Date: 18/12/2008

Gallium Nitride (GaN) power diode with a new junction structure

Panasonic announced the development of a Gallium Nitride (GaN) -based diode with a new junction structure called "Natural Super Junction". The new GaN diode with low operating loss is applicable to a variety of consumer and industrial power switching systems.

The new junction structure consists of multi-layered GaN-based semiconductor thin films with different compositions of which each interface produces fixed positive and negative charges by the material's unique polarization. The layered structure acts as an insulator at the reverse bias owing to the complete balancing of the fixed charges so that the breakdown voltage can be increased just by extension of the distance between the two electrodes. The increase of the number of the multi-layer resulting in the increase of the current channels effectively reduces the on-state resistances as well.
The proposed device structure is similar to super junction of Silicon devices in which p-type and n-type layers are alternately stacked. The new junction structure does not require any precise control of the doping concentration in the layers as is necessary for the Silicon super junction. The high breakdown voltages can be achieved taking advantage of naturally formed fixed charges and thus it can be called natural super junction.

The new GaN-based diode exhibits high breakdown voltage of 9400 V with low on-state resistance of 52 mOcm2, which reaches the predicted limitation by GaN-based semiconductors for the first time.

For more information visit the company's website at www.panasonic.net