Non-contact measurement of a stress in a film on a substrate
AssigneeApplejack 199 L.P.
InventorsOanh Nguyen, Wojciech Jan Walecki
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Abstract
A method for non-contact measurement of stress in a thin-film deposited on a substrate is disclosed. The method may include measuring first topography data of a substrate having a thin-film deposited thereupon. The method may also include comparing the first topography data with second topography data of the substrate that is measured prior to thin-film deposition. The method may further include obtaining a vertical displacement of the substrate based on the comparison between the first topography data and the second topography data. The method may also include detecting a stress value in the thin-film deposited on the substrate based on a fourth-order polynomial equation and the vertical displacement.
Claims11
A method of non-contact measurement of stress in a thin-film deposited on a substrate, the method comprising:
- determining first topography data of a surface of a substrate having a thin-film deposited thereupon, wherein the determining of the first topography data is based on a reflection of a beam of light emitted towards the surface;
- comparing the first topography data with second topography data of the substrate that is measured prior to the thin-film deposition;
- obtaining a vertical displacement of the substrate based on the comparison between the first topography data and the second topography data;
- determining one or more coefficients of a fourth-order polynomial equation that is used to determine a calculated shape of the substrate for different values of stress in the thin-film deposited on the substrate, wherein the one or more coefficients are determined based on the vertical displacement such that the calculated shape as determined from the fourth-order polynomial is similar to an actual shape of the substrate;
- and
- detecting a stress value in the thin-film deposited on the substrate based on the fourth-order polynomial equation with the determined one or more coefficients.
Dependencies are inferred from the claim text.