Electrical characterization of homoepitaxial diamond p-n+ junction

Electrical properties of homoepitaxial diamond p-n(+) junction of boron (B)-doped p-type layer and phosphorus-doped n-type layer on Ib (I 11) diamond single crystal have been characterized. Current-voltage characteristics show a clear rectifying property with rectification ratio of over 10(5) at +/- 10 V From capacitance-voltage characteristics, it is found that a spatial distribution of space-charge density N-i of the p-n(+) junction is not uniform and N-i at a middle region of the space-charge layer formed at zero bias voltage is higher than that of other region of the space-charge layer. This peculiar characteristic can be explained by superposition of two effects; one is the deep dopant effect due to B atoms in the p-type layer, which makes to reduce N-i at around the edge of the space-charge layer formed at zero bias voltage. The other is the compensation of B acceptors by impurity atoms diffusing during the p-n(+) interface and incorporating during the growth of p-type layer, which makes to reduce N-i at the vicinity of the p-n(+) interface. (c) 2005 Elsevier B.V. All rights reserved.