Xenon difluoride

fluor1

fluor2

fluor3

Xe decarboxylation

Xe silanes

Xenon difluoride (XeF2) is a powerful fluorinating agent with the chemical formula XeF2. It is one of the most stable xenon compounds. Xenon difluoride is a colorless, crystalline solid under standard conditions and is odorless. It is used primarily in the semiconductor industry for etching silicon microprocessors. It is also used in the synthesis of fluorine-containing compounds.

Properties

Xenon difluoride is a dense, white crystalline solid. It is highly volatile and sublimes at a temperature of about 25°C at atmospheric pressure. It is soluble in solvents such as sulfur hexafluoride, nitrogen trifluoride, and hydrogen fluoride. XeF2 is a linear molecule, with xenon having sp3d hybridization. It is a strong electrophile and a powerful fluorinating agent.

Synthesis

Xenon difluoride is synthesized by the direct combination of xenon and fluorine gases under controlled conditions. The reaction is highly exothermic:

\[ \text{Xe} + \text{F}_2 \rightarrow \text{XeF}_2 \]

This reaction typically takes place in a nickel vessel at about 400°C. The product, xenon difluoride, is then purified through sublimation.

Applications

Xenon difluoride is primarily used in the semiconductor industry. It is an effective etchant for silicon, particularly in the production of microelectromechanical systems (MEMS). Its ability to selectively etch silicon over silicon dioxide makes it valuable in the fabrication of integrated circuits.

In addition to its use in the semiconductor industry, xenon difluoride is also used in the synthesis of fluorine-containing organic compounds. It acts as a source of fluorine in various chemical reactions, facilitating the introduction of fluorine atoms into organic molecules.

Safety

Xenon difluoride is a powerful oxidizer and reacts violently with organic materials, which can lead to fires or explosions. It also poses a significant inhalation hazard and can cause severe respiratory distress if inhaled. Proper safety precautions, including the use of appropriate personal protective equipment (PPE) and ventilation, are essential when handling xenon difluoride.

See also

• Xenon hexafluoride
• Xenon tetroxide
• Fluorine chemistry
• Semiconductor device fabrication