Self-assembly of defect-free nanostripe arrays on B-doped Si(001)

We have developed a method to grow large, self-assembled, defect-free arrays of vacancy or adatom stripes on atomically flat, boron-doped Si(001)-(2×1). The subnanometer-high stripes form between ∼870 and 990°C, with a spacing that depends on temperature. Si deposition is used to prevent sublimation-induced defect formation and to allow time for ordering via surface diffusion. Ordering mechanisms, observed in real time by low-energy electron microscopy, include island nucleation and growth, longitudinal splitting, and coarsening. At formation temperatures, the arrays are only stable when the area fractions of vacancy (θ_v) or adatom stripes (θ_a) are ∼1/2, consistent with stress domain theory predictions. At room temperature, arrays are preserved indefinitely and are a potential template for nanowire growth.