Development of Highly-Sensitive Transient Photocapacitance Mesurement System for Deep Defects in Boron-Doped Diamond (100) Films

We have developed a highly-sensitive transient photocapacitance measurement system for deep defects in wide bandgap materials, and applied it to characterize the boron-doped diamond films grown on a high-pressure/high-temperature-synthesized Ib diamond substrate using high-power-density microwave-plasma chemical vapor deposition method. The developed transient photocapacitance measurement system has both a low detection limit of less than 0.5 fF for changes in the photocapacitance and a low measurement temperature drift of less than 0.03 K in 12 h. By using the transient photocapacitance measurement system, we have successfully found an acceptor-type defect around 1.2 eV above the valence band maximum for the B-doped diamond film.