Channeling-in channeling-out revisited: selected area electron channeling and electron backscatter diffraction

• Channeling-in strongly modulates EBSD quality metrics. • Selected-area ECP reveals dependence of EBSD signal to noise ratio. • Wide-area EBSD maps contain hidden channeling patterns. Scanning electron microscopy combined with electron backscatter diffraction (EBSD) and electron channeling provides rich crystallographic contrast, but the mutual influence of channeling‑in and channeling‑out is often simplified or neglected in quantitative analyses. In this work, we collect selected‑area electron channeling patterns (SA‑ECPs) acquired from a single‑crystal silicon wafer while concurrently recording an EBSD pattern at every incident beam direction, thereby directly probing how channeling‑in affects the EBSD signal. We show that common Hough‑based EBSD quality metrics (pattern quality, band contrast, and band slope), pattern‑matching cross‑correlation coefficients, and Fourier‑based signal‑to‑noise ratios all exhibit strong crystallographic modulations that follow the underlying ECP, in both raw and background‑corrected patterns. Variations can be up to ∼20% of the measured signal. Similar wide‑angle channeling features are also visible in conventionally-collect low‑magnification EBSD maps, indicating that channeling‑in effects are relevant under routine mapping conditions and not only in specialized ECP experiments. These observations highlight that channeling‑in can significantly bias quality‑based interpretation of EBSD data, with consequences for methods such as pattern blurring analysis, high‑resolution strain mapping, and emerging statistical or machine‑learning approaches that rely on subtle variations in diffraction patterns. The combined SA‑ECP and EBSD strategy presented here offers a practical framework to visualize and potentially control channeling‑in/channeling‑out coupling in the SEM, suggesting new routes to design experiments and detector configurations that either mitigate or intentionally exploit these dynamical effects.