Spatially resolved thickness analysis of microscale structures using micro-Raman spectroscopy

A novel method, by using micro-Raman spectroscopy, is developed to measure the thickness of microelectromechanical system structures with high spatial resolution. When a microscale structure is heated by a laser, the temperature rise of the structure depends on the structure thickness and material properties. Therefore, the structure thickness can be measured using Raman shift, which is a function of temperature. Micro-Raman spectrometer is capable of measuring the thickness distribution of microscale structures with micron spatial resolution. This technique is evaluated by characterizing the thickness distribution of a single-crystal silicon (c-Si) membrane. The measured thickness distributions are verified by scanning electron microscope measurement. (c) 2006 American Institute of Physics.