Dynamic random access memory and its manufacturing method

Abstract

A dynamic random access memory and a manufacturing method thereof. The dynamic random access memory includes a silicon substrate, a first isolation trench structure, a second isolation trench structure, an active area defined by the first and second isolation trench structures, located at Buried word lines in the silicon substrate, buried bit lines and capacitors in the silicon substrate. Two buried word lines are disposed between two second isolation trench structures to divide the active area into a bit line contact window and two capacitor contact windows located between the two buried word lines. The buried bit line is located above the buried word line and is electrically connected to the bit line contact window in the active area. The capacitor is arranged on the active area and is electrically connected to the capacitor contact window. There is also an oxide liner between the buried bit line and the silicon substrate. The present invention can improve the read margin of DRAM.

Description

technical field [0001] The present invention relates to a dynamic random access memory technology, and in particular to a dynamic random access memory and a manufacturing method thereof. Background technique [0002] The dynamic random access memory (DRAM) faces more and more difficulties after the development of the device into the nanometer era, for example, the sensing margin becomes smaller. Currently, there are three key technologies for improving the read margin, including larger storage capacitance, smaller capacitance between bit lines (BL capacitance, Cb) and smaller noise. According to the current DRAM manufacturing process, since the distance between the capacitors can no longer be reduced, it is not easy to improve the read margin by increasing the storage capacitor. [0003] Therefore, there is an urgent need to find other ways to improve the readout margin of DRAM after the nanometer era. Contents of the invention [0004] The invention provides a dynamic r...

AI Technical Summary

Problems solved by technology

Judging from the current DRAM manufacturing process, because the distance between capacitors can no longer be reduced, it is not easy to improve the read margin by increasing the storage capacitor

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