Groove capacitor and its manufacture

Abstract

A method for fabricating a trench capacitor in a semiconductor substrate with a low-impedance inner electrode for use in memory cells of memory devices. A separating layer is provided on a dielectric layer in the active region of the trench capacitor. Afterward, a low-impedance inner electrode made of metal or a metal compound is introduced both in the active region and in the collar region lined with an insulation layer.

Description

technical field [0001] The present invention relates to a method for manufacturing a trench capacitor in a semiconductor substrate, wherein a hole trench is introduced into the semiconductor substrate from a substrate surface, and a External electrodes are provided in a section of the semiconductor substrate adjacent to the hole trench, furthermore, the hole trench is lined with a dielectric layer in an active region extending into the semiconductor substrate, and A collar region between the substrate surface and the active region is lined with an insulating layer. Additionally, the present invention is additionally related to a trench capacitor. Background technique [0002] When manufacturing semiconductor circuit devices such as DRAM (Dynamic Random Access Memory, dynamic random access memory) memory devices, one of the main considerations is, for example, to increase the bulk density. Usually, in this case, it is an attempt to To increase the number of switching elemen...

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Problems solved by technology

At this point in time, the internal electrodes consist of systems having a resistance in the range below 1000 x 10 -6 ohms / cm of doped polysilicon, and since the resistance depends on the cross-sectional area of ​​a conductor, one of the trench capacitor structures is further miniaturized, and thus the miniaturization of the internal electrodes leads to the internal A very high non-reactive resistance of the electrodes and, resulting in the electrically active section of the inner electrode being lower than the neck region

[0005] A disadvantage with the various proposals to provide a low-resistance material, such as, for example, a metal or a metal compound, as the internal electrode is that a direct contact between the metal and the storage dielectric would lead to chemical reactions that damage the dielectric, so, hitherto, it has been customary that only the neck region of the hole trench is filled with a metal, and the active part of the trench capacitor comprising the storage dielectric area is still provided with a polysilicon fill

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