Transistors and methods of forming them

Abstract

A transistor and its forming method, the forming method comprising: providing a substrate; forming a gate structure on the substrate; forming grooves in the substrate on both sides of the gate structure; forming a first An epitaxial layer, the first epitaxial layer has doping ions; a mask layer is formed on the sidewalls on both sides of the gate structure, the mask layer is located on the first epitaxial layer and exposes a part of the first epitaxial layer An epitaxial layer surface; a second epitaxial layer is formed on the first epitaxial layer exposed by the mask layer, the second epitaxial layer has the same type of doping ions as the first epitaxial layer, and the first epitaxial layer has the same type of doping ions as the first epitaxial layer. Layers form source and drain doped regions. The forming method of the transistor provided by the present invention can reduce the parasitic capacitance between the source-drain doped region and the gate structure, thereby reducing the occurrence probability of signal delay phenomenon between semiconductor devices, and further improving the performance of the transistor.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a transistor and a forming method thereof. Background technique [0002] With the continuous development of semiconductor technology, carrier mobility enhancement technology has been widely studied and applied. Improving the carrier mobility in the channel region can increase the driving current of MOS devices and improve the performance of the devices. [0003] In the existing manufacturing process of semiconductor devices, since stress can change the energy gap and carrier mobility of silicon materials, it has become an increasingly common means to improve the performance of MOS transistors through stress. Specifically, by properly controlling the stress, the mobility of carriers (electrons in NMOS transistors and holes in PMOS transistors) can be increased, thereby increasing the driving current, thereby greatly improving the performance of MOS transistors. [0004]...

AI Technical Summary

Problems solved by technology

[0005] The introduction of embedded silicon germanium technology or embedded silicon carbon technology can improve the carrier mobility of semiconductor devices to a certain extent, but in practical applications, it is found that the introduction of embedded silicon germanium technology or embedded silicon carbon technology can easily lead to High parasitic capacitance around transistor gate structures, affecting transistor performance

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