X‐ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), electron energy loss spectroscopy (EELS), and reflection high‐energy electron diffraction (RHEED) have been used to show that 30 min exposures of a degreased and deionized‐water‐rinsed Ge(001) wafer to ultraviolet (UV)–ozone in laboratory air is sufficient to remove C contamination and form a nonpermeable passive amorphous GeO2 layer with a thickness of ≂1.8 nm. Subsequent annealing in ultrahigh vacuum (UHV) at ≥390 °C for ≥30 min resulted in desorption of the oxide layer and the exposure of a clean well‐ordered Ge(001)2×1 surface. No impurities, including C and O, were detected by either XPS or AES. EELS spectra from the clean surface showed well‐defined peaks corresponding to transitions involving dangling bonds, surface states, and surface plasmons. Shorter UV–ozone exposures (i.e., <30 min) often resulted in residual C contamination while incomplete oxide removal was obtained at lower oxide desorption temperatures. Ge overlayer...