LPE growth of AlN from Cu-Al-Ti solution under nitrogen atmosphere

Synthesis of single crystalline AlN has long been the subjects of intensive studies since it has exceptional properties suitable for the substrate materials for optoelectronic and electronic devices. The solution growth technique has some advantages over the sublimation growth technique. Its growth temperature is generally much lower than that of the sublimation growth. The obtained crystal is believed to show superior crystallinity since it is grown under nearly equilibrium condition. In the present study we have developed a new solution growth technique using Cu and Ti as solvents under atmospheric pressure of nitrogen. By using this solution, we have grown AlN single crystalline layer on 6H-SiC substrate at relatively low growth temperatures such as 1600-1800°C. The thickness of the grown layer was larger than 30 μm. TEM observation revealed the fairly low dislocation density such as 10 ⁵/cm ² in the obtained AlN layers.