Patent ID: 8952491
Filing Date: 2015-02-10
Classification: H01L

Abstract:
1. A capacitive element comprising: an upper electrode; a lower electrode; concavity and convexity formed on an upper surface of the lower electrode; and a dielectric layer that is disposed between the upper electrode and the upper surface of the lower electrode, and includes a first film, a second film and a third film which are made of any one of silicon nitride and aluminum oxide and laminated from a side of the lower electrode in order, a composition ratio of any one of silicon and aluminum in each of the first film and the third film being larger than a corresponding composition ratio in the second film, wherein the first film and the third film are made of silicon nitride, and composition ratios of silicon in a part of the first film in contact with the lower electrode and a part of the third film in contact with the upper electrode are equal to or more than 0.8, or the first film and the third film are made of aluminum oxide, and composition ratios of aluminum in a part of the first film in contact with the lower electrode and a part of the third film in contact with the upper electrode are equal to or more than 0.7, and wherein the composition ratio of any one of silicon and aluminum in the first film increases continuously or stepwise toward the lower electrode, and the composition ratio of any one of silicon and aluminum in the third film increases continuously or stepwise toward the upper electrode.