Fabrication for Cu/Hydrogen Silsesquioxane Damascene Structure by Nanoimprint

摘要

[[abstract]]A simple method for Cu/hydrogen silsesquioxane (HSQ) single damascene fabrication without the conventional chemical mechanical polish process was demonstrated. The 100 nm wide Cu nanowires were fabricated by electron-beam lithography and immersion plating with plating bath CuSO4/HF. The resistivity of the Cu nanowires was 4.8–5.3 µ cm after annealing at 400°C for 5 s. The Cu nanowires were transferred onto HSQ by nanoimprint at room temperature with a pressure of 2.2–3.3 MPa. The Cu nanowires were further embedded into the HSQ film to form a Cu/HSQ damascene structure by a simple curing process at 350°C for 10 s. Furthermore, the transferred Cu nanowires were embedded farther in the HSQ film by controlling the curing temperature and time. The topography and cross section of the transferred Cu nanowires on HSQ were examined by a scanning electron microscope. The line-to-line leakage current conduction mechanism of the damascene Cu/HSQ interconnects was studied at various measuring temperatures by a semiconductor parameter analyzer. The phonon-assisted hopping conduction is responsible for the leakage current with a hopping distance of 4.1 Å and a trap level of ~2.87 eV.