Fin type field-effect transistor forming method

Abstract

A fin type field-effect transistor forming method comprises the steps of providing a semiconductor substrate and a hard mask layer covering the semiconductor substrate, wherein the hard mask layer defines the fin portion of a fin type field-effect transistor; using the hard mask layer as a mask to etch a part of the semiconductor substrate to form the fin portion; forming an isolation layer covering the fin portion, wherein the surface of the isolation layer is flush with the surface of the hard mask layer; using the hard mask layer and the isolation layer as masks and forming a well region and a punchthrough-preventing region in the semiconductor substrate, wherein the punchthrough-preventing region is located at the bottom of the fin portion; etching a part of isolation layer after the well region and the punchthrough-preventing region are formed, forming a shallow-groove isolation structure, wherein the surface of the shallow-groove isolation structure is lower than the top of the fin portion. A formed fin type field-effect transistor is better in the punchthrough-preventing effect, the fin portion is better in quality, the isolation effect of the well region is better, and the performance stability of the fin type field-effect transistor is effectively improved.

Description

Technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a method for forming a fin-type field effect transistor. Background technique [0002] With the continuous development of semiconductor process technology, process nodes are gradually reduced, high-K dielectric layers and metal gate electrodes have been widely used, and by forming metals with different work functions between the high-k dielectric layer and the metal gate electrode Obtain ideal threshold voltage and improve device performance. However, when the feature size (CD, Critical Dimension) of the device is further reduced, the structure of the conventional MOS field effect transistor can no longer meet the requirements for device performance, and the fin field effect transistor (Fin FET) has been replaced as a conventional device. Widespread concern. [0003] figure 1 The three-dimensional schematic diagram of a fin-type FET in the prior art is shown. Such...

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Problems solved by technology

[0004] However, with the further shrinking of the process node, the performance stability of the fin field effect transistor formed by the existing technology needs to be further improved

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