Non-contacting methods for strain and displacement measurement are now well established, although not widely used in material science. Some applications like the determination of coefficients of thermal expansion, especially of thin multilayered structures, are particularly demanding and definitely require non-contacting methods. The paper shows that laser speckle pattern shift techniques can be successfully utilized for that kind of strain and displacement measurements. We elaborate a theory of laser speckle displacement estimation and show that these optical systems are sufficiently rigid and sensitive to determine the values of thermal expansion coefficients for small to medium-sized Si-based semiconductor devices like insulated gate bipolar power transistors.
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