Electrical AC behaviour of MPCVD diamond Schottky diodes

• Type: Article in International Scientific Journal
• Date: 2001

Authors

Pereira, L (Author) Other; Alírio Rodrigues (Author) FEUP; Gomes, H (Author) Other; Pereira, E (Author) Other

Journal

Title: Diamond and Related Materials

Vol. 10

Pages: 615-619

ISSN: 0925-9635

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 11 Citations

Scopus - 10 Citations

Other information

Authenticus ID: P-000-W78

DOI: 10.1016/s0925-9635(00)00442-8

Abstract (EN): The present work reports some experimental results on the electrical AC behaviour of metal-undoped diamond Schottky diodes fabricated with a free-standing MPCVD diamond film (5 mum thick). The metals are gold for the ohmic contact and aluminium for the rectifier. The capacitance and loss tangent vs, frequency shows that capacitance presents a relaxation maximum at frequencies near 10 kHz at room temperature. Although the simple model (small equivalent circuit) can justify the values for the relaxation, it cannot justify the departure from the Debye model, also verified in the Cole-Cole plot. Taking into account the existence of traps in the depletion region, a best fit to the experimental results was obtained. The difference between the Fermi level and the band edge of 0.2-0.3 eV is in agreement with the activation energy found from the loss tangent analysis. The capacitance with applied voltage (Mott-Schottky plots) gives a defect density of 10(16) cm(-3) with contact potentials near 0.5 V and the profile of defect density obtained shows a major density (approx. 10(17) cm(-3)) in a layer with a thickness less than 50 nm from the junction, decreasing by one order of magnitude with increasing distance. Finally a structural model is proposed to explain the AC behaviour found.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5