DIAMOND VERTICAL PN SCHOTTKY DIODES WITH PRESISION NITROGEN-DOPED n- LAYER

In this work, we carried out the experiments to optimize vertical Schottky pn diodes with a nitrogen concentration in the n- layer of <10 ppb by varying the boron concentration in the substrate and the layer thickness. Schottky pn diodes were manufactured, representing a boron-doped diamond substrate with a thickness of 250 – 300 μm and linear dimensions of 2.5 – 4 mm, obtained by the temperature gradient method at high pressure and temperature, on which a low nitrogen doped layer with a thickness of approximately 5 μm and a nitrogen concentration of ~1 – 10 ppb was deposited. The concentration of boron in the substrate varied from 2 to 100 ppm. The area of the electrical contacts was 6.25 mm2.We investigated the current-voltage and capacitance-voltage characteristics of the diodes. The volt-farad characteristics showed the independence of the capacitance of diodes on the locking voltage, which indicates a complete depletion of the drift layer of the diode. This confirms that these diodes are pn Schottky diodes. The maximum integral forward current value was limited by the substrate resistance and amounted to 0.1 A at 10 V, with a Schottky contact area of 6.25 mm2. This is significantly lower than the record characteristics of diamond Schottky diodes. In addition, a direct relationship between the concentration of boron in the grown layer and the concentration of boron in the substrate was revealed. Thus, it is concluded that in order to achieve the lowest possible concentrations of donor centers in the n- layer and to prevent their overcompensation by acceptors, it is necessary to use boron-doped substrates with a boron concentration of ~1017 cm-3. For citation: Timoshenko V.O., Prikhodko D.D., Tarelkin S.A., Kornilov N.V., Luparev N.V., Golovanov A.V. Diamond vertical pn Schottky diodes with presision nitrogen-doped n- layer. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 10. P. 73-79. DOI: 10.6060/ivkkt.20246710.11y.