Copper metallization of hydroxyl-modified amorphous Si:C:H films

X-ray photoelectron spectroscopy (XPS) was used to examine the initial stages of copper deposited by Physical vapor deposition (PVD), or sputter deposition, interacting with amorphous silicon:carbon:hydrogen (a-Si:C:H) films and hydroxyl modified amorphous silicon:carbon:hydrogen (a-Si:C:H/OH) films under Ultra-high vacuum (UHV) conditions. Amorphous-Si:C:H films were formed by condensing vinyltrimethylsilane (VTMS) on a titanium substrate (temperature less than or equal to 90 K) followed by electron beam bombardment (500 eV), and annealing to 300 K in UHV Amorphous Si:C:H/OH films were formed by condensing H2O on the condensed VTMS multilayer (less than or equal to 90 K) followed by electron beam bombardment (500 eV) and annealing to 300 K in UHV The stoichiometry of the unmodified and modified a-Si:C:H films was determined by XPS to be C-4.5:S1 and C-4.3:O-0.44:Si, respectively. XPS measurements of PVD Cu on the modified film at 300 K indicate initial conformal growth with Cu(I) and Cu(0) formation at the Cu/Si:C:H/OH film interface. At higher Cu coverages, only Cu(0) was observed. In contrast, 3-dimensional island formation (Volmer-Weber growth) of Cu(0) was observed on the unmodified film. Annealing both the modified and unmodified films up to 800 K in UHV produced no significant change in the Cu(3p)/Cu(2p(3/2)) intensity ratio, indicating negligible Cu diffusion through the film into the titanium substrate below 800 K. (C) 2003 Elsevier Science B.V. All rights reserved.