Simplification of Replacement Metal Gate CMP metrology for FinFET

We have demonstrated that measurement of the gate height in the complex 3D FinFET device post Replacement Metal Gate (RMG) Chemical Mechanical Planarization (CMP) does not require direct measurement of the FinFET. A simple metal line array built on planar silicon is an excellent substitute as the gate height of this structure matches the FinFET closely. Optical Critical Dimension (OCD) measurements of this structure are less complicated and less prone to mismeasurement. This structure can also be easily measured with X-ray Fluorescence (XRF) which can be used as a primary or secondary metrology method for process control. Additional insights based on experiences with Samsung's 14nm FinFET process will be discussed.