Advanced Micro Devices Corporation

Donald A Tiffin

Tim Z Hossain

Ying Li

Michael C Barrett

Chih-Kang Shih

Joel R Stanford

Michael J Dennis

An apparatus and method are present which use X-ray fluorescence techniques to determine the roughness of a target surface. The apparatus includes an X-ray source and an X-ray detector. The X-ray source produces primary X-ray photons formed into a primary X-ray beam, and the primary X-ray beam is directed to and incident upon the target surface. The X-ray detector is positioned to receive primary X-ray photons scattered by the target surface. A fraction of the primary X-ray photons scattered by the target surface is directly proportional to the roughness of the target surface. The roughness of the target surface is determined from the number of primary X-ray photons scattered by the target surface and received by the X-ray detector within a predetermined exposure time. The X-ray detector produces an output signal proportional to the energy levels of received X-ray photons. An energy range of interest is divided into segments. A computer system receives the X-ray detector output signals and increments corresponding counts associated with segments of the energy range of interest. Following exposure, the computer system produces a graph of the counts associated with each segment. The computer system also reviews the counts associated with a peak in the graph corresponding to the energy levels of the scattered primary X-ray photons, determines selected characteristics of the peak (e.g., a maximum count associated with the peak, the area under the peak, etc.), and uses calibration data to compute a surface roughness value.

Apparatus and method for measuring the roughness of a target material

An apparatus and method are presented for determining the identity and quantity of elements embedded within a thin film. A radioisotopic source produces a beam of primary x-rays which impinge at near-grazing angles upon a sample consisting of a thin film and an underlying semiconductor substrate. The beam of primary x-rays cause the emission of characteristic secondary x-ray photons from the thin film of the sample. These secondary x-ray photons are detected by a detector positioned above the sample. The detected X-ray photons are counted and their energies are determined, allowing for the determination of the identity and quantity of elements within the thin film.

Apparatus and method for characterizing particles embedded within a thin

An apparatus and method are presented for determining the elemental compositions and relative locations of particles on a surface of a semiconductor wafer. An exposed region of the surface of the semiconductor wafer is subjected to a beam of primary X-ray photons, and secondary X-ray photons emitted by atoms of elements on and just under the surface of the semiconductor wafer are detected by an X-ray detector array which includes multiple X-ray detectors. Each X-ray detector produces an output signal which is proportional to energy levels of incident X-ray photons. The X-ray detectors are laterally displaced from one another, and arranged to allow two-dimensional resolution of detected secondary X-ray photons emitted by atoms of elements on the surface of the semiconductor wafer. The X-ray detector array is preferably an electronic area image sensor including a two-dimensional array of photosensor elements formed upon a monolithic semiconductor substrate. With adequate resolution, the X-ray detector array may also provide information as to the relative sizes of particles on the surface of the semiconductor wafer. By virtue of an employed total reflection X-ray fluorescence (TXRF) technique, substantially all of the detected X-ray photons are secondary X-ray photons emitted by atoms of elements located on and just under the exposed surface of the semiconductor wafer.

Apparatus and method for determining the elemental compositions and

A method is provided for measuring at resolutions which are in some instances less than 20 nanometers the concentration densities within one or more diffusion regions within a semiconductor substrate. The diffusion regions are prepared for measurement by cleaving a cross-sectional surface and polishing that surface to a substantially flat, exposed profile. The profile is purposefully pre-etched to remove oxide abutting the implant area and thereafter dopant-selective etched in accordance with concentration densities within the substrate. Pre-etching of oxide and concentration density etching of doped silicon provides an exposed topological contour measurable by atomic force microscopy (AFM). AFM can detect the entire cross-sectional surface including conductors and dielectrics. The topological height of impurity region profiles of a calibration wafer are correlated to impurity concentrations to form a calibration curve. The calibration curve, in conjunction with topological contour of a target region profile, allows direct and quick measurement of concentration densities along the target region profile at each AFM scan location. The initial scan position is purposefully defined by an oxide pre-etch step to present an easily discernible AFM-read gradient which signals an initial AFM read position.

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Austin, TX, United States of America

Donald A Tiffin