Reactive ion etching damage to the electrical properties of ferroelectric thin films

Abstract

Reactive ion etching damage to Pt/Pb(Zr, Ti)O3/Pt ferroelectric capacitors was evaluated under Ar bombardment and CHClFCF3 etch plasmas. The hysteresis and degradation properties, including fatigue and leakage current, were examined systematically to study the mechanism of damage. The damage was measured quantitatively by comparing the relative voltage shift with respect to the initial hysteresis loops. The damage effects were found to be dependent on etching time and mainly due to the physical effect of ion bombardment. The electrical properties of the etched Pt/Pb(Zr, Ti)O3/Pt capacitors were substantially recovered by annealing at 400 °C for 30 min.

Characterization and elimination of dry etching damaged layer in Pt/Pb(Zr0.53Ti0.47)O3/Pt ferroelectric capacitor

“…Up to now, it is not easy to find out etching process without the etching damage during dry etching process. [2][3][4][5][6] Recently, Torii et al attempted the rf oxygen plasma treatment to reduce the etching damage. However, the etching damage was not completely removed by rf oxygen plasma treatment.…”

Nanopatterned ferroelectrics for ultrahigh density rad-hard nonvolatile memories.

“…Presently, integrated ferroelectric films, whether for use in FERAM, RF MEMS, or other applications, are patterned by depositing blanket films and then etching away everything except for the desired functional regions. [3] Besides severely degrading the electrical properties of ferroelectric materials at and near either wet or dry chemical etch boundaries, [4,5,6] this etch process represents a serious limitation to the down-scaling of FERAM fabrication technology because of the difficulty in achieving reasonable etch anisotropy in such systems. In addition, the emergent nature of the ferroelectric response means that there must be some fundamental minimum size below which electric field-driven reversal of the spontaneous polarization will be impossible, thereby setting an absolute minimum feature size for ferroelectric memory elements.…”

Improvement in the electrical properties in Pt/Pb(Zr0.52Ti0.48)O3/Pt ferroelectric capacitors using a wet cleaning method

“…[1][2][3] Despite the large amount of effort in this field, several issues still remain to be solved for the integration of ferroelectric capacitor modules with standard silicon technology. [4][5][6][7][8][9][10][11] The major issues under current investigation are plasma damage, hydrogen-induced damage, and conductive diffusion barriers. Thus, considerable effort has been made to minimize plasma damage in connection with the undesirable effects of damaged layers.…”