No abstract

A sensitive computational method allowed the determination of normalΔnormalHf°298false(SiHCl3,normalgfalse)=−116.9± 0.7 kcal/mol based on various previously reported experimental investigations. For the first time the gaseous compounds SiCl3 and Si2Cl6 were included in a thermodynamic evaluation of the Si‐H‐Cl system. Diagrams relating normalCl/Hfalse(0.01–10false)normalto Si/normalCl over the temperature range of 400°–1700°K indicate the equilibrium state of the system with respect to the corresponding increase or decrease of silicon in the gaseous phase.

Die Partialdrücke gasförmiger Spezies, die sich im Gleichgewicht mit festem Si im System Si‐H‐Cl befinden, werden als Funktion der Temperatur bei verschiedenen Cl/H‐Verhältnissen und Gesamtdrücken behandelt.

Beim Eindampfen des rotvioletten Eluats im Vakuum wurden 15 mg einer dunkelvioletten Substanz erhalten. deren Kohlenstoff-Gehalt bei 89,7% und deren Schmp. bei 222° lag. W ir danken der Deutschen Forschungsgemeinschaft und dem Fonds der Chemischen Industrie für die finan zielle Unterstützung der vorliegenden Arbeit.

The electronic properties of chalcogens as dopants in silicon are discussed with emphasis on tellurium. Tellurium gives rise to two dominant donor levels which have been studied by junction space-charge techniques, infrared absorption, and ESR. Both donor levels exhibit excited states (Rydberg series and multivalley split-off states) which are in agreement with those expected for singly and doubly charged centers, respectively. These results suggest that tellurium causes a double donor level in silicon. One of the donor states has been identified by ESR as Te+. Hyperfine interactions with the I =nuclei Te and ' Te as well as with Si in the surrounding lattice have been observed. The ESR line shape due to the interaction with Si suggests that the tellurium donor levels occupy substitutional sites. Photo-ESR clearly shows that both the ESR signal and the data obtained from junction space-charge techniques and infrared absorption m, easurements originate from the same center. From the excited states, temperature-independent ground-state binding energies of 198.8 and 410.8 meV, respectively, have been deduced.