Clustering of oxygen atoms around carbon in silicon

Abstract

Transmission electron microscope studies of carbon-doped Czochralski silicon, when combined with previous infrared data on the same specimens, reveal a double peak in the carbon-sited oxygen-cluster size distribution after 64 h at 750 °C. The first peak, which represents most of the carbon and oxygen in the specimen, is comprised of clusters with an average of two oxygens per carbon atom. These clusters can survive 64 h at 1000 °C although they are not created by such an anneal, suggesting that carbon atoms have difficulty trapping a first oxygen atom at 1000 °C. The second peak in the distribution near 104 oxygen atoms in size is populated with regular {111}-octahedral precipitates having large dilatational strain fields. The two peaks in the size distribution, and their dependences on heat treatment, indicate roles for both seeding (creation of metastable clusters below critical size) and nucleation (achievement of energetic stability) in the formation of carbon-sited precipitates. The observations confirm a trend toward octahedral precipitate morphologies in carbon-doped specimens. However, the trend may result not from site differences but from effects of carbon or point defects on strain energy during precritical cluster growth. Finally, differences between secondary defects associated with precipitation in low- and high-carbon specimens suggest that substitutional carbon atoms at 1000 °C act as sites for silicon self-interstitial condensation near precipitates.

Structural and electrical properties of oxygen complexes in Cz and FZ silicon crystals implanted with carbon ions

“…The TDs concentration is determined by the carbon content in the C s state, the total oxygen content inside the Si crystal, and annealing parameters. The TD ionization energy E i is ≥12 meV, which is fully consistent with the model of thermal donors-II (new thermal donors) for Si crystals proposed in[ 12 ]. In this model, the E i dependence on the oxygen cluster size was established.…”

“…The carbon atom serves as a nucleation site for the growing SiO x cluster. Each cluster includes one carbon atom and a few oxygen atoms[ 6 , 12 – 14 ]. The TDs concentration is determined by the carbon content in the C s state, the total oxygen content inside the Si crystal, and annealing parameters.…”

Effect of the Silicon Nitride Coating of Quartz Crucible on Impurity Distribution in Ingot‐Cast Multicrystalline Silicon

“…Thus, the production of mc‐Si solar cells currently occupies approximately two thirds of the photovoltaic market . However, defects and impurity elements, such as C, O, Fe, and Ca, play a crucial role in the degradation of mc‐Si solar cell performance.…”

Controlled doping by self-assembled dendrimer-like macromolecules

“…To exclude any potential electrical interference, the best candidate for the carrier molecule is the one that is large (at least a few nanometer in diameter to be comparable to the resolution of the most advanced lithography) and mostly importantly, only has C, O and H in addition to the dopant element such as P or B since C, O and H do not electrically dope silicon 12 13 . Here, we demonstrate a novel monolayer doping approach by using the super-branched poly-glycerol molecules that are synthesized to carry only one phosphorus atom in the core ( Fig.…”