Optimization of intermetal dielectric deposition module using simulation

A major challenge arising in the interlevel dielectric deposition processes in modern multilevel very large scale integrated technology is the filling of high aspect‐ratio spaces without voids between metal lines. Here the main concerns are step coverage and material properties of dielectric films. One approach is the multistep silicon dioxide deposition using plasma enhanced chemical vapor deposition followed by atmospheric pressure CVD from ozone/TEOS. To combine the advantages of different processes and to satisfy the device reliability requirements, one needs to optimize the relative thickness of these sequentially deposited oxide layers. In this work a profile simulator, SPEEDIE, is employed to study this multistep process. For the PECVD process a free molecular‐flow model based on the combination of a single sticking‐coefficient LPCVD model and an ion‐induced‐deposition model is used. For the atmospheric pressure CVD (APCVD) process a continuum transport model considering both gas‐phase diffusion an...