| 摘要 |
PURPOSE:To obtain the FET suitable for the high frequency operation by not forming the source, drain, and gate regions directly in an epitaxial layer which is grown on a semiconductor substrate; but forming them in the island regions provided in the epitaxial layer; in preparing the J-FET. CONSTITUTION:An N type layer 41 is grown on a P<+> type Si substrate 30 by a pressure reduced epitaxial method in order to decrease the autodoping, and the surface is covered by an oxide film 42 by the CVD method. Holes 43 and 44 are provided, P type regions 45 and 46 reaching the substrate 30 are diffused and formed, and the layer 41 is separated. Then, holes are perforated in a layer 47 which is formed with the film 42 being included at the same time, and a shallow N type island region 34 is formed in the separated layer 41 by the ion implantation. Thereafter, the film 47 is transformed into a film 50, windows are provided, and P type gate regions 12, 14, and 16 are diffused and formed in the region 34. Windows are provided in a film 51 which is formed at the same time, and N<+> type source regions 11 and 15 and drain regions 13 and 17 which are located between the gate regions are diffused and formed. Thus, the mutual conductance is increased. |
