Semiconductor gate structure and preparation method thereof

Abstract

The invention relates to a semiconductor gate structure and a preparation method thereof. The semiconductor gate structure comprises a semiconductor substrate, the semiconductor substrate is provided with a gate trench, and a dielectric layer, a barrier layer and a metal layer are sequentially deposited in the gate trench; wherein the barrier layer is an amorphous metal nitride. The invention discloses a preparation method of a semiconductor gate structure. The preparation method comprises the following steps: etching a gate trench on a semiconductor substrate; depositing a dielectric layer on the bottom wall and the side wall of the gate trench; depositing a barrier layer on the bottom wall and the side wall of the gate trench by adopting an ALD or PEALD method, and forming the barrier layer on the surface of the dielectric layer; the barrier layer is an amorphous metal nitride; and then filling metal in the gate trench. According to the invention, the amorphous metal nitride is used as the barrier layer, so that the barrier layer is thinner and occupies smaller space, more space and more free process space are reserved for metal filling, and the difficulty of the metal filling process is reduced.

Description

technical field [0001] The invention relates to the field of semiconductor devices, in particular to a semiconductor gate structure and a preparation method thereof. Background technique [0002] Dynamic random access memory (Dynamic Random Access Memory, DRAM for short), as a well-known semiconductor storage device, is currently widely used in various electronic devices. Dynamic random access memory (DRAM) is composed of many repeated memory cells (cells). The cells are electrically connected to each other through a word line (WL for short) and a bit line (BL) for short. [0003] In order to improve the integration level of dynamic random access memory (DRAM) and speed up the operation speed of components, as well as to meet the needs of consumers for miniaturized electronic devices, the design of the transistor channel area in DRAM recently has a continuous trend of shortening, but so As a result, the transistor will have serious short channel effect and on current drop....

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Problems solved by technology

[0006] The second object of the present invention is to provide a method for preparing the above-mentioned semiconductor gate structure, which can obtain amorphous metal nitride by using ALD or PEALD method, thereby solving the problem of small selection of metal filling process

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