| 摘要 |
PURPOSE:To decrease a source resistance and to improve electrical characteristics of an element, by performing ion implantation with a gate electrode used as a mask so that a n-type region is formed and forming a high- concentration n-type GaAs layer ranging from the part below an ohmic electrode to the vicinity of the gate electrode. CONSTITUTION:A n-type AlGaAs layer 3 is formed on a GaAs layer 2 which is formed on a semi-insulating GaAs substrate 1. Next, a gate electrode 4 comprising a high-melting-point metallic layer is formed on this n-type AlGaAs layer 3. while the gate electrode 4 is used as a mask, an element 5 acting as a donor in the GaAs layer 2 and the AlGaAs layer 3 is ion-implanted, and annealing processing is performed to form a channel region under the gate electrode 4 and to form n-type regions 6 on both sides of this channel region. Next, an insulating film 7 coating the n-type AlGaAs layer 3 and the gate electrode 4 is etched to remain on the sides of the gate electrode 4. While the gate electrode 4 and the insulating film 7 are used as masks, epitaxial growth of a high-concentration n-type GaAs layer 8 is selectively performed on the n-type AlGaAs layer 3. Thus, a field-effect transistor having a hetero junction is formed, moreover, by sticking ohmic electrodes 9 on the surface. |
