Patent ID: 7807566

Claim:
A method for determining conditions for forming a cured dielectric SiOCH film subjected to wet etching, comprising: (i) forming a cured dielectric SiOCH film on a substrate by using at least a silicon-containing hydrocarbon gas having a crosslinkable group and a porogen gas and applying RF power to deposit a dielectric SiOCH film, and curing the dielectric SiOCH film, under conditions including a susceptor temperature, a distance between upper and lower electrodes, an RF power, and a curing time; (ii) evaluating the conditions using a ratio of Si—CH3 bonding strength to Si—O bonding strength of the cured film as formed in step (i); (iii) if the ratio is less than 2.50%, changing the conditions by at least decreasing the curing time to increase the ratio while substantially maintaining the dielectric constant of the film when cured in order to increase wet etching stability, wherein a change of dielectric constant and a change of thickness of the cured film are decreased before and after the cured film is subjected to wet etching, and in order to adjust the dielectric constant (k) of the cured film to satisfy 2.4<k<2.6, and the elastic modulus (EM) of the cured film to satisfy 8 GPa<EM; and (iv) repeating steps (i) to (iii) if the ratio is lower than 2.50%.