Strain mapping with parts-per-million resolution in synthetic type-Ib diamond plates

Abstract

A general method to map strain with parts per million (ppm) resolution in single-crystal wafers and plates is demonstrated. An x-ray technique has been used to obtain separate maps of strain and tilt across synthetic diamond growth sectors. Data consisting of rocking curve maps obtained with a charge coupled device detector were analyzed. The strain results image the growth sectors and reveal a strain pileup near the sector boundaries. The diamond was yellow to the eye due to nitrogen impurities. Not only the topography of the strain map, but also the strain magnitudes, are consistent with the strain arising from nitrogen impurities. High strain resolution in the ppm range is needed to observe these effects.

High resolution X‐ray diffraction study of single crystal diamond radiators

“…All the above imperfections of the diamond crystal will cause the variation of the lattice constant and/or the change of orientation of the lattice plane. These changes can be measured by experimental methods such as the high resolution X‐ray topography and rocking curve measurements 9–14, Raman spectroscopy 15, TEM 16, polarized light microscopy 17, etc. The coherent bremsstrahlung process can also be used to check the crystal quality; however, it needs a dedicated high energy electron beam line.…”

X-ray reflectivity of chemically vapor-deposited diamond single crystals in the Laue geometry

“…The main assumption about R 0 is that the interactions between the crystal blocks are not considered, their influence is reduced to a simple description given by the angular distribution function W (∆), while variations in the local values of the lattice parameter are neglected. Far from the Bragg backscattering condition (θ < π/2) the angular variations tend to dominate the relative variations in the lattice parameter (e.g., [12,13]).…”

Diamond X-ray photodiode for white and monochromatic SR beams

“…This material can be contrasted with the typically higher impurity levels of high-pressure, high-temperature (HPHT) diamond which can be grown faster and often with higher crystal quality; in that case, ppm-level nitrogen uniformity can yield a strain-free yet electrically inferior crystal [3,4]. That is, the ultra-low impurity level necessary for production of sensors with minimal charge trapping (large charge collection distance) requires the slower CVD process.…”