A thin film capacitor includes: a metal foil having a roughened upper surface; a dielectric film covering the upper surface of the metal foil and having an opening through which the metal foil is partly exposed; a first electrode layer contacting the metal foil through the opening; a second electrode layer contacting the dielectric film without contacting the metal foil; and an insulating member separating the first and second electrode layers. The insulating member has a tapered shape in cross section. With the above configuration, both the first and second electrode layers can be disposed on the upper surface of the metal foil. In addition, since the insulating member has a tapered shape in cross section, adhesion performance of the insulating member can be enhanced, thus making it possible to prevent short-circuit between the first and second electrode layers.

To provide a thin film capacitor in which warpage is less likely to occur. A thin film capacitor includes: a metal foil having roughened upper and lower surfaces; a dielectric film covering the upper surface of the metal foil and having an opening through which the metal foil is partly exposed; a dielectric film covering the lower surface of the metal foil and made of a dielectric material having a thermal expansion coefficient smaller than that of the metal foil; a first electrode layer contacting the metal foil through the opening; and a second electrode layer contacting the first dielectric film without contacting the metal foil. The lower surface of the metal foil is thus covered with the dielectric film having a small thermal expansion coefficient, thereby making it possible to prevent the occurrence of warpage.

A semiconductor device has: a semiconductor substrate; a trench that extends from a first surface of the semiconductor substrate towards an interior of the semiconductor substrate, and that has a recess/protrusion structure on a side wall surface thereof; a semiconductor film that is formed so as to cover the side wall surface of the trench, be continuous with the side wall surface, and extend onto the first surface of the semiconductor substrate; an opposite electrode having a first portion that is provided at a position opposing the semiconductor substrate while sandwiching the semiconductor film therebetween, and that extends on the first surface of the semiconductor substrate, and a second portion that is continuous with the first portion and extends so as to fill the trench; and an insulating film that insulates the semiconductor film from the opposite electrode.

To provide a thin film capacitor having high adhesion performance with respect to a circuit substrate. A thin film capacitor includes: a metal foil having a roughened upper surface; a dielectric film covering the upper surface of the metal foil and having an opening through which the metal foil is partly exposed; a first electrode layer contacting the metal foil through the opening; and a second electrode layer contacting the dielectric film without contacting the metal foil. The first and second electrode layers are formed in an area surrounded by an outer peripheral area of the upper surface of the metal foil so as not to cover the outer peripheral area. The outer peripheral area of the roughened upper surface of the metal foil is thus exposed, so that adhesion performance with respect to a circuit substrate can be enhanced.

To provide a thin film capacitor in which a pair of terminal electrodes can be disposed on the same plane. A thin film capacitor includes a metal foil having a roughened upper surface, a dielectric film covering the upper surface of the metal foil and having an opening for partly exposing the metal foil therethrough, a first electrode layer contacting the metal foil through the opening, and a second electrode layer contacting the dielectric film without contacting the metal foil. With this configuration, both the first and second electrode layers can be disposed on the upper surface of the metal foil. In addition, since the metal foil is surface-roughened, a larger capacitance can be obtained.

To provide a thin film capacitor having high flexibility. A thin film capacitor includes: a metal foil having a roughened upper surface; a dielectric film covering the upper surface of the metal foil and having an opening through which the metal foil is partly exposed; a first electrode layer contacting the metal foil through the opening; and a second electrode layer contacting the dielectric film without contacting the metal foil. The particle diameter of crystal at a non-roughened center part of the metal foil is less than 15 μm in the planar direction and less than 5 μm in the thickness direction. This can not only enhance the flexibility of the metal foil to reduce a short-circuit failure in a state where the thin film capacitor is incorporated in a multilayer substrate but also enhance positional accuracy.

A method for fabricating a metal-insulator-metal (MIM) capacitor is provided. The MIM capacitor includes a substrate, a first metal layer, a deposition structure, a dielectric layer and a second metal layer. The first metal layer is disposed on the substate and has a planarized surface. The deposition structure is disposed on the first metal layer, and at least a portion of the deposition structure extends into the planarized surface, wherein the first metal layer and the deposition structure have the same material. The dielectric layer is disposed on the deposition structure. The second metal layer is disposed on the dielectric layer.

A semiconductor device including a substrate and a capacitor is provided. The capacitor includes a first electrode, a second electrode, and an insulating layer. The first electrode is located on the substrate. The first electrode has a plurality of hemispherical recesses. The second electrode is located on the first electrode. The insulating layer is located between the first electrode and the second electrode. Surfaces of the hemispherical recesses are in direct contact with the insulating layer.

A semiconductor device includes a landing pad and a capacitor disposed on and electrically connected to the landing pad. The capacitor includes a cylindrical bottom electrode, a dielectric layer and a top electrode. The cylindrical bottom electrode is disposed on an in contact with the landing pads, wherein an inner surface the cylindrical bottom electrode includes a plurality of protruding portions, and an outer surface of the cylindrical bottom electrode includes a plurality of concaved portions. The dielectric layer is conformally disposed on the inner surface and the outer surface of the cylindrical bottom electrode, and covering the protruding portions and the concaved portions. The top electrode is conformally disposed on the dielectric layer over the inner surface and the outer surface of the cylindrical bottom electrode.

A method for fabricating a capacitor device includes providing a substrate; forming a first-layer electrode on the substrate; and forming a conductive layer on the first-layer electrode. The roughness of the first-layer electrode is a first roughness, the roughness of the conductive layer is a second roughness, and the second roughness is smaller than the first roughness. The method further includes forming a dielectric layer on the conductive layer; and forming a second-layer electrode on the dielectric layer. According to the disclosed method and capacitor device, by forming the conductive layer on the first-layer electrode, the roughness of the bottom electrode of the capacitor device is reduced, which effectively reduces the presence of protrusions on the surface of the bottom electrode. Therefore, the breakdown electric voltage of the capacitor device may be improved, and leakage current may be avoided. As such, the reliability of the capacitor device may be improved.