Statistical equipment modeling for VLSI manufacturing: an application for LPCVD

An equipment characterization and modeling methodology has been developed. The methodology is based on the development of generic first-principle process models. These models are subsequently refined and fitted to specific manufacturing equipment by using a multistage D-optimal experimental design. The methodology has been successfully applied to a low-pressure chemical vapor deposition (LPCVD) furnace for undoped polysilicon deposition. A two-stage D-optimal experiment with 24 runs has yielded fitted models for the film growth rate and film residual stress. The calibrated models agree well with the experimental data and account for the observed variations.>