No abstract

Porous ultralow dielectric film pores were sealed by 1 -5 nm films of boron carbonitride, itself a dielectric. The BC 0.9 N 0.07 films were deposited by chemical vapor deposition at 335°C on etched and ashed blanket films and patterned films of porous methyl silsesquioxane ͑PMSQ͒. The penetration of Ta through the boron carbonitride film and into the porous low substrate following exposure to TaF 5 at 230°C, or TaSi x growth from TaF 5 and Si 2 H 6 at 230°C, was used to test pore sealing. Tantalum profiles were evaluated using x-ray photoelectron spectroscopy depth profiling, back side secondary ion mass spectroscopy, and energy dispersive x-ray spectroscopy. A 3.9 nm boron carbonitride film sealed PMSQ, which has an average pore diameter of 1.9 nm before etching. The diffuse nature of the BC 0.9 N 0.07 -PMSQ interface in electron energy loss profile maps suggests that some of the BC 0.9 N 0.07 penetrates into the PMSQ until the pore openings are pinched off as the sealing film deposits.