Characterization of the Thermal Reactions for Cu/Thermal SiO[sub 2] and Cu/Hydrogen Silsesquioxane on Silicon

Thermal reactions of sputtered Cu films on the thermally grown silicon dioxide and spin-on hydrogen silsesquioxane (HSQ) layers are investigated by examining the sheet resistance, surface microstructure, phase formation, and compositional depth profiles of Cu/thermal and Cu/HSQ structures on Si wafers after annealing in vacuum at The sheet resistance values of both samples decreased after annealing at The decrease in sheet resistance occurred in conjunction with growth of Cu grains and annihilation of microcracks of the as-deposited Cu films. was first found in the Cu/HSQ/〈Si〉 samples after annealing at After annealing at the whole copper layer of Cu/HSQ/〈Si〉 sample reacted with oxygen to form several copper oxides. On the contrary, only a minor part of copper in Cu/thermal structure was transformed to after annealing at The reaction and/or diffusion characteristics of the two structures upon vacuum annealing are discussed.