Abstract: Methods and apparatus for chemical mechanical planarization (CMP) of a polymer or epoxy-based layer. In some embodiments, the method may comprise obtaining an endpoint for polymer or epoxy-based material for use in a CMP process, the CMP process configured to polish polymer or epoxy-based material, monitoring the polymer or epoxy-based layer with an endpoint detection apparatus configured to monitor polymer or epoxy-based material, polishing the polymer or epoxy-based layer with the CMP process, detecting when the polymer or epoxy-based layer has reached the endpoint for the CMP process, and halting the CMP process when the endpoint is detected. The endpoint detection apparatus may further comprise an optical detection apparatus configured to operate at a wavelength of approximately 200 nm to approximately 1700 nm to reduce step height of the polymer or epoxy-based layer.