Properties of boron carbon nitride (BCN) film after plasma ashing

Dry etching and resist ashing of a low dielectric constant interlayer (low- k) are required for the formation of a trench structure, which is necessary for the fabrication of damascene interconnections using materials such as Cu. We investigated the properties of boron carbon nitride (BCN) film after plasma ashing by H 2/N 2 gas and O 2 gas and compared with porous SiOC (P-SiOC) thin film. It is found that by ashing with O 2 or N 2/H 2 plasma, BCN film composition does not change and the film damage is also little in the view points of leakage currents and dielectric constant. Hence, it is understood that both N 2/H 2 or O 2 gas plasma can be used for interconnection process of with BCN low- k film.