| 摘要 |
PURPOSE:To readily obtain two-type FETs on the same substrate by forming, by epitaxial growth, a plurality of operating layers of normally OFF FET, and altering by impurity ion implantation some of them into the operating layers of normally ON FET. CONSTITUTION:A buffer layer 12 and the operating layers 13 of normally OFF MES-FET are laminated and epitaxially grown on a semi-insulating substrate 11, and the operating layer 13 except normally OFF and ON FET forming regions is removed. Then, an insulating film 17 made of SiO2, Al2O3 is covered on the overall surface which includes the remaining layers 13, the film 17 of the part is removed corresponding to the layers 13 for the normally ON FET, and the operating region 18 of the normally ON FET is formed by impurity ion implantation. In this manner, the normally OFF type operating layers are first formed, part of them is altered to normally ON type operating layers, thereby readily obtaining FETs of two types on the same substrate. |
