Patents Assigned to Sentech Instruments GmbH
  • Patent number: 6897955
    Abstract: This invention concerns an ellipsometer for the examination of a sample whereby the ellipsometer has a broadband light source on the emitter side and a detector on the receiver side for a receiver light beam reflected from the sample. A refractive optic for the generation of a measuring spot on the sample and an aperture arranged on the emitter side for the definition of a measuring spot on the sample. The spectroscopic ellipsometer of the present invention makes it possible to easily produce a precisely defined measuring spot on the sample.
    Type: Grant
    Filed: May 10, 2001
    Date of Patent: May 24, 2005
    Assignee: Sentech Instruments GmbH
    Inventors: Uwe Wielsch, Michael Arena, Uwe Richter, Georg Dittmar, Albrecht Kruger, Helmut Witek
  • Patent number: 5526117
    Abstract: Characteristic values of transparent layers in the nanometer range, such a layer thickness and refractive index, can be determined with a spectro-ellipsometer. The task is to determine these values even with a less elaborate ellipsometer which only operates at one or a few wavelengths. In accordance with the invention, first at least one pair of the ellipsometric angles psi and delta are measured with at least one angle of incidence of the light beams on the sample for at least one ellipsometer wavelength, from which at least one characteristic value is determined for one ellipsometer period. Furthermore, the wavelength-dependent reflection of the probe in the wavelength range of interest is photometrically measured and from this the spectral dependency of the characteristic value is determined with the ellipsometrically measured characteristic value.
    Type: Grant
    Filed: January 14, 1994
    Date of Patent: June 11, 1996
    Assignee: Sentech Instruments GmbH
    Inventors: Uwe Wielsch, Uwe Richter, Helmut Witek, Albrecht Kruger
  • Patent number: 5517128
    Abstract: In the atomic force microscopy method, the scanning system modified to provide high-frequency control is set into oscillation by electrical pulses having an amplitude that is adjustable and variable within a wide range. The pulses are so short that contact between the scanning tip and the sample is avoided. The pulse amplitude and/or form are varied in order to generate space charge zones in the semiconductor structures that are shaped differently within wide limits.
    Type: Grant
    Filed: April 29, 1994
    Date of Patent: May 14, 1996
    Assignee: Sentech Instruments GmbH
    Inventor: Uwe Henninger