Abstract: A method for fabricating a trench capacitor with an insulation collar in a substrate, which is electrically connected to the substrate on one side via a buried contact, using a hard mask with a corresponding mask opening.

Abstract: A method for eching a recess in a polysilicon region of a semiconductor device by applying a solution of NH4OH in water to the polysilicon.

Abstract: In order to form an oxide cover on a conductive filling in a trench in a semiconductor substrate an HDP oxide is deposited on the conductive filling using a PECVD method. In this case, the layer thickness on the horizontal surface of the conductive material is greater than the layer thickness on the sidewalls of the trench. Furthermore, the layer thickness is limited in such a way that the surface of the HDP oxide within the trench has a depth with respect to the surface of the semiconductor substrate surrounding the trench, or a layer disposed thereon. In a subsequent CMP step, the HDP oxide is removed from the surrounding surface. In an isotropic etching step, the HDP oxide is removed from the sidewalls. The result is a horizontal insulation layer with a layer thickness that varies only to a slight extent over the semiconductor substrate.

Abstract: A memory cell has a trench capacitor, in which the area required over a terminal area of the trench capacitor is advantageously reduced by the formation of a particularly thin insulation collar. The insulation collar is reduced to such an extent that although a lateral current is prevented, the formation of a parasitic field-effect transistor is permitted. In order that, however, overall no current flows via the parasitic field-effect transistor, a second parasitic field-effect transistor is disposed in a manner connected in series, but is not turned on. This is achieved by the formation of a thicker second insulation collar that isolates the filling of the trench capacitor from the surrounding substrate.

Abstract: In semiconductor memories, in particular DRAMs, the memory cells of which have vertical transistors at vertical lands formed from substrate material, gate electrodes are formed as spacers which run around the land. The gate electrodes of adjacent memory cells conventionally have to be retroactively connected to form word lines. It is known to fill spaces between adjacent lands with an oxide, with the result that the spacers are formed directly as word lines but only cover two side walls of a land. Two transistors which are connected in parallel are formed at these side walls instead of a single transistor, since the gate electrode does not run around the land. The invention proposes a method for fabricating a semiconductor memory in which all four side walls of a land are covered by the word lines and at the same time lands of adjacent memory cells are connected to one another by the word lines.

Abstract: A method for etching a recess in a polysilicon region of a semiconductor device by applying a solution of NH4OH in water to the polysilicon.

Abstract: A semiconductor memory cell configuration includes dynamic memory cells respectively having a trench capacitor and a vertical selection transistor, the memory cells being disposed in matrix form, the trench capacitors and the associated vertical selection transistors following one another in each case in the form of rows and/or columns.

Abstract: A ring oscillator has a multiplicity of inverters. An interconnect is connected between two of the inverters, and a storage capacitor to be measured, with its associated lead resistor, is coupled to the interconnect either via an interconnect or a transistor can selectively coupled and decouple the capacitor and the lead resistance. A measuring device is connected up to the ring oscillator and is used to determine a value for the oscillation frequency of the ring oscillator on the basis of which a value for the time constant of the storage capacitor can be determined.

Abstract: A semiconductor component has a cavity formed in a monocrystalline silicon substrate. The wall of the cavity is covered by a cover layer, at least in an upper collar region, and a covering layer is then applied to the surface of the silicon substrate using a selective epitaxial growth method. The cavity is thereby covered in the process. The method is physically simple and can be carried out cost-effectively. In particular, the described method can be used in order to cover a trench prior to high-temperature processes during the production of a DRAM memory, and to open the trench once again after the high-temperature processes, in order to provide a trench capacitor.

Abstract: A mask is fabricated by applying a sacrificial layer on a semiconductor wafer. The sacrificial layer is then processed with the aid of a first and a second lithographic process sequence in order to pattern the sacrificial layer in a first and a second direction. A hard mask layer is subsequently applied in order to completely enclose the patterned sacrificial layer. Finally, the sacrificial layer is then removed from the hard mask layer.

Abstract: A ring oscillator has a multiplicity of inverters. An interconnect is connected between two of the inverters, and a storage capacitor to be measured, with its associated lead resistor, is coupled to the interconnect either via an interconnect or a transistor can selectively coupled and decouple the capacitor and the lead resistance. A measuring device is connected up to the ring oscillator and is used to determine a value for the oscillation frequency of the ring oscillator on the basis of which a value for the time constant of the storage capacitor can be determined.