Dynamic random access memory and preparation process thereof

Abstract

The invention provides a dynamic random access memory which comprises a substrate, a capacitor, conductive columns, an isolation dielectric layer and a transistor, the capacitor comprises a semiconductor deep groove capacitor structure and a dielectric deep groove capacitor structure, one part of the semiconductor deep groove capacitor structure is arranged in the substrate, the other part of the semiconductor deep-groove capacitor structure is arranged in the isolation dielectric layer, the semiconductor deep-groove capacitor structure is electrically contacted with the transistor, the dielectric deep-groove capacitor structure is arranged in part of the isolation dielectric layer, and the dielectric deep-groove capacitor structure is connected with the semiconductor deep-groove capacitor structure in parallel. Therefore, the capacitance value of the dynamic random access memory is improved, and the etching depth of the capacitor in the substrate is reduced. The number of the conductive columns is several, and the conductive columns are respectively in electrical contact with the transistors and the dielectric deep groove capacitor structure so as to form a global electrical interconnection structure. The invention also provides a preparation process of the dynamic random access memory.

Description

technical field [0001] The invention relates to the technical field of semiconductor storage, in particular to a dynamic random access memory and a preparation process thereof. Background technique [0002] Dynamic Random Access Memory (Dynamic Random Access Memory, DRAM) is a common random access memory, and DRAM can only hold data for a short time. In order to keep the data, DRAM must be refreshed every once in a while. If the storage unit is not refreshed, the data will be lost. Because of this feature that requires regular refresh, it is called "dynamic" memory. [0003] At present, the industry generally adopts a structure of a transistor and a capacitor as a DRAM unit. This combination of 1T1C components makes the storage bit of DRAM the electronic component with the highest density and the lowest unit manufacturing cost, and has an irreplaceable position in computer access devices. With the rapid development of semiconductor technology, DRAM components are rapidly d...

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Problems solved by technology

The inventive method uses doping and epitaxy techniques to alternately grow N-type SiGe layers and N-type Si layers and uses selective etching to produce comb-shaped sidewalls. The structure and process are complex, and the semiconductor substrate described in the patent is only It plays a supporting role, and its semiconductor substrate is not fully utilized, which constitutes waste of materials and high cost investment

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