Formation method for fin type field-effect transistor

Abstract

A formation method for a fin type field-effect transistor is disclosed. The formation method comprises the steps of providing a substrate, wherein a plurality of separated fin parts are formed on the surface of the substrate; forming a separating layer on the surfaces of the side walls and the top parts of the fin parts, wherein the etching speed on the separating layer and the etching speed on the fin parts in an etching process are different; forming an impurity layer on the surface of the separating layer, wherein the impurity layer has atoms with the same material as the fin parts ; the impurity layer is further provided with N type ions or P type ions; performing annealing treatment on the substrate to enable the N type ions or the P type ions in the impurity layer to be diffused into the fin parts through the separating layer to form a doping region in the internal of the fin parts; the impurity layer is converted into an intrinsic layer; taking the separating layer as the etching stop layer and etching off the intrinsic layer; and etching off the separating layer until the top parts and the side wall surfaces of the fin parts are exposed. The concentration uniformity of the formed doping region is improved, the amorphization problem on the fin parts caused by the ion implantation technology is avoided, the completeness of the sizes of the fin parts is kept, and the electrical property of the fin type field-effect transistor is optimized.

Description

technical field [0001] The invention relates to the technology in the field of semiconductor manufacturing, in particular to a method for forming a fin field effect transistor. Background technique [0002] With the continuous development of semiconductor process technology, the development trend of semiconductor process nodes following Moore's Law continues to decrease. In order to adapt to the reduction of process nodes, the channel length of MOSFET field effect transistors has to be continuously shortened. The shortening of the channel length has the advantages of increasing the die density of the chip and increasing the switching speed of the MOSFET field effect tube. [0003] However, as the channel length of the device is shortened, the distance between the source and the drain of the device is also shortened, so that the control ability of the gate to the channel becomes worse, and the gate voltage pinches off (pinchoff) the channel. The difficulty is also increasin...

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Problems solved by technology

[0005] However, the electrical performance of the fin field effect transistor formed by the prior art needs to be improved

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