A method for fabricating a semiconductor transistor is disclosed. A substrate of a first conductivity type is provided. An ion well of a second conductivity type is formed in the substrate. An epitaxial channel layer of the first conductivity type is grown from the main surface of the substrate. A gate dielectric layer is formed on the epitaxial channel layer. A gate is formed on the gate dielectric layer. A source region and a drain region are then formed in the substrate. The source region and the drain region have the first conductivity type.