n-type diamond with high room temperature electrical conductivity by deuteration of boron doped diamond layers

• Published in: Diamond and related materials 2004-04, Vol.13 (4), p.700-704
• Main Authors: Saguy, C., Kalish, R., Cytermann, C., Teukam, Z., Chevallier, J., Jomard, F., Tromson-Carli, A., Butler, J.E., Baron, C., Deneuville, A.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Conductivity of specific materials; Defect-complexes; Doped diamond; Electrical properties; Electronic transport in condensed matter; Elemental semiconductors; Exact sciences and technology; Physics
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/j.diamond.2003.11.066

The conversion of the conductivity of B-doped homoepitaxially grown diamond layers from p- to n-type upon deuteration and its reconversion to p-type following annealing is extensively studied. Several B doped samples have been converted to n-type when exposed to a deuterium plasma at approximately 500 °C. The n-type features are related to D uptake of the samples. The donors, thus formed, have an ionization energy of approximately 0.34 eV below the conduction band edge and a high RT (room temperature) mobility (up to 430 cm 2/V s), as determined by Hall effect measurements as a function of temperature. In the B-doped layers that do convert to n-type upon deuteration, the D to B concentration ratio is found to be in the range of one to two. Higher D uptake (D to B ratio ≫2) must be connected to B-doped layers containing a large amount of growth defects, which trap the D. The exact nature of the donor is yet unknown. However, the reversibility of the effect and its relationship with the D concentrations suggest that deuterium is involved in the formation of some complex with B or with some other defects.