SEMICONDUCTOR DEVICE AND MANUFACTURE METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To realize a field effect transistor having a high carrier mobility by making a barrier layer being adjacent to a channel layer to be a multilayer film where an Si1-yGey mixed crystal layer and an Si layer are made to grow alternatively, by providing a doped region (layer) at about middle part thereof and by forming a carrier (electron) supplying layer. SOLUTION: An i-Si layer is used as a channel layer and a multilayer film 218 is provided thereon. The multilayer film 218 is formed by a plurality of layers laminating a lower layer constituted of an Si1-yGey mixed crystal layer (for example, i-Si0.4Ge0.6 layer) 215 and an upper layer constituted of an Si layer (i-Si layer) 216. An Si layer doped with a fifth family element and an Si1-yGey mixed crystal layer (doped layer) 217 are provided at the interval between a predetermined i-Si layer 216 and the i-Si0.4Ge0.6 layer 215. The Si1-yGey mixed crystal layer 217 is constituted of the Si layer doped with for example Sb and the Si0.4Ge0.6 layer. An electron supplying layer (carrier supplying layer) is constituted of the Si layer and the Si1-yGey mixed crystal layer.