H(2)GaN(3) and Derivatives: A Facile Method to Gallium Nitride

Area of Science:

• Materials Science
• Inorganic Chemistry
• Nanotechnology

Background:

• Gallium nitride (GaN) heterostructures are crucial for advanced electronic and optoelectronic devices.
• Existing chemical vapor deposition (CVD) methods for GaN synthesis often require high temperatures and complex precursors.
• Development of stable, efficient, and low-temperature precursors is essential for improving GaN material fabrication.

Purpose of the Study:

• To synthesize and characterize a novel molecular precursor, H(2)GaN(3), for the chemical vapor deposition (CVD) of GaN heterostructures.
• To investigate the properties, stability, and decomposition pathways of H(2)GaN(3) as a GaN source.
• To evaluate the potential of H(2)GaN(3) for low-temperature, high-rate deposition of stoichiometric GaN thin films.

Main Methods:

• Synthesis of H(2)GaN(3) and its deuterated analogue D(2)GaN(3) via reduction of Br(2)GaN(3).
• Preparation of Br(2)GaN(3) from the thermal decomposition of a crystalline adduct (SiMe(3)N(3).GaBr(3)).
• Single-crystal X-ray diffraction for structural analysis of the precursor adduct.
• Vapor pressure and distillation studies at room temperature and low pressure.
• Normal-mode analysis and ab initio theoretical calculations for vapor-phase structure determination.
• Mass spectrometry to analyze decomposition products and vapor phase composition.
• Chemical vapor deposition experiments to grow GaN thin films.

Main Results:

• H(2)GaN(3) and D(2)GaN(3) were successfully synthesized and found to be stable, volatile molecular precursors.
• The precursor adduct SiMe(3)N(3).GaBr(3) was structurally characterized, revealing a Lewis acid-base complex.
• H(2)GaN(3) exhibits significant vapor pressure at room temperature and can be distilled without decomposition.
• Theoretical calculations and mass spectrometry indicate a trimeric structure in the vapor phase.
• Decomposition of H(2)GaN(3) yields pure, stoichiometric GaN thin films via elimination of H(2) and N(2).
• CVD using H(2)GaN(3) allows for film growth at temperatures as low as 200°C with high growth rates (up to 800 Å/min).

Conclusions:

• H(2)GaN(3) is a highly effective and practical molecular precursor for the CVD of GaN heterostructures.
• The precursor's high vapor pressure and facile decomposition pathway enable low-temperature, high-rate GaN film deposition.
• This new CVD method offers significant advantages over existing techniques for producing high-quality GaN materials.