Method for fabricating semiconductor device with ultra-shallow super-steep-retrograde epi-channel by boron-fluoride compound doping

The present invention relates to a method for fabricating a semiconductor device and, more particularly, to a method for fabricating a semiconductor device with an ultra-shallow epi-channel of which the channel length is 100 nm or less. This invention relates to a method for fabricating a semiconductor device with the epi-channel structure, which is adapted to overcome an available energy limitation and to improve the productivity by providing the method of SSR epi Channel doping by boron-fluoride compound ion implantation without using ultra low energy ion implantation and a method for fabricating the semiconductive device with epi-channel structure adapted to prevent the crystal defects caused by the epitaxial growth on ion bombarded and fluorinated channel doping layer. The method for forming the epi-channel of a semiconductor device includes the steps of: forming a channel doping layer below a surface of a semiconductive substrate by implanting boron-fluoride compound ions containing boron; performing an annealing process to remove fluorine ions, injected during above ion implantation, within the channel doping layer; performing the surface treatment process to remove the native oxide layer formed on the surface of the channel doping layer and simultaneously to remove remaining fluorine ions within the channel doping layer; and growing epitaxial layer on the channel doping layer using the selective epitaxial growth method.