Extra steps have been found with atomic-force microscopy generated on rather flat silicon ͑100͒ surfaces annealed at 1200°C in hydrogen, through a comparison with the surface annealed in argon, which exhibits a typical ͑S a ϩS b ͒ step structure. It is suggested that the extra steps are spontaneously generated due to the relaxation of the strain energy associated with the atomic dimers on the reconstructed surface.
A vicinal silicon (111) surface exhibits well defined single steps after being annealed at 1200 °C in hydrogen, which is in sharp contrast with step bunches featuring the surface annealed in argon. As a temporary explanation for its ability to unzip the step bunches, we suggest that hydrogen destroys the faulted triangles of a [112̄] step, eliminates this kind of step, and eventually leaves the single [1̄1̄2] steps alone behind on the surface.
The outdiffusion of boron, antimony, and phosphorus from the bare silicon wafer at 1200 °C, especially its dependence upon the annealing atmosphere, has been studied with spreading resistance and secondary ion mass spectroscopy (SIMS). It is found that the boron outdiffusion proceeds when the crystal is annealed in hydrogen, but is completely suppressed in argon even if the doping concentration is as high as 3×1018 cm−3 and the annealing time is as long as 2 h. The dramatic dependence upon the atmosphere has not been observed for the other impurities and is temporarily related with the desorption process of boron atoms from the surface.
Two new electron paramagnetic resonance (EPR) spectra, labeled KU2 and KU3, emerge as a result of annealing of γ-ray irradiated silicon crystals in the temperature range 360–560 °C. The EPR intensities of KU2 and KU3 increase in the upper range of the annealing temperature where the EPR peaks of the vacancy-oxygen complex (A-center) diminish. The angular dependence study shows that the EPR spectra of KU2 and KU3 resemble that of SL1, the excited triplet (spin S = 1) state of A-centers, but with slightly different g and D-tensors representing lowering in symmetries. Microscopic lattice distortions caused by capturing of extra interstitial oxygen atoms by the A-centers are proposed to be the source of lowering of the symmetries associated with KU2 and KU3.
Electron spin resonance (ESR) spectra of surface and interface recombination centers recently observed on (001) silicon wafers, labeled P m and KU1, were studied using spin dependent microwave photoconductivity. Both ESR spectra, having the orthorhombic symmetry and spins S ¼ 1/2 and S ¼ 1 for P m and KU1, respectively, were observed in the commercially available surface oxidized (001)-Si wafers. Systematic studies on annealing and oxidation conditions for the P m and KU1 formation conclude that both ESR spectra arise from the same center that contains the interaction between the two nearest Si dangling bonds on the (001) Si surface.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.