Abstract: According to one embodiment, a nitride semiconductor device has an electroconductive substrate, a first nitride semiconductor layer provided directly on the electroconductive substrate or provided on the electroconductive substrate through a buffer layer and formed of a non-doped nitride semiconductor, a second nitride semiconductor layer provided on the first nitride semiconductor layer and formed of a non-doped or n-type nitride semiconductor having a band gap wider than that of the first nitride semiconductor layer, a heterojunction field effect transistor having a source electrode, a drain electrode, and a gate electrode, a Schottky barrier diode having an anode electrode and a cathode electrode, first and second element isolation insulating layers, and a frame electrode. The frame electrode is electrically connected to the source electrode and the electroconductive substrate, and surrounds outer peripheries of the heterojunction field effect transistor and the Schottky barrier diode.

Abstract: Methods of forming conductive pattern structures form an insulating interlayer on a substrate that is partially etched to form a first trench extending to both end portions of a cell block. The insulating interlayer is also partially etched to form a second trench adjacent to the first trench, and a third trench extending to the both end portions of the cell block. The second trench has a disconnected shape at a middle portion of the cell block. A seed copper layer is formed on the insulating interlayer. Inner portions of the first, second and third trenches are electroplated with a copper layer. The copper layer is polished to expose the insulating interlayer to form first and second conductive patterns in the first and second trenches, respectively, and a first dummy conductive pattern in the third trench. Related conductive pattern structures are also described.

Abstract: A semiconductor device is disclosed. The semiconductor device includes a semiconductor substrate; a gate insulating film formed above the semiconductor substrate; a charge storage layer formed above the gate insulating film; a multilayered interelectrode insulating film formed in a first region above an upper surface portion of the element isolation insulating film, a second region above a sidewall portion of the charge storage layer and a third region above an upper surface portion of the charge storage layer, the interelectrode insulating film including a stack of an upper silicon oxide film, a middle silicon nitride film, and a lower silicon oxide film; a control gate electrode formed above the interelectrode insulating film; wherein the middle silicon nitride film is thinner in the third region than in the second region and the upper silicon oxide film is thicker in the third region than in the second region.