Direct Patterning of Low-K Material for Damascene Process

Abstract

AbstractThere are several activities in the development of low dielectric constant materials, including fluorlnation of SiO2, low-k organic polymers, and porous materials. No one material satisfies all the requirements for multilevel interconnections, which include low dielectric constant, high mechanical strength, good dimensional stability, good high temperature stability, easy processing, and low H2O absorption and outgassing. In this research, a new material system has been studied. This process-controlled low-k material can have dielectric constant as low as 2.0 with good thermal stability. It can provide low viscosity for reflow processing to achieve excellent planarization and gap filling. Low moisture uptake and high mechanical strength can be achieved. Most interesting is, it can be made to be photosensitive at deep-UV range, which provides the possibility of eliminating many chemicals and complicated processes in photolithography. Process cost can be expected to drop significantly. Damascene and dual damascene processes were proposed using this new low-k material, which can be much simpler compared to the traditional process.