AVS 53rd International Symposium
    Electronic Materials and Processing Thursday Sessions
       Session EM-ThP

Paper EM-ThP45
Electrical and Chemical Analyses of SrTiO@sub 3@/Y@sub 2@O@sub 3@ MIM Capacitors

Thursday, November 16, 2006, 5:30 pm, Room 3rd Floor Lobby

Session: Electronic Materials and Processing Poster Session
Presenter: C. Vallee, LTM/CNRS, France
Authors: C. Vallee, LTM/CNRS, France
M. Kahn, LTM/CNRS, France
E. Defay, LTM/CNRS, France
C. Dubourdieu, LTM/CNRS, France
M. Bonvalot, LTM/CNRS, France
O. Joubert, LTM/CNRS, France
Correspondent: Click to Email
The voltage linearity of MIM capacitors is usually described by the following equation: @DELTA@C/C = (C(V)-C0)/C0 = ?V2 + ?V , where C0 is the capacitance value at zero applied voltage, and ? and ? are the quadratic and linear coefficients of the capacitance. According to ITRS specifications, ? must be less than 100 ppm/V2 for RF bypass devices and ? should be as small as possible. As of this date, none of the dielectric materials put on trial for MIM applications shows acceptable voltage linearity with high capacitance density value, their C(V) curve having either a positive or a negative bending. An experimental strategy consists in elaborating bi-layer of dielectric materials exhibiting opposite voltage linearity behaviour. By tuning the thickness of these two dielectrics with respect to each other, we expect to adjust their relative contribution to the overall ? value. Thus, perfectly stable capacitance density values should be observed with varying applied voltage. In this study, SrTiO3 (STO)-Y2O3 bilayer MIM capacitors are developed. Indeed, STO and Y2O3 show respectively negative and positive ?. STO layers with several thicknesses have been prepared by dual ion beam scattering (DIBS) on Pt/TiO2/SiO2/Si stacks. A post deposition annealing treatment is carried out in order to induce crystallisation. Y2O3 layers are deposited by pulsed injection PE-MOCVD. Metal-dielectric and dielectric-dielectric interfaces are analyzed by XPS, XRR and SE in the FUV range. These dielectrics are then electrically characterized by C(V) measurements with gold electrodes in order to extract ? values and to estimate the overall dielectric constant.