Anti-punch-through doping method of FinFET structure

Abstract

The invention provides an anti-punch-through doping method of a FinFET structure. The method comprises the following steps that: a plurality of laminated layers comprising Fin structures, buffer layers and hard mask layers are formed on a silicon substrate, the laminated layers are divided into a first structure and a second structure; first side walls are formed on the side walls of the laminated layers; an organic distribution layer is deposited; etching is performed to expose the side wall parts of a fin structure; a part of the fin structure is wrapped; second side walls are formed to expose a fin structure side wall part in direct contact with the organic distribution layer; the first structure, the second structure and the silicon substrate are covered with a BSG layer; the BSG layer on the second structure is removed; the second structure is covered with a PSG layer; annealing is performed to laterally diffuse silicon in the BSG layer on the side wall of the fin structure in the first structure and phosphorus in the PSG layer on the side wall of the fin structure in the second structure into the fin structure; silicon in the BSG layer on the silicon substrate and phosphorus in the PSG layer on the silicon substrate are diffused into the silicon substrate; an oxide layer is covered, and etching is performed to expose the hard mask layers on the first structure and the second structure; and the oxide layer, the BSG layer and the PSG layer are etched, and the upper end of the diffused part in the fin structure is exposed.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to an anti-puncture doping method of a FinFET structure. Background technique [0002] With the continuous expansion of MOS scale, FinFET (fin transistor) devices have become a further technical expansion of CMOS. The main advantage of the FinFET device structure is its superior electrostatic integrity, which is largely dependent on the channel morphology. Figure 1a Shown as a schematic diagram of a FinFET structure in the prior art, where the FIN (fin portion) is wrapped by a metal gate (MG) below the depth H of the top of the FIN, and the lower part of the FIN has a greater risk of penetration, especially when the source and drain The deeper the channel, the higher the doping concentration. [0003] At present, after APT (anti-punch through) doping implantation, there is a problem of damage. The top doping concentration of FIN is extremely low, and the mobility of carriers...

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Problems solved by technology

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide an anti-puncture doping method for the FinFET structure, which is used to solve the problem that in the prior art, in the manufacturing process of the FinFET structure, the mid-high of the channel at the bottom of the FIN cannot be satisfied at the same time. The issue of mobility and FIN bottom anti-penetration risk

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