Metal-insulator-metal configuration of LaTiO3/SrTiO3 and LaAlO3/SrTiO3 hetero-structures between two dimensional electron gas formed at the interface and different area top electrodes is employed for Conductive Atomic force microscopy (CAFM) imaging, Current-Voltage (I-V), and Capacitance-Voltage (C-V) spectroscopy. Electrode area dependent I-V characteristics are observed for these oxide hetero-structures. With small area electrodes, rectifying I-V characteristics are observed, compared to, both tunneling and leakage current characteristics for large area electrodes. CAFM mapping confirmed the presence of pinholes on both surfaces. Resultant I-V characteristics have a contribution from both tunneling and leakage due to pinholes.
|Journal||Applied Physics Letters|
|State||Published - 18 Nov 2013|
Bibliographical noteFunding Information:
Authors are grateful to Professor R. C. Budhani, Director NPL for his suggestions. Dr. Toutam acknowledges CSIR for financial support. Authors would like to thank Dr. H. K. Singh and Dr. V. P. S. Awana for RT measurements and Dr. Sushil Kumar for availing C-V Spectroscopy facility. P.K. acknowledges financial assistance in the form of CSIR-SRF. A.D. acknowledges funding from IFCPAR.