Method of accurately measuring compositions of thin film shape memory alloys
AssigneeTiNi Alloy Company
InventorsA. David Johnson, Valery Martynov
Life of this patent
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Abstract
A method of measuring with high accuracy the composition of shape memory alloy elements that are sputter deposited in thin film form. An element of known composition is polished with a flat surface. An element of unknown composition is sputter deposited onto the surface. Miniature openings are made by photography in the unknown layer, exposing an area of the known substrate. With adjacent areas of the two samples then only microns apart, accurate measurements of the compositions are made by comparing the X-ray spectra resulting from an electron beam scanning across the two areas.
Claims4
A method of accurately measuring the composition of alloys comprised of elements of known and unknown compossitions that are sputter deposited in thin film form, comprising the steps of providing a first layer of the element of known composition, the first layer having a surface, adhering a second layer of the element of unknown composition on the surface, forming an opening in one of the layers by a step selected from the group consisting of forming the opening through the second layer sufficient to expose an area on the first layer of the known composition element and forming an other opening through the first layer sufficient to expose an area on the second layer of the unknown composition, scanning an electron beam between the exposed area and the layer through which the opening is formed, comparing X-ray spectra from the element of the composition in the exposed area with X-ray spectra from the element of the composition in the layer through which the opening is formed, and computing the compositions of the elements as a function of the X-ray spectra comparison.
A method as in claim and further comprising the steps of iteratively repeating the step of computing the compositions, and statistically determining responsive to the iteratively repeating step the composition measurement to an accuracy within 0.1%.
Dependencies are inferred from the claim text.