Patent ID: 8570513
Filing Date: 2013-10-29
Classification: G01N

Abstract:
1. A method of improving results achieved by investigating a sample with a textured surface with electromagnetic radiation, said texturing being characterized by a non-random effectively “regular” textured surface and/or a surface characterized by an irregular array of faceted structures; said method comprising: a) providing a spectroscopic ellipsometer which comprises: said spectroscopic ellipsometer further comprising at least one selection from the group consisting of: b) placing a sample with a specularly reflecting surface on said stage so that said specularly reflecting surface faces away from said stage; c) while causing said spectroscopic source of a beam of electromagnetic radiation to direct a spectroscopic beam of electromagnetic radiation to pass through said a variable attenuator and polarizer, toward said sample with a specularly reflecting surface, in coordination, adjusting the angle-of-incidence of said spectroscopic beam of electromagnetic radiation with respect to said sample, and the orientation of said sample by adjustment of said stage rotation means adjusting the orientation of said stage and stage rotation means, as a unit, with respect to said stage frame plane, and optionally adjusting said stage rotation to orient the surface of said sample a plane parallel to the surface of said stage, so that the electromagnetic radiation reflected from said sample passes through said analyzer and enters said detector; d) adjusting said variable attenuator so that the intensity of the reflected electromagnetic radiation entering said detector does not saturate said detector; e) removing said sample with a specular surface from said stage and placing a sample with a textured surface thereupon in its place; f) beginning with the setting variable attenuator arrived at in step d, in coordination adjusting the variable attenuator, and the orientation of said textured sample surface by adjustment of said stage rotation means, and tilting said stage and stage rotation means as a unit, with respect to said stage frame plane so that electromagnetic radiation reflected from said sample with a textured surface passes through said analyzer and enters said detector is of a quality to allow analysis thereof, where quality is determined is identified by data magnitude sensitivity to wavelength change or the nature of the electromagnetic beam is enhanced as evidenced by the enabling of determination of at least one selection from the group of ellipsometric PSI and ellipsomtric DELTA therefrom; g) with the sample having a textured surface oriented as in step f, obtaining ellipsometric data over a spectroscopic range of wavelengths; and h) analyzing said ellipsometric data to evaluate optical and physical properties of said textured sample.