p-type AMMONO-GaN substrates revealed
AMMONO SA has announced a new product to the portfolio - the p-type truly bulk AMMONO-GaN substrate.
Typically, dedicated donor doping can increase GaN conductivity, providing electrons as majority charge carriers (n-type). Successful and efficient p-type doping of GaN was always a difficult technological task, because of high activation energy of typical acceptors. Up till today only thin layers of p-type GaN could be obtained by epitaxial methods or ion implantation.
In the ammonothermal process the incorporation of acceptor during the growth results in a larger hole concentration and p-type conductivity, without generation of structural defects. The dislocation density in p-type AMMONO-GaN remains the same as the dislocation density of n-type AMMONO-GaN substrates, being below 5x104 cm-2. Carrier (free hole) concentration in this material is at the level of 1016 cm-3, while electrical resistivity is 10-100 Ω*cm.
These new p-type GaN substrates should enable construction of novel devices. In the area, where many solutions are already patented, the introduction of such a new substrate offers new potential for device architectures. It is expected that laser diodes, LEDs, high power transistors and high frequency transistors may gain many benefits by using this new material.
