| 摘要 |
Disclosed is a process for analyzing the surface characteristics of opaque materials. The method comprises in one embodiment the use of a UV reflectometer to build a calibration matrix of data from a set of control samples and correlating a desired surface characteristic such as roughness or surface area to the set of reflectances of the control samples. The UV reflectometer is then used to measure the reflectances of a test sample of unknown surface characteristics. Reflectances are taken at a variety of angles of reflection for a variety of wavelengths, preferably between about 250 nanometers to about 400 nanometers. These reflectances are then compared against the reflectances of the calibration matrix in order to correlate the closest data in the calibration matrix. By so doing, a variety of information is thereby concluded, due to the broad spectrum of wavelengths and angles of reflection used. This includes information pertaining to the roughness and surface area, as well as other surface characteristics such as grain size, grain density, grain shape, and boundary size between the grains. Surface characteristic evaluation can be conducted in-process in a manner which is non-destructive to the test sample. The method is particularly useful for determining the capacitance of highly granular polysilicon test samples used in the construction of capacitator plates in integrated circuit technology, and can be used to determine the existence of flat smooth surfaces, and the presence of prismatic and hemispherical irregularities on flat smooth surfaces.
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