| 摘要 |
<p>An automatic ellipsometer is disclosed which comprises a mechanical-optical, an electrical, and a digital (computer) component. The mechanical-optical component includes a light source, various polarizing elements (one of which spins continuously), necessary apertures, and a light detector. The electrical component includes a signal from the light detector, trigger pulses from an angular shaft encoder, and an analog-digital converter, and produces a string of digitized data in a form which can be read and analyzed by digital logical circuitry. The digital (computer) component comprises logic circuitry in sufficient quantity to store and execute a relatively simple data analysis program, there being suitably associated with the digital component, one or more print-out and/or display devices. To facilitate automation of ellipsometric operation, there is provided a sample alignment system which includes a spot-defining aperture in the incident light beam, a sample holder with capability for rotation about two perpendicular axes intersecting at the intersection of the axis of the light beam source and the axis of the detector, and a four-quadrant beam deviation detector located a convenient distance from the sample along the detector axis. In the operation of the system, the sample is properly oriented about two axes of rotation, and data in the form of light intensity transmitted through a continuously spinning analyzer in the reflected beam path is sampled at convenient angular intervals to provide data which is digitally coded, and the data then is numerically Fourier analyzed to enable extrapolated properties of the sample to be displayed or typed out. The entire sequence of operations, i.e., from sample insertion to type out or display is on the order of about 5-10 seconds.</p> |
