Abstract: A semiconductor memory wherein a part of each capacitor is formed on side walls of an island region surrounded with a recess formed in a semiconductor substrate, and the island region and other regions are electrically isolated by the recess.

Abstract: A semiconductor memory device having STC cells wherein major portions of active regions consisting of channel-forming portions are tilted at an angle of 45.degree. with respect to the word lines and the bit lines that meet at right angles with each other, enabling the storage capacity portions to be arranged very densely and sufficiently large capacities to be maintained with very small cell areas. In the semiconductor memory device, furthermore, the storage capacity portions are formed even on the bit lines. Therefore, the bit lines are shielded, the capacitance between the bit lines decreases, and the memory array noise decreases.

Abstract: A semiconductor memory comprises a switching device and a charge-storage device disposed at the upper and lower sides, respectively, of each of semiconductor islands. The islands are formed on a semiconductor substrate that is completely isolated from the semiconductor substrate by an insulator. The switching device and charge-storage device are substantially the same width. The memory cell structure is extremely small. The cell structure is highly resistant to alpha-particles and is formed self-aligned. During manufacture, the SiO.sub.2 island is oxidized adjacent its lower end to insulate the island from the substrate.

Abstract: A semiconductor memory comprises a capacitor with a data storage portion, and an insulated-gate field-effect transistor. The capacitor is formed by a plate which is made up of the side walls and base of a groove formed in a semiconductor substrate, and by a capacitor electrode formed on the side walls and the base, over an insulation film, and which is connected electrically to the source or drain of the insulated-gate field-effect transistor. Various embodiments are provided for reducing size and preventing leakage between other memory cells, including forming stacked capacitors, forming the transistor over the capacitor, using a silicon-over-insulator arrangement for the transistor, forming a common capacitor plate and providing high impurity layers within the substrate.

Abstract: A semiconductor memory wherein a memory cell region having a plurality of memory cells and has higher altitude from the surface of semiconductor substrate is formed in the recessed part of semiconductor substrate having the recessed part and projected part and a peripheral circuit region which is comparatively low from the surface of semiconductor substrate is formed to the projected part of semiconductor substrate.

Abstract: An insulation film on silicon buried in a trench is prepared by forming a field oxide film by using a first Si.sub.3 N.sub.4 mask formed on a silicon substrate, forming a second Si.sub.3 N.sub.4 mask for formation of a trench, forming a trench in the silicon substrate by using the second Si.sub.3 N.sub.4 mask, burying polycrystalline silicon in the trench, removing the second Si.sub.3 N.sub.4 mask while leaving the first Si.sub.3 N.sub.4 mask and oxidizing the surface of the polycrystalline silicon buried in the trench by thermal oxidation. The so-formed insulation film on silicon buried in the trench has a uniform thickness and a high dielectric strength. The surface of the substrate at a part where an active element will be formed in the future is not oxidized.

Abstract: A semiconductor memory having static cells each composed of two driver MOS transistors formed on a semiconductor substrate and two transfer MOS transistors and two load resistors, which are formed on the substrate and are connected to the drains of the driver MOS transistors, respectively. A conductive film for fixing the sources of the driver MOS transistors to a ground voltage is formed above the principal surface of the semiconductor substrate, and this conductive film defines one electrode of a capacitance element formed on the substrate. The conductive film is formed over the load resistors formed on the semiconductor substrate so as to constitute an electric field shield for the load resistors.

Abstract: A semiconductor memory wherein a part of each capacitor is formed on side walls of an island region surrounded with a recess formed in a semiconductor substrate, and the island region and other regions are electrically isolated by the recess.

Abstract: A dry-etching gas suitable for selective etching of silicon nitride and a process for selectively dry-etching silicon nitride with the dry-etching gas are disclosed. Silicon nitride can be dry-etched with a higher selectivity or at a higher etching rate than silicon dioxide and silicon, and a process for fabricating semi-conductor devices can be simplified and devices with a novel structure can be realized.