MOSFET element and preparation method

Abstract

The invention relates to an MOSFET element and a preparation method. The preparation method comprises the following steps of providing a semiconductor substrate, forming a gate structure and LDD areas located at the two sides of a gate electrode on the semiconductor substrate, forming gate interval walls at the two sides of the gate structure, etching the substrate to form a groove in the position, where a source drain area is formed, of the substrate, forming an oxide insulation layer on the surface of the groove, depositing an oxide mask layer on the oxide insulation layer, depositing silicon oxide on the oxide mask layer, etching the silicon oxide with only the silicon oxide on the lateral wall, near the gate side, of the groove reserved, etching the oxide mask layer in an isotropic mode with the silicon oxide as a mask, removing the silicon oxide and the oxide insulation layer not covered by the oxide mask layer in a wet etching mode, removing the residual oxide mask layer, growing silicon inside the groove in an epitaxy mode, and forming the source drain area. The preparation method can well remove the shallow trench effect.

Description

technical field [0001] The invention relates to the field of transistor preparation, in particular, the invention relates to a MOSFET device and a preparation method. Background technique [0002] Metal-Oxide-Semiconductor-Field-Effect Transistor (MOSFET) is a field-effect transistor that can be used in analog circuits and digital circuits. A typical MOSFET device includes a gate, a source, and a drain. The source and drain are close to the gate. The very bottom region is also formed with a lightly doped region (LDD region). Due to the advantages of low manufacturing cost, small use area, and high integration, it is widely used in large-scale integrated circuits (Large-Scale Integrated Circuits, LSI) or ultra-large It is widely used in the field of integrated circuits (Very Large-Scale Integrated Circuits, VLSI). [0003] With the increasing progress of the manufacturing process of semiconductor integrated circuits, in the past few decades, in order to obtain better circuit...

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Problems solved by technology

[0006] MOSFET devices with smaller size can be prepared by prior art methods, and MOSFET size reduction can bring many benefits, but it also causes many negative effects. For example, in the preparation process of the above-mentioned MOSFET devices, due to the further reduction of device size, The size of the oxide 106, the polysilicon layer 108 and the silicide 116 in the gate is also necessarily reduced, so that the channel formed between the source / drain ion-doped regions 114 is further reduced, thus resulting in more The stronger and stronger short-channel effect leads to larger and larger leakage, a substantial increase in power consumption, and a decrease in the ability to resist breakdown, making the standby time of electronic products a great challenge

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