Novel hysteresis effect in ultrathin epitaxial Gd₂O₃ high-k dielectric

• Main Authors: Nazarov, A.N., Gomeniuk, Y.V., Gomeniuk, Y.Y., Lysenko, V.S., Gottlob, H.D.B., Schmidt, M., Lemme, M.C., Czernohorsky, M., Ostenc, H.J.
• Format: Article
• Language: English
• Published: Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України 2008
• Series: Semiconductor Physics Quantum Electronics & Optoelectronics
• Online Access: http://dspace.nbuv.gov.ua/handle/123456789/119074

Charge trapping in ultrathin high-k Gd₂O₃ dielectric leading to appearance of hysteresis in C–V curves is studied by capacitance-voltage, conductance-frequency and current-voltage techniques at different temperatures. It was shown that the large leakage current at a negative gate voltage causes the reversible trapping of the positive charge in the dielectric layer, without electrical degradation of the dielectric and dielectricsemiconductor interface. The capture cross-sections of the hole traps are around 10⁻¹⁸ and 2 × 10⁻²⁰ cm² . The respective shift of the C–V curve correlates with a “plateau” at the capacitance corresponding to weak accumulation at the silicon interface.