Aspects of the present invention relate to a method for manufacturing a high-performance and low-power field effect transistor (FET) element of which surface roughness scattering is minimized or removed, comprising: a first step of etching a strained silicon substrate into a pin structure; a second step of stacking undoped SiGe thereon; a third step of etching the undoped SiGe; a fourth step of etching after performing lithography; a fifth step of stacking doped SiGe thereon; a sixth step of etching the doped SiGe after performing lithography; and a step of forming a transistor element by sequentially stacking an oxide and a gate metal on the doped SiGe and there is an effect of enabling the implementation of a Fin HEMT capable of having all of good channel controllability and a high on-current, which are advantages of a FinFET, and high electron mobility, which is an advantage of an HEMT.