Study and optimization of alumina and germanium dioxide and their multilayer capacitor properties

To better understand the dielectric properties of alumina and germanium dio xide multilayer capacitors, a very extensive investigation is undertaken on the characteristics of each material. The thin layers of these oxides are obtained by radio-frequency (RF) cathodic sputtering. An optimization of th e dielectric properties of these materials has been done in two steps: firs t, the analysis of the composition of the alumina and that of the germanium dioxide by the RES technique has allowed the determination of the best con ditions of sputtering which will give good dielectric properties. These pro perties have been improved by thermal treatments. In addition, samples rehe ated in three cycles from 20 degrees C to 200 degrees C for two or three da ys went through other thermal cycles (20 degrees C to -180 degrees C, appro ximately). These studies and investigations confirmed the influence of the sputtering conditions on the dielectric properties. The thermal treatments were found to improve the dielectric properties. The dielectric multilayer capacitors have a breakdown field superior to that of each simple layer. (C ) 2000 Elsevier Science B.V. All rights reserved.