Manufacturing method for MOS transistor

Abstract

The invention provides a manufacturing method for an MOS transistor. On one hand, charge mobility is increased by germanium-doped silicon epitaxy to inhibit hot carrier's effect; on the other hand, by an inner wall with a lower top, radial diffusion is inhibited in lightly doped source / drain (LDD) region after ion implantation and the depth of the lightly doped source / drain (LDD) extension region is controlled, which allows ultra-shallow junction shallower. Therefore longer effective channel is obtained, HCI effect is effectively inhibited, SCE and RSCE effects are significantly improved and breakdown effect and electric leakage caused by breakdown effect brought by shrunk device size are reduced, enabling the production of even shallower source / drain region junction in the ultra-shallow junction technology.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a method for manufacturing a MOS transistor. Background technique [0002] As the size of MOSFET devices continues to shrink, especially when entering the node of 65 nanometers and below, MOSFET devices highlight various adverse physical effects due to the extremely short channel, especially the short channel effect (SCE), which makes the device performance and reliability Sexual degradation, which limits the further reduction of feature size. Currently, an ultra-shallow junction structure (a doped junction with a junction depth below 100 nm, USJ) is usually used to improve the short-channel effect of the device. [0003] In the prior art, the low-energy lightly doped source / drain region (LDD) ion implantation is usually performed sequentially with the first ion and the second ion to form a lightly doped source / drain extension region (such as figure 1 101) to achieve ...

AI Technical Summary

Problems solved by technology

Among them, the second ion LDD implantation is usually to eliminate the short channel effect caused by the first ion LDD implantation, but the second ion LDD implantation is prone to produce transient enhanced diffusion effect (TED), resulting in degradation of short channel device characteristics and junction leakage In addition, the hot carrier injection effect (HCI) generated by the implanted first and second ions in the annealing process makes the depth of the formed ultra-shallow junction unable to be effectively reduced, and it is difficult to achieve the SCE of the device. (short channel effect) control and lower junction leakage performance

Images