) curing the film to remove the porogen material, thereby forming pores in the cured film having a dielectric constant k1; (iv) repeating steps (i) to (iii) by changing the ratio of B/(A+B) between 0.70 and 0.85 by an amount R, thereby obtaining a cured film having a dielectric constant k2; and (v) repeating steps (i) to (iii) by changing the ratio of B/(A+B) between 0.70 and 0.85 at a rate of R/(k1−k2) to obtain a cured film having a target dielectric constant, thereby obtaining process parameters for the target dielectric constant.