HIGH-STABILITY THIN-FILM CAPACITOR AND METHOD FOR MAKING THE SAME

摘要

The dielectric of a capacitor is formed by superposition of at least two thin layers made from the same metal oxide, respectively in crystalline and amorphous form and respectively presenting quadratic voltage coefficients of capacitance of opposite signs. The respective thicknesses da and dc of the amorphous and crystalline thin layers comply with the following general formulas: d a = ɛ 0  ɛ a C s   0  ( 1 1 - ( ɛ c ɛ a ) 2  gamma a gamma c )   and   d c = ɛ 0  ɛ c C s   0  ( 1 1 - ( ɛ a ɛ c ) 2  gamma c gamma a ) in which epsilon0 corresponds to the electric constant, epsilonc and epsilona correspond to the relative permittivity of the metal oxide respectively in crystalline form and in amorphous form, Cs0 corresponds to the total surface capacitance at zero field, and gammac and gammaa correspond to the quadratic coefficient of capacitance with respect to the electric field of the metal oxide respectively in crystalline form and in amorphous form.