Using metrology to calibrate a deposition model.

摘要

Deposition is one of the critical process steps in modern semiconductor manufacturing. It is used to deposit a layer of material on top of a patterned or unpatterned surface. Deposition usually takes place after etching and before CMP (chemical mechanical polishing), sec Figure 1. When a new material is deposited, the topography of the bottom surface is partially transferred to the top surface. The new topography will impact the geometry of the in-die pattern as well as the one of the metrology targets relevant for overlay and alignment measurements. The availability of a reliable deposition model is of crucial importance for the prediction and correction of these topography variations.