Micro Raman Spectroscopy

Raman spectroscopy is an inelastic light scattering technique that measures the vibrational spectra of molecules and solids. The spectra provide detailed information about the character of the chemical bonds. Raman spectroscopy is typically used to identify contaminates or to analyze solids such as polysilicon, metal silicides and strained silicon. This technique is useful because it is non-destructive and relatively quick. The lateral resolution of the incident beam is on the order of 1 micron. However, the total collection volume depends on the light scattering properties of the material being analyzed. For example, the penetration depth in polysilicon is approximately 2000Å. Our Raman spectrometer is coupled to a precision Leica INM200 microscope review station. This allows us to download defect maps from inspection tools and drive to within microns of the defect on 200 mm wafers.