Ion injection method of bag-shaped injection region and manufacture method of MOS (Metal Oxide Semiconductor) transistor

Abstract

The invention relates to an ion injection method of a bag-shaped injection region for forming an MOS (Metal Oxide Semiconductor) transistor and a manufacture method of the MOS transistor, wherein the ion injection method of a bag-shaped injection region for forming the MOS transistor comprises the following steps of: rotating a wafer for a first angle by using a straight line which runs through the center of the wager and is vertical to the wafer as a rotating shaft; injecting source/drain region ions for forming the bag-shaped injection region; rotating the wafer for a second angle by using the straight line as a rotating shaft, wherein the rotating direction of the first angle is the same as that of the second angle; and by keeping the ion injection direction unchanged, repeatedly carrying out the steps of injecting the source-drain region ion for forming the bag-shaped injection area and rotating the wafer for the second angle until the wafer returns to the state after the wafer isrotated for the first angle. Compared with the prior art, the invention can control the junction capacitance of the MOS transistor.

Description

technical field [0001] The invention relates to the manufacturing field of semiconductor devices, in particular to an ion implantation method for forming a pocket-shaped implantation region of a MOS transistor and a manufacturing method of the MOS transistor. Background technique [0002] Metal-oxide-semiconductor (MOS) transistors are the main driving force as semiconductor devices move toward high density and small size. The driving current and hot carrier injection are the two most important parameters in the design of MOS transistors. Traditional design achieves expected performance by controlling gate oxide, channel region, well region, source / drain extension doping shape, pocket implant region, source / drain implant shape and thermal budget, etc. . [0003] As the channel length of MOS devices becomes shorter, the source / drain depletion regions are too close to each other, which will lead to undesired punch through current and short channel effect. Therefore, those s...

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Problems solved by technology

[0004] However, the doping ion species of the lightly doped drain (LDD) structure is different from the conductivity type of the semiconductor substrate or the doped well forming the MOSFET region, while the conductivity type of the pocket-shaped implanted region is different from that of the semiconductor substrate or The conductivity type of the doped well forming the MOSFET region is the same, therefore, a PN junction will be generated between the source / drain extension region and the pocket implant region, and the dopant ion density in the lightly doped drain structure and the pocket implant region are relatively high, resulting in junction leakage

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