Manganese oxide formed by a chemical vapor deposition (CVD) method is a promising candidate for an ultrathin diffusion barrier layer in the interconnect structure of advanced semiconductor devices. This study placed emphasis on the adsorbed moisture in a hydrophilic SiO2 substrate and investigated the effects of the adsorbed moisture on the formation behavior, structure and composition of the CVD Mn oxide layer. The SiO2 substrates were preannealed at 150 to 500 °C for 1 h to control the type and amount of the residual adsorbed moisture. A Mn oxide layer was subsequently deposited by thermal CVD of bis(ethylcyclopentadienyl)Mn at 200 °C for 30 min. The Mn oxide layer deposited on an as-received substrate was composed of the bilayer of crystalline MnOx and amorphous MnSixOy. The Mn oxide layer deposited on a preannealed substrate was composed of the single layer of amorphous MnSixOy. The crystalline MnO x layer was formed by the reaction of the Mn precursor with physisorbed moisture on the as-received SiO2. The amorphous MnSi xOy was due to the reaction with chemisorbed moisture on both the as-received and the preannealed SiO2. Results of the present work indicate the importance of controlling the adsorbed moisture of the substrates in order to obtain a Mn oxide layer with desired structure and thickness as a diffusion barrier layer.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films