Current-voltage characteristics of n lateral polarity junctions in GaN

摘要

Lateral Si:N-polar/Si:Ga-polar GaN homojunctions were fabricated using metal organic chemical vapor deposition with nitrogen as the carrier and dilution gas. Nominally undoped N-polar areas are n-type conductive, while nominally undoped Ga-polar areas are insulating with carrier densities below 1 X 10~(15) cm~(-3). This allows for the fabrication of selectively doped areas within one growth step that can be used to fabricate novel lateral device structures or enhance existing Ⅲ-N-device structures. In this letter we investigated the electrical properties of the simplest case of these junctions, namely, when both sides are n-type conductive. The results of the Ⅳ measurements show a linear characteristic both for the measurement of a N-polar/Si:Ga-polar junction and a N-polar/ Si:Ga-polar/N-polar double junction. This result indicates that, as expected, there are no energy barriers between the N-polar and the Ga-polar material and that these structures can be used to achieve laterally selective doped areas in Ga-N for electronic device applications.