Effect of thermal treatment on carbon-doped silicon oxide low dielectric constant materials

Abstract

Carbon-doped silicon oxide (SiOCH) low dielectric constant (low-k) material is a good candidate for advanced interconnect technology. Good thermal stability of the dielectric is required due to the many thermal processes involved during IC fabrication. The thermal stability of tetramethylcyclote-trasiloxane (TMCTS) based plasma-enhanced chemical vapor deposition (PECVD) carbon doped IOW-k material with annealing temperature from 400 to 800 °C in N 2 was studied. The thermal stability temperature of TMCTS based carbon doped low-k material is 600 °C. Above 600 °C annealing, the thermal energy can break Si-CH 3, Si-C, Si-H, and C-H bonds leading to outgasing, which results in film composition change, weight loss, and thickness shrinkage. Film composition changes, especially carbon loss and oxygen incorporation, can degrade its reliability extremely. Carbon is desorbed in the form of CH 4, CO, and other hydrocarbon. Copyright © 2005 American Scientific Publishers All rights reserved.