| 摘要 |
PROBLEM TO BE SOLVED: To restrain diffusion of impurities through an insulative substrate to provide an exceedingly stable semiconductor device. SOLUTION: In a semiconductor device having in order a shield layer 2, a channel region, a semiconductor layer 3 constituting source and drain regions, a first insulating layer 4, which is a gate insulating layer, and a gate electrode 5 on an insulative substrate 1, the layer 2 has a silicon oxide film doped with a group V element. By the group V element, diffusion of impurity ions, such as sodium ions, aluminium ions and the like, being contained in the substrate 1 is prevented. Moreover, preferably, a cap layer is formed closer to the layer 3 than to the silicon oxide film doped with the group V element. |
