Semiconductor structure, manufacturing method thereof and DRAM

Abstract

The invention relates to a semiconductor structure, a manufacturing method thereof and a DRAM (Dynamic Random Access Memory), and belongs to the technical field of semiconductors, thereby solves problems of short opening effect, current leakage and relatively large RC (Resistance-Capacitance) delay caused by size reduction of a transistor in the prior art. The semiconductor structure includes: a semiconductor substrate, a gate trench, a gate dielectric layer, a gate conductor layer, an isolation layer, and an air side wall. The gate trench is located in the semiconductor substrate, the gate trench comprises an upper part and a lower part, and the width of the connecting position of the upper part and the lower part is concave inwards relative to other parts of the gate trench; the gate dielectric layer is located on the inner wall of the gate trench; a gate conductor layer in the lower part; the isolation layer is located in the upper part, and the bottom of the isolation layer is in contact with the gate conductor layer; and the bottom of the isolation layer is separated at two sides of the gate conductor layer, so that the air side wall is formed between the gate conductor layer and the gate dielectric layer. The short opening effect is improved, the current leakage is reduced, and the RC delay of the word line can be reduced by adding the air side wall.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a semiconductor structure, a manufacturing method thereof and a DRAM. Background technique [0002] Memory is a device or component used to store a large amount of information in a digital system, and is an important part of computers and digital devices. Memory can be divided into two categories: Random Access Memory (RAM) and Read Only Memory (ROM). RAM includes DRAM, PRAM, MRAM, etc., and transistors are one of the key components for manufacturing these RAMs. The gate of the transistor is used to control the current flow between the source and drain. Ideally, when a suitable voltage is applied to the gate, a current is generated between the source and the drain; otherwise, when the gate voltage is not applied, the current between the source and the drain is turned off. [0003] However, as the integration level of RAM continues to increase, the size of transistors co...

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Problems solved by technology

[0005] In view of the above analysis, the embodiment of the present invention aims to provide a semiconductor structure, its manufacturing method and DRAM to solve the problems of short opening effect and current leakage caused by the size reduction of existing transistors

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