A FABRICATION METHOD OF ULTRA-THIN FINFET AND THE ULTRA-THIN FINFET FABRICATED BY THIS METHOD.

摘要

The purpose of the present invention is to provide a transistor having improved performance than a conventional FinFET by manufacturing a UTFinFET having an ultra-thin fin (UTFin) whose thickness is thinner than that of a fin which can be manufactured by a conventional FinFET manufacturing process. In order to achieve the purpose, a semiconductor device according to the present invention comprises a step of forming two Si-UTFins which protrude from a substrate and are formed on both sides of a fin made of Si and SiGe layers using an epitaxy method. The UTFin formed in this method replaces the role of a fin of a conventional FinFET. A UTFin formed using an epitaxy method overcomes a thickness limit which a fin formed by lithography has, and can have a thickness of less than 10 nm. [Reference numerals] (AA) Step of preparing a Si substrate; (BB) Step of forming a SiGe layer; (CC) Step of placing a hard mask on a Si-Fin area by patterning the hard mask on the SiGe layer; (DD) Step of forming a Si-Fin through an etching process; (EE) Step of growing a Si layer on both sides of the Si-Fin and both sides of the SiGe layer in an epitaxy method; (FF) Step of forming a first impurity resign by firstly doping an impurity into a Si-UTFin; (GG) Step of etching the hard mask; (HH) Step of firstly depositing oxide in a region etched while forming the Si-Fin, making an oxide surface even, and etching the oxide; (II) Step of forming two Si-UTFins on both sides of the Si-Fin and both sides of the SiGe layer; (JJ) Step of forming an air filled structure in a space formed by a secondly deposited oxide, the lower part of the Si-UTFin, and the Si-Fin by secondly depositing oxide onto inner walls, outer walls, top between two Si-UTFins under poor step coverage conditions and making an oxide surface even; (KK) Step of depositing a gate stack electrode; (LL) Step of forming source and drain regions which are second and third impurity regions respectively by secondly and thirdly doping on left and right sides of the Si-UTFin