Tsuneji Suzuki

Cu-Oxide-Assisted Selective Pyrolysis of Organic Nanolayer on Patterned SiO2–Cu Surface

Organic nanolayers attract much attention for the isolation and adhesion promotion of the Cu line and insulator in Cu interconnection of microelectronic devices. This paper proposes a strategy for selective formation of adhesion nanolayer on the insulator surface with etching it on Cu surface by Cu-oxide-assisted pyrolysis. After deposition of a uniform polyelectrolyte layer on both SiO2 and Cu surfaces, heat treatment at 350 °C in ambient nitrogen was applied. Then, a larger thickness decrease was observed on the polyelectrolyte layer on Cu when compared to that on SiO2. According to the TDS and XPS analysis, the polyelectrolyte layer was relatively stable on SiO2 up to the intrinsic decomposition temperature of the material, but on the Cu surface it decomposed to volatile small molecules at a lower temperature due to Cu2O-assisted oxidization. This substrate dependent selective pyrolysis was examined for 100 nm width Cu lines and SiO2 spaces, and then a patterned polyelectrolyte layer on the SiO2 surface was obtained with a single nanometer scale edge resolution.

Selective formation of an ultra-thin pore seal on mesorporous low-k for a copper dual damascene structure

A strategy for the selective formation of a pore sealing layer on mesoporous low-k applicable for a Cu dual damascene interconnection process is herein proposed. An ultra-thin, adhesive, and conformal pore sealing layer was formed on mesoporous low-k by spin coating macromolecules. The pore sealant on the Cu surface was selectively decomposed with the help of Cu2O induced oxidization. This selective removal was also examined for patterned structure. Our simple and novel technique will help the integration of ulta-low-k materials in LSI devices.