Abstract: Disclosed is a semiconductor device, comprising a substrate having a first region and a second region surrounding the first region, a MOS transistor formed in the first region, a first conductive layer formed in the first region and constituting the lower layer of a two-layered gate electrode of the MOS transistor, a second conductive layer for isolation, the second conductive layer being formed in the second region and having an upper surface whose level is lower than that of the upper surface of the first conductive layer, a first insulating layer formed between the first and second regions, a second insulating layer formed on the second conductive layer, and a third conductive layer formed over the first conductive layer and the second insulating layer and constituting the upper layer of the two-layered gate electrode of the MOS transistor.

Abstract: Element isolation technique for LSIs having a fine pattern of sub-micron class or finer. A high strained region doped with impurities at a high concentration is formed under, and remote from, a buried insulating material (dielectrics) layer for element isolation. With this buried dielectrics element isolation (BDEI) structure, since the high strained layer exists just under the buried dielectrics layer, crystal defects generated near the buried dielectrics layer due to strain caused by a difference of thermal expansion coefficient between a semiconductor layer and the buried dielectrics layer, are moved toward the high strained layer. Accordingly, the crystal defects do not reach an active region where active elements are formed, so that leakage current in the p-n junction formed in the active layer can be advantageously reduced.

Abstract: A semiconductor device has a semiconductor substrate having a groove, and a semiconductor element formed in a surface region of the semiconductor substrate. A substance having a thermal expansion coefficient different from the semiconductor substrate is embedded in at least a portion of the groove, a crystal defect is generated from the region near the bottom of the groove in the semiconductor substrate, thereby alleviating stress and strain in other regions of the semiconductor substrate, such that such regions cannot generate crystal defects in a region necessary for a circuit operation of the semiconductor element of the surface region.

Abstract: A semiconductor device includes an underlying layer formed by a first insulation layer, a plurality of island semiconductor layers formed on the first insulation layer, source and drain regions formed in each of the island semiconductor layers, a first gate electrode formed between the source and drain regions and formed on and insulated from the island semiconductor layer, a second insulation layer formed on the sides of the island semiconductor layer and along the periphery of the first gate electrode, the second insulation layer being higher than the surface of the island semiconductor layer and lower than the surface of the first gate electrode, and a second gate electrode formed over both the first gate electrode and the second insulation layer.

Abstract: A groove, which runs vertically and horizontally, is formed in a substrate, thereby a plurality of silicon pillars are formed in a matrix manner. A field oxidation film is formed on the central portion of the groove. A drain diffusion layer is formed on the upper portion of each silicon pillar, and a source diffusion layer is formed on the bottom portion of the groove. A gate electrode, serving as a word line, a storage node contacting the source diffusion layer, and a cell plate are sequentially buried to enclose the surroundings of each silicon pillar, and a bit line is formed in an uppermost layer, thereby a DRAM cell array is structured.

Abstract: A groove, which runs vertically and horizontally, is formed in a substrate, thereby a plurality of silicon pillars are formed in a matrix manner. A field oxidation film is formed on the central portion of the groove. A drain diffusion layer is formed on the upper portion of each silicon pillar, and a source diffusion layer is formed on the bottom portion of the groove. A gate electrode, serving as a word line, a storage node contacting the source diffusion layer, and a cell plate are sequentially buried to enclose the surroundings of each silicon pillar, and a bit line is formed in an uppermost layer, thereby a DRAM cell array is structured.