Study of SiO_2-films deposited by adding N_2O or O_2 to TEOS in photo-chemical vapor deposition at room temperature

摘要

We have developed a new scheme for SiO_2-film preparation in which tetraethoxyorthosilicate (TEOS:Si(OC_2H_5)_4) is photo-dissociated by vacuum ultraviolet Xe_2 excimer radiation (λ = 172 nm). The SiO_2-films can be deposited at room temperature include a considerable amount of C and H atoms and/or molecules. They show relative-dielectric constant and leakage currents as low as the films prepared with ozone-assisted CVD. We have tried to avoid impurity inclusion by adding O_2 or N_2O to the raw material TEOS. The addition of O_2 results in decrease of C-H inclusion. We have evaluated the electrical properties and gap-filling characteristics by adding the gas. The SiO_2-films prepared with the photo-CVD could be useful for a multi-layer-inter-connection technologies of CMP-less and free environmental disruption at ULSI devices processing.