Memory device and method for fabricating the same

Abstract

Disclosed are a memory device and a method for fabricating the same. The memory device includes: a substrate provided with a trench; a bit line contact junction formed beneath the trench; a plurality of storage node contact junctions formed outside the trench; and a plurality of gate structures each being formed on the substrate disposed between the bit line contact junction and one of the storage node contact junctions. Each sidewall of the trench becomes a part of the individual channels and thus, channel lengths of the transistors in the cell region become elongated. Accordingly, the storage node contact junctions have a decreased level of leakage currents, thereby increasing data retention time.

Description

technical field [0001] The present invention relates to a memory device and a manufacturing method thereof, and more particularly, to a memory device capable of improving data retention time and a manufacturing method thereof. Background technique [0002] As semiconductor devices have been increasingly miniaturized, the size of each pattern has been gradually reduced. Especially in memory devices such as dynamic random access memory (DRAM) devices, due to large-scale integration, the length of the gate electrode is drastically reduced in proportion to the reduction in transistor size in the cell region, and as a gate As a result of the reduction in electrode size, the junction of the source and drain has played an important role in the electric field and potential applied to the body of the transistor in the cell. [0003] FIG. 1 is a cross-sectional view illustrating the structure of a conventional memory device. [0004] As shown, a field oxide layer 120 for isolating d...

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Problems solved by technology

However, due to excessive ion implantation for obtaining a high doping concentration, the edge region A of the storage node contact junction 170B in the cell region will have a high level of electric field, and thus, the junction leakage current at the junction portion of the storage node contact junction 170B increases.

Such an increase in junction leakage current causes a decrease in data retention time, that is, degradation of the recovery characteristics of the memory device

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