Surface photo-acoustic film measurement device and technique
AssigneeKLA-Tencor Technologies Corporation
InventorGary Janik
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Abstract
A method for determining the thickness and other properties of a metal layer comprising producing an acoustic wave at a first frequency in the metal layer with a first laser beam, measuring the angle of diffraction of a second laser beam from the acoustic wave, and calculating the wavelength of the acoustic wave and thickness of the metal layer from the angle of diffraction.
Claims40
A method for determining the thickness of a layer on a semiconductor comprising:
- producing a surface acoustic wave at a first frequency in the layer with a first laser beam;
- measuring the angle of diffraction of a second laser beam from the surface acoustic wave;
- and
- calculating the wavelength of the surface acoustic wave and thickness of the layer from the angle of diffraction.
A system for measuring a property of a material comprising:
- a first laser, the first laser creating a first beam, the first beam creating an surface acoustic wave at a first frequency in the material;
- a second laser, the second laser creating a second beam, a portion of which is diffracted by the surface acoustic wave in the material;
- and
- a position sensing detector that measures the angle of diffraction of the diffracted portion of the second beam.
The system of 16, wherein the first frequency is about 300 MHz.
A method for determining a property of substrate or layer upon a substrate comprising:
- heating a region of the substrate with a first laser beam modulated at a first constant frequency so as to launch surface acoustic waves at the first frequency within the substrate and layer upon the substrate;
- and
- measuring the angle of diffraction of a second laser beam from the surface and/or the substrate.
Dependencies are inferred from the claim text.