Low-Temperature Process of Ferroelectric (Y0.95,Bi0.05)MnO3 Thin Films and Their Structural and Electrical Properties

• Published in: Integrated ferroelectrics Vol. 52; no. 1; pp. 163 - 170
• Main Authors: Choi, Taekjib, Kim, Si Won, Yoon, Kyung Sun, Kim, Young Sung, Lee, Jaichan
• Format: Journal Article
• Language: English
• Published: 2003
• ISSN: 1058-4587
• DOI: 10.1080/743845167

[(Y0.95,Bi0.05)MnO3] (YBM) films have been grown on Y2O3 buffered Si (001) by pulsed-laser deposition (PLD). We have compared the structural and dielectric properties of YBM films with those of typical YMnO3 films from the viewpoint of lowering the process temperature. The highly c-axis oriented YBM film have been obtained on Y2O3/Si (001) at 700DGC, which is a significantly reduced growth temperature from that of typical YMnO3 films (850DGC). The Bi modification was effective for the low temperature processing of YBM films. These highly c-axis oriented YBM films was obtained only at high ambient oxygen pressures, for example above 100 mTorr, contrary to YMnO3 films which requires low ambient oxygen pressure for the growth of c-axis preferred orientation. The dielectric constant and dissipation factor was 29 and 0.017 at 1 MHz, respectively. The memory window due to ferroelectric polarization switching was found in a capacitance-voltage (C-V) characteristic. The YBM/Y2O3/Si structure with above characteristics of YBM films exhibited the C-V memory window of 1.2 V at a sweep voltage of 5 V. The flat-band voltage shifted symmetrically with increasing the sweep voltage up to 8 V due to little charge injection from Si. As a result, the memory window increased progressively with increasing the sweep voltage and amounted to 2 V at a sweep voltage of 8 V. The leakage current density was below 5 x 10-7 A/cm2 at a bias voltage of 8 V.