Semiconductor device structure and preparation method thereof

Abstract

The invention provides a semiconductor device structure and a preparation method thereof, and the preparation method comprises the steps of providing a semiconductor substrate, and forming a pluralityof active regions and an isolation structure for isolating the active regions, wherein each active region comprises a first contact region and a second contact region; forming a plurality of gate trench structures in the active regions based on different etching selection ratios among different materials so as to separate the first contact region from the second contact region, wherein each gatetrench structure comprises a trench main body and a micro-trench structure, and the maximum depth of each gate trench structure is smaller than the depth of the isolation structure; and forming a gatedielectric layer on the inner surfaces of the gate trench structures, and filling a gate electrode layer in the gate trench structures to form an embedded gate word line structure. According to the invention, a special micro-channel structure is formed through different etching selection ratios among different materials, the preparation process is simplified, the preparation precision is improved, the channel area is increased on the basis of keeping the size of an original device, the width of a transmission channel can be further increased, and the device performance of a field effect transistor is improved.

Description

technical field [0001] The invention belongs to the technical field of integrated circuit manufacturing, and in particular relates to a semiconductor device structure and a preparation method thereof. Background technique [0002] With the evolution of semiconductor manufacturing process and the continuous shrinking of the feature size of semiconductor devices, for field effect transistors, due to the short channel effect, large sub-threshold current and gate leakage, it is difficult for transistors to meet the requirements of device performance. Now more and more attention is focused on the Fin Field Effect Transistor (Fin FET). [0003] Transistors are used in many different types of integrated circuits. The common ones are: logic devices, storage devices and analog circuits. Among them, storage devices account for a considerable proportion of integrated circuit products. The basic structure of memory is a transistor plus a capacitor structure. The transistors used are bu...

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Problems solved by technology

[0006] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a semiconductor device structure and its preparation method, which are used to solve the problems of the transistor performance that is difficult to meet the demand and the driving voltage and on-current drop in the prior art.

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