Abstract: Metrology systems and methods that measure thin film thickness and or index of refraction of semiconductor wafers with at least one deposited or grown thin film layer. The present invention measures near normal incidence and grazing angle of incidence reflection (using reflected broadband UV, visible, and near infrared electromagnetic radiation) from a small region on a sample. Embodiments of the system selectively comprise a near-normal incidence spectrometer/ellipsometer, a high angle of incidence spectrometer/ellipsometer, or a combination of the two.

Abstract: Auto-calibrating spectrometers and methods that measure transmission or reflection versus wavelength of a sample without need for calibration for long periods of time. Reflection and transmission spectrometers along with auto-calibrating methods for use therewith are disclosed. Light is focused onto a sample using a lens or similar optical element that transmits light towards the sample reflects light impinging upon it, and transmits light reflected from the sample. If one monitors the light reflected from the first lens and sample, very useful information is available related to the system response versus time. The present invention monitors the reflected light from the first lens and sample, and corrects for the system changes over time using this reflected light.