Patent ID: 9714825
Date: 2017-07-25
CPC Classifications: G01B

Claim:
1. A device for simultaneously measuring a plurality of characteristics of a wafer, the wafer including a first surface, a second surface and an etched surface positioned between the first surface and the second surface, wherein said device is comprised of: a) a support structure to selectively position the wafer, b) a broadband source, c) a beamsplitter or circulator to separate source and received light, d) an interferometer that separates or combines measurement and reference light and having a measurement leg and a reference leg, wherein said interferometer directs the measurement light in the measurement leg to reflect from the first surface, directs measurement light through the first surface to reflect from the second surface, and directs measurement light through the first surface to reflect from the etched surface, e) a receiver to receive a spectrum of a measurement of intensity versus wavelength of light reflected from the first surface, the second surface, and the etched surface simultaneously, and f) a data processing system to analyze the received spectrum and to relate periodicities in the received spectrum to simultaneously measure shape and thickness of the wafer for each of a plurality of positions of the wafer.