AVS 47th International Symposium
    Electronics Tuesday Sessions
       Session EL-TuP

Paper EL-TuP11
Electrical Properties of (Ba,Sr)TiO@sub 3@ Capacitors by Inductively Coupled Plasma Etching

Tuesday, October 3, 2000, 5:30 pm, Room Exhibit Hall C & D

Session: Poster Session
Presenter: S.-K. Choi, Chungang University, Korea
Authors: S.-K. Choi, Chungang University, Korea
N.-H. Kim, Chungang University, Korea
E.-G. Chang, Chungang University, Korea
T.-H. Kim, YIT, Korea
C.-I. Kim, Chungang University, Korea
Correspondent: Click to Email
Recently, (Ba,Sr)TiO@sub 3@ high dielectric thin films have received much attention as a new dielectric material for high density dynamic random access memories (DRAMs) because of their high relative dielectric constant and small variation in dielectric properties with frequency. It is well known that BST films are difficult to be etched, but good etch rate with high selectivity to etch mask was obtained by result of our former study.@footnote 1@ However, It was scarcely verified the possibility of etched thin films under these conditions for the appliance of practical devices. In this study, high density plasmas etching damage to the electrical properties of Pt/(Ba,Sr)TiO@sub 3@/Pt high dielectric capacitors was evaluated under Ar bombardment and Ar/Cl@sub 2@/BCl@sub 3@ etch plasmas. And the etch parameters were changed as gas mixing ratio, coil rf power, dc bias voltage and chamber pressure. Capacitance and leakage current of BST capacitors, before and after etching, are compared to examine the etching damage. The capacitance and dielectric dissipation factors were measured by using an HP 4192 impedance/gain-phase analyzer at 10 kHz, and the leakage current density was determined by using an HP 4145B semiconductor parameter analyzer. The change of capacitance and leakage current represented the physical effect of ion bombardment. The crystal structure of the etched samples was investigated by x-ray diffraction (XRD) to observe the variation of phases. The improved etching condition with the consideration of capacitance and leakage current of BST capacitor could be obtained by analyzing correlation between electrical properties and various etching parameters. . @FootnoteText@ @footnote 1@ S.-B. Kim, Y.-H. Lee, T.-H. Kim, G.-Y. Yeom, and C.-I. Kim, J. Vac. Sci. Technol. A 18, 2000. To be published.