Characterization of boron-doped silicon epitaxial layers by x-ray diffraction

Abstract
Heavily boron-doped (Na≳1×1019 cm−3)Si epilayers grown on (100)Si by molecular beam epitaxy are investigated using double-crystal x-ray diffractometry. The variation of the Si lattice constant as a function of boron concentration is obtained from a combination of (400) rocking curve analysis and secondary-ion mass spectrometry measurements on uniformly doped epilayers. This result is then used to determine the concentration profile in nonuniformly doped structures via dynamical simulations of experimental x-ray rocking curves. The structures investigated include a pipi doping superlattice and the results are found to be in excellent agreement with secondary-ion mass spectrometry depth profiles.