Large reduction of threading dislocations in diamond by hot-filament chemical vapor deposition accompanying W incorporations

Dislocations in semiconductor crystals are desirably minimized as much as possible, since their presence typically deteriorates device performance. While diamond electronics have demonstrated superior device properties, they have not fulfilled their material limit yet. To further improve device performance, a low dislocation density and a high-quality epitaxial layer are required. In this study, diamond films are homoepitaxially grown by hot-filament chemical vapor deposition accompanying W incorporations from heated metal-wires. The films exhibited better crystalline quality than seed substrates: a large reduction of threading dislocation from 2 × 106 to 3 × 104 cm−2 was demonstrated. The dislocation propagation was partially annihilated by W impurities. The electrical properties of Schottky barrier diodes after dislocation reduction were highly uniform, improved rectifying actions.