Scanning microscope using an i/q-interferometer

Abstract

The present invention relates to a scanning microscope using an I/Q-interferometer. The scanning microscope includes an I/Q-interferometer which demodulates the phase change and amplitude change induced on the probe beam to provide the I- and Q-signals, an XY scanner, a scanner driver, a precision motion stage controlling the displacement of the sample along the direction parallel to the direction of the probe beam, a motion stage driver, a focusing/collimating device, and a computer. The computer transfers control commands to the scanner driver for scanning the XY scanner, receives I- and Q-signal provided from the I/Q-interferometer, processes the I- and Q-signal to obtain the corresponding phase and amplitude values at each scanning point, calculates error signal for maintaining constant phase during the scanning, and transfers commands to the motion stage driver for the precision motion stage to compensate for phase changes caused by surface morphology during the scanning. The scanning microscope performs a multilayer scanning or a constant phase scanning to extract information for the surface or inside of the sample.