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

Paper EL-TuP13
Etching Mechanism of Y@sub 2@O@sub 3@ Thin Flims in Cl@sub 2@/Ar Plasma

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

Session: Poster Session
Presenter: Y.C. Kim, Chungang University, Korea
Authors: Y.C. Kim, Chungang University, Korea
B.J. Min, Chungang University, Korea
Y.T. Kim, KIST, Korea
C.-I. Kim, Chungang University, Korea
Correspondent: Click to Email
Many researchers have proposed to insert such buffer layers as Y@sub 2@O@sub 3@ and CeO@sub 2@ for ferroelectric gate structures. In particular, Y@sub 2@O@sub 3@/Si shows excellent interface properties and ferroelectrics deposited on Y@sub 2@O@sub 3@ film show excellent fatigue characteristics. The dielectric constant of Y@sub 2@O@sub 3@ film ranges from 14 to 17. Hence, Y@sub 2@O@sub 3@ films are expected to be used a buffer layer in the ferroelectric gate structure. In this study, etching mechanism of Y@sub 2@O@sub 3@ thin film was systematically investigated by using inductively coupled Cl@sub 2@/Ar plasma. Etching characteristics of the Y@sub 2@O@sub 3@ thin film were investigated by using plasma diagnostic tools in conjunction with the surface analysis after etching. The etch rate of Y@sub 2@O@sub 3@ film, and selectivity of Y@sub 2@O@sub 3@ film to PR and SiO@sub 2@ were examined as functions of Cl@sub 2@/Ar gas mixing ratio, coil rf-power, dc bias voltage, chamber pressure, and substrate temperature. The etched surface of Y@sub 2@O@sub 3@ film was examined with x-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS). The etch profile of Y@sub 2@O@sub 3@ film was examined with scanning electron microscopy (SEM). The concentrations of the etching species in the plasma were determined by using optical emission spectroscopy (OES). Plasma potential and floating potential, electron density and ion current density in the plasma were determined by using Langmuir probe. Y@sub 2@O@sub 3@ film was more effectively etched by Ar ion bombardment than by chemical reaction with Cl radical, but the etch rate of Y@sub 2@O@sub 3@ film was enhanced by chemical reaction with Cl radical. In this study, for the first time, we introduced the use of Cl@sub 2@/Ar plasma system in Y@sub 2@O@sub 3@ etching.