Tunneling microscopy of steps on vicinal Ge(001) and Si(001) surfaces

Tunneling images of vicinal Si(001) and vicinal Ge(001) are presented. When these surfaces are cut with a tilt about [110], we find that a large fraction of the steps are straight double steps. A Ge(001) surface cut with a tilt about a line deviating from [110] exhibits monoatomic steps, some of which have many kinks.