Electrical characterization of phosphorus-doped n-type homoepitaxial diamond layers by Schottky barrier diodes

Temperature-dependent current-voltage (I-V), capacitance-voltage (C-V) measurements, and frequency-dependent C-V measurements have been carried out to investigate electrical properties of phosphorus (P)-doped n-type homoepitaxial diamond layers. We have fabricated lateral dot-and-plane (with ring-shaped-gap) Schottky barrier diodes. Frequency-dependent capacitance measurements revealed the existence of a deep donor level. C-V measurements deduced that the net donor concentration was 6.2 x 10(17) cm(-3) and the corresponding built-in potential was 4.0 eV, when the P concentration was 8.3 x 10(17) cm(-3). Phosphorus electrical activity was 0.75 in the P-doped diamond layer. The carrier thermal activation energy (the donor level) was evaluated to be 0.6 eV from the relation between the net donor concentration and the carrier concentration. (C) 2004 American Institute of Physics.