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Accurate determination of surface orientation of single‐crystal wafers using high‐resolution X‐ray rocking curve measurements
Author(s) -
Kim Chang Soo,
Bin Seok Min,
Jeon HyeonGu,
O Byungsung,
Choi Young Dae
Publication year - 2013
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889813020669
Subject(s) - goniometer , wafer , orientation (vector space) , rotation (mathematics) , optics , diffractometer , materials science , surface (topology) , azimuth , crystal (programming language) , resolution (logic) , sapphire , geometry , physics , optoelectronics , laser , mathematics , scanning electron microscope , computer science , artificial intelligence , programming language
Theoretical models of the variations of the peak positions of X‐ray rocking curves as a function of the azimuthal angle of a single‐crystal wafer have been proposed. These models completely describe the variations of the peak positions both when the surface normal of a wafer is parallel and when it is not parallel to the rotation axis of the goniometer used. Based on the models, an accurate measurement method for the surface orientation of a single‐crystal wafer with a small surface miscut of <∼3° has been proposed through rocking curve measurements using a high‐resolution X‐ray diffractometer. The method measures the misalignment of the sample surface normal with respect to the rotation axis of the goniometer as well as the surface orientation of the wafer. The surface orientation has been measured for a 6 inch (152.4 mm) single‐crystal sapphire wafer, and the misalignment of the surface normal from the rotation axis was determined. The results were compared with those from a different method. In addition, a simple and accurate method to obtain the surface orientation of a wafer is proposed by measuring only four rocking curves, two each at two sample azimuths 180° apart.