Computational Analysis of the Effects of Nanoscale Confinement on the Structure of Low-k Dielectric Hybrid Organosilicate Materials

Abstract

Emerging interconnect technologies with increased performance of microchips necessitate the reliable integration of ultra-low-k dielectrics such as hybrid organosilicate glasses (OSG) as insulating units to prevent crosstalk. However, obtaining nanoscale trench patterns densely filled with low-k dielectrics has been challenging as the feature sizes become smaller. Several studies report on the formation of undesired low-density regions within the low-k dielectric decreasing device reliability and preventing easy scalability. With the help of molecular dynamics simulations, we developed computational modeling strategies where we explore the role of OSG precursor structure and the OSG precursor-trench interaction on the formation of low-density regions and final morphology of the low-k filling under confinement. Our goal is to ultimately provide guidance for the experimental efforts for precursor selection to control the formation of low-density regions to enhance mechanical reliability. Our simulation results show that cyclic and hyperconnected 1,3,5-benzene precursor molecules can pack in a relatively more homogeneous fashion under nanoscale confinement compared to more conventionally connected ethylene bridged Et-OCS molecules. The molecular geometry and crosslinking of hyperconnected 1,3,5-benzene precursors can help reduce the formation of low-density regions and lead to better connectivity of the filling material formed under nanoconfinement; thereby yielding improved elastic and fracture properties.