MIS-integrated semiconductor device

Claim 1

A MIS integrated semiconductor device comprising: one chip having thereon a first MIS transistor comprising an insulating gated field effect MIS transistor having a first channel region of one conduction type comprising a portion of a first well of the one conduction type formed in a substrate crystal of an opposite conduction type to said one conduction type, first source and drain regions of said opposite conduction type formed in said first well, a first gate insulating film on said first channel region and a first gate electrode on said first gate insulating film, and also on the one chip a second MIS transistor comprising a MIS static induction transitor having a second channel region of said one conduction type with an impurity concentration lower than that of said first channel region, second source and drain regions of said opposite conduction type formed in said second channel region in spaced-apart relation along the length direction thereof, a second gate insulating film on said second channel region, and a second gate electrode on said second gate insulating film and having a narrower width in said length direction than the length of said second channel region between said second source and drain regions, wherein said second channel region comprises a solid-phase epitaxial layer grown on a second well of said one conduction type formed simultaneously with said first well or on an elongated portion of said first well and has an impurity concentration determined by the impurity diffusion from said second well or said elongated portion of said first well.