Arsenic Precipitation in Heavily Arsenic‐Doped Czochralski Silicon

Abstract

Heavily arsenic‐doped Czochralski (HAs‐CZ) silicon is an important substrate material for manufacturing power electronic devices. The arsenic impurities may be in a supersaturated status in a certain temperature range during the HAs‐CZ silicon crystal growth or the device fabrication. Then, whether and how the arsenic impurities can precipitate in HAs‐CZ silicon is an intriguing and practically significant issue that has never been addressed. Herein, it is first found that arsenic precipitation can occur in HAs‐CZ silicon when subjected to appropriately prolonged anneals at 550–950 °C. The resulting second‐phase precipitates are confirmed to be of orthorhombic SiAs phase, with the lattice parameters of a = 7.12 Å, b = 9.11 Å, and c = 9.00 Å, through systematic transmission electron microscopy characterizations. Moreover, it is discovered that the presence of vacancies/interstitial silicon atoms in HAs‐CZ silicon promotes/inhibits arsenic precipitation.

Removal of Antimony from Industrial Crude Arsenic by Vacuum Sublimation: Combination of Thermodynamics and Ab Initio Molecular Dynamics

“…Considering that As and Sb react during distillation, the Gibbs free energy can be used to determine the direction of the reaction. ∆ r G is given by Equation (2).…”

“…Arsenic is widely used in the semiconductor industry due to its unique electronic properties and ability to meet specific technological needs [1,2]. With the rapid development of the semiconductor industry, the purity requirements for arsenic have become more stringent.…”