Applications of electron channeling pattern for the determination of wafer offcut and misorientation angles

Abstract

The epitaxial growth of semiconductor multilayers often starts from monocrystalline wafers that have an offcut angle. This offcut angle is critical for tailoring the properties of epitaxial materials, making its precise control essential. This study demonstrates a novel approach to determine the wafer offcut angle based on electron channeling patterns (ECP) obtained by scanning electron microscopy. The technique involves calculating the angular distance between the zone axis and the surface normal by analyzing a series of ECP images acquired at various rotations/tilts. The method successfully applies to Si(001) substrates with different offcut angles, measured within similar to 1 h with an angular accuracy of similar to 0.05 degrees. Additionally, the misorientation between the overlaying semiconductor crystalline films and the substrate is estimated with a precision down to similar to 0.03 degrees within similar to 30 min. This performance can meet the accuracy requirements for a wide range of industrial and research applications.