Fin transistor and making method thereof

Abstract

The invention discloses a fin transistor comprising a silicon fin body with an initial first width. The bottom of the silicon fin body is isolated by a first insulation layer. A source region and a drain region are formed in the silicon fin body. After pseudo grid removing and before metal gate structure forming, isotropic etching type thinning is carried out on the silicon fin body exposed by anarea with the pseudo grid removed; and a germanium-silicon epitaxial layer coats the lateral surface and the top surface of the thinned silicon fin body by epitaxial growth, wherein the germanium concentration of the germanium-silicon epitaxial layer is in gradient distribution. The metal gate structure covers the top surface and the lateral surface of the germanium-silicon epitaxial layer and thegermanium-silicon epitaxial layer forms a channel region. In addition, the invention also discloses a making method of a fine transistor. Therefore, the channel region is formed by using a germaniumsilicon material without the need to use the silicon germanium fin body separately, so that the conductive performance of the device is improved; and no SRB layer is need, so that the cost is loweredand the process is simplified.

Description

technical field [0001] The invention relates to the field of semiconductor integrated circuit manufacturing, in particular to a fin transistor (FinFET transistor). The invention also relates to a method for manufacturing a fin transistor. Background technique [0002] With the continuous development of semiconductor technology, the process flow after the process node reaches 10nm may introduce silicon germanium (SiGe) x Ge 1-x ) or pure germanium (pure Ge) as the channel region (channel) material. The main reason is that the electron mobility and hole mobility of germanium are 2.5 times and 4 times that of silicon (Si), respectively, which can greatly increase the driving current under the condition of reducing the operating voltage. [0003] However, germanium (Ge) has poor thermal conductivity (thermal conductivity), that is, low thermal conductivity, poor interface contact with high dielectric constant (HK) materials (poor HK interface), and high junction leakage (junc...

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Problems solved by technology

[0003] However, germanium (Ge) has poor thermal conductivity (thermal conductivity), that is, low thermal conductivity, poor interface contact with high dielectric constant (HK) materials (poor HK interface), and high junction leakage (junction leakage), etc. Disadvantages; In addition, it also has the disadvantage that germanium oxide (GeO, GeO2) is not a stable state (stable state)

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