Ion implantation method for pocket implantation region and method for manufacturing MOS transistor

Abstract

The invention relates to an ion implantation method for forming a pocket-shaped implantation region of a MOS transistor and a manufacturing method of the MOS transistor. Wherein, the ion implantation method for forming the pocket-shaped implantation region of the MOS transistor forms the pocket-shaped implantation region through ion implantation of two multi-step rotations, and the initial angles of the two multi-step rotations are different. Compared with the prior art, the present invention can control the junction capacitance of the MOS transistor and make the threshold voltage Vt of the manufactured MOS transistor vary more smoothly with Id, so the present invention is more conducive to the manufacture of smaller sized MOS transistors.

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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