Reflection high‐energy electron diffraction observation of GaAs surface‐prepared ultrasonic running de‐ionized water treatment

GaAs (001) surface ultrasonically cleaned under running de‐ionized water (U‐RDIW) is investigated by reflection high‐energy electron diffraction (RHEED). The RHEED observations of U‐RDIW‐treated surfaces show a spotty (1×1) pattern at room temperature and a (2×1) streaky surface reconstruction pattern at 360 °C. The experimental results indicate that chemically clean and damage‐free GaAs surfaces can be produced by U‐RDIW treatment. We discuss surface structures before/after heating using a hydrogen‐ terminated model.