Boron-deuterium complexes in diamond: How inhomogeneity leads to incorrect carrier type identification

Abstract

International audienceThe electrical properties of boron doped diamond layers after deuterium diffusion have been investigated by Hall effect and capacitance voltage measurements. It is found that (i) the deuterated boron doped diamond layers are inhomogeneous after the deuterium diffusion, resulting in conducting and insulating areas; (ii) negative and positive Hall voltages are measured on the same boron doped sample after deuterium diffusion, depending on the contact geometry (negative with van der Pauw and positive with mesa etched Hall bar); and (iii) in the conducting area, the majority of the boron-deuterium complexes are not ionized after the deuterium diffusion. The detailed electrical measurements using mesa-insulating Hall bar structures revealed that the existence of inhomogeneous regions with conducting and insulating areas is the most probable source of wrong n-type conductivity in deuterated boron doped diamond layers of this work. In the light of this result, the possibility of an incorrect assignment of a shallow donor previously reported in deuterated boron doped diamond is discussed. Finally, confirmation is given that the boron deuterium complexes created after the deuterium diffusion are neutral in p-type diamond

Electrical transport properties of Si-doped hexagonal boron nitride epilayers

“…21 This can be achieved via the use of square shaped van der Pauw sample geometry with square or triangular ohmic contacts fabricated on the four corners of the sample. [21][22][23] A recent theoretical study has concluded that "if the ohmic contacts of a square-shaped sample are placed in the corners (and not in the sample interior), the measured carrier type will be correct even in the case of macroscopically inhomogeneous carrier concentrations and/or mobilities". 22 The schematic and microscope image of a fabricated hBN:Si sample and ohmic contact (Ni/Au bilayers) geometry employed for the Hall effect measurements are shown in Fig.…”

Carbon-rich hexagonal (BN)C alloys

“…This was achieved via the use of square shaped sample geometry with small ohmic contacts fabricated on the four corners of the sample surface. 9,13,[17][18][19] The microscope image of a fabricated h-(BN) 1Àx (C 2 ) x alloy (x ¼ 0.95) sample with four ohmic contacts (Ni/Au bilayers) on the corners is shown in Fig. 2(a).…”

Impurity characterization in diamond for quantum and electronic applications: advances with time-resolved cathodoluminescence

“…The resulting depletion region should decrease the effective layer thickness for hole transport in the p-type layer. The associated built-in electrical field would also modify the H + diffusion in p-type diamond [25] and might be responsible for the Hall voltage discrepancies measured in hydrogen-passivated boron-doped diamond at the macroscopic scale [26]. Finally, we discuss the limits of detection of impurities in the present approach.…”