Basic Condition for the Pair Diffusion Model of Group V Impurities in Silicon

When the impurity concentration is high, every vacancy is under the influence of impurity atoms and the vacancy formation energy appears to decrease due to the interaction between a vacancy and two impurity atoms. Since the vacancy formation energy is defined under the condition of no influence of impurity, the decrease is called a decrease in quasi vacancy formation energy, showing that a vacancy is under the influence of impurity atoms.

Decrease in Quasi Vacancy Formation Energy in the Study of Pair Diffusion Model of Group V Impurities in Silicon

Yoshida¹

1993

Impurity Diffusion in Silicon Based on the Pair Diffusion Model and Decrease in Quasi-Vacancy Formation Energy. Part One: Phosphorus

Yoshida¹,

Arai

1995

The binding energy, E b, between a vacancy and a P atom or an As atom in Si is large. Therefore the pair diffusion model (PDM) and the decrease in quasi-vacancy formation energy are applicable to P and As diffusions. With the decrease in quasi-vacancy formation energy, E b also decreases. Fermi level obtained from the Boltzmann statistics is used. Anomalous diffusion of P consists of two components, a tail and a plateau. The tail has been attributed to excess vacancies, the generation of which is a characteristic of PDM. The plateau has been explained by PDM and the decrease in quasi-vacancy formation energy. The reason for this is given for the first time. It is emphasized that the large value of the phosphorus effective diffusion coefficient at the plateau is not anomalous but normal.

Impurity Diffusion in Silicon Based on the Pair Diffusion Model and Decrease in Quasi-Vacancy Formation Energy. Part Two: Arsenic

Yoshida¹,

Arai²

1996

The state-selective dissociation dynamics for anionic and excited neutral fragments of gaseous SiCl 4 following Cl 2p and Si 2p core-level excitations were characterized by combining measurements of the photoninduced anionic dissociation, x-ray absorption and UV/visible dispersed fluorescence. The transitions of core electrons to high Rydberg states/doubly excited states in the vicinity of both Si 2p and Cl 2p ionization thresholds of gaseous SiCl 4 lead to a remarkably enhanced production of anionic, Si − and Cl − , fragments and excited neutral atomic, Si * , fragments. This enhancement via core-level excitation near the ionization threshold of gaseous SiCl 4 is explained in terms of the contributions from the Auger decay of doubly excited states, shake-modified resonant Auger decay, or/and post-collision interaction. These complementary results provide insight into the state-selective anionic and excited neutral fragmentation of gaseous molecules via core-level excitation.