Semiconductor memory device and forming method thereof

Abstract

The invention discloses a semiconductor memory device and a forming method thereof. The semiconductor memory device includes a substrate, a plurality of gates, a plurality of bit lines, and dummy bitlines. The plurality of gates are arranged in the substrate in a first direction. The bit lines are arranged on the substrate in the second direction, the dummy bit lines are arranged on the outer sides of the bit lines in the second direction, a plurality of protruding parts are arranged on one side walls of the dummy bit lines, the protruding parts extend from the top faces of the bit lines to the bottom faces of the bit lines, and the protruding parts have the same length in the second direction. Therefore, the protruding parts can be used for isolating the gates extending out of the bit lines, and the semiconductor storage device with better assembly reliability is formed under the condition of simplifying the manufacturing process.

Description

technical field [0001] The present invention relates to a semiconductor device and its forming method, in particular to a semiconductor storage device and its forming method. Background technique [0002] With the trend of miniaturization of various electronic products, the design of dynamic random access memory (DRAM) units must also meet the requirements of high integration and high density. For a DRAM cell with a recessed gate structure, because it can obtain a longer carrier channel length in the same semiconductor substrate to reduce the leakage of the capacitor structure, it is under the current mainstream development trend , which has gradually replaced DRAM cells with only planar gate structures. [0003] Generally, a DRAM cell with a recessed gate structure includes a transistor device and a charge storage device to receive voltage signals from bit lines and word lines. However, due to the limitation of process technology, the existing DRAM cells with recessed gat...

AI Technical Summary

Problems solved by technology

However, limited by the process technology, there are still many defects in the existing DRAM cells with recessed gate structures, which need to be further improved to effectively improve the performance and reliability of related memory components

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