On the formation of arrays of single-crystal silicon islands with small angular dispersion

Abstract

We investigate the possibility of the generation of arrays of single-crystal islands with small angular dispersion in order to use them as active media for solving the problems of controlling the parameters of X-ray beams. Using the example of a three-layer structure of substrate–adhesive–single-crystal wafer, we experimentally demonstrate the possibility of controlling the profile of diffractive elements by changing its temperature. It is revealed that the main reason for island misorientation is shrinkage of the adhesive material upon its solidification. Another reason for misorientation is softening the adhesive, which occurs upon plasma-chemical etching of the wafer. These effects can be eliminated by changing the temperature of attaching the wafer to the substrate surface and by using a nonsoftening adhesive. The temperature of attaching a single-crystal wafer to the substrate is calculated from the shrinkage coefficients of the adhesive and the thermal- expansion coefficients of the components of the structure.