Correlation of ellipsometric volume fraction to polysilicon grain size from transmission electron microscopy

The actual grain size of polysilicon films as obtained by TEM is correlated to an ellipsometric method using volume fraction and effective medium approximation modeling. The deposition temperature of polysilicon thin films was evaluated using volume fraction. It was determined that as the temperature decreased, and the film approaches an amorphous layer, the volume fraction increased. The volume fraction method is also shown to be useful for post implantation and anneal monitoring of polysilicon morphology. The growth of polysilicon films following anneal and also doping and anneal can be monitored very accurately with the volume fraction measurement.