Patent ID: 6605515
Filing Date: 2003-08-12
Classification: H01L

Abstract:
A method for manufacturing a thin-film capacitor having a desired sheet capacitance and a desired temperature coefficient of capacitance by depositing a first dielectric thin-film having a temperature coefficient of capacitance with an absolute value of 50 ppm/Â° C. or less and a second dielectric thin-film having a negative temperature coefficient of capacitance, wherein the second dielectric thin-film has a structure composed of an aggregation of principal grain units each having a principal crystal grain and grain boundary layers surrounding the principal crystal grain, includes a plurality of principal grain units, and has a thickness tN, wherein tN={âˆˆ0&tgr;t0t/(C/S)}Â·{1/(&tgr;/&kgr;)}, (C/S represents the sheet capacitance, âˆˆ0&tgr;t0t represents the desired temperature coefficient of capacitance), wherein &tgr; represents the temperature coefficient of capacitance of the second dielectric thin-film, and &kgr; represents the relative dielectric constant of the second dielectric thin-film, the method comprising:determining a target value of a grain size of the second dielectric thin-film by selecting the grain size satisfying the formula (&tgr;/&kgr;)/(&tgr;g/&kgr;g)>1, wherein (&tgr;g/&kgr;g) represents the ratio (&tgr;/&kgr;) of the principal crystal grain, and depositing the second dielectric thin-film so that the grain size becomes the target value to reduce the thickness of the second dielectric thin-film.