| 摘要 |
PURPOSE:To avoid the deterioration of Schottky characteristic by a method wherein an N<+> region formed under the side surface of a gate electrode, produced by heat treatment in the ion implanted region in the state that a gate metal is formed on the substrate and coated with a protection film, is isolated from the gate electrode by etching. CONSTITUTION:A gate electrode 5 is formed on a channel region 2, and source and drain regions 6 are formed by selective ion implantation with the mask of a metal 4; then, the metal 4 is removed. The whole is coated with an SiO2 film 7, and annealing to activate the ion implanted region is carried out under an As pressure atmosphere by using it as the protection film. At this time, an N<+> region 8 is formed under the side surface of the gate electrode 5. After removal of the SiO2 film 7, the side surface of the electrode 5 is etched by RIE using SF6 as the etching gas in order to isolate the region 8 under the side surface of the electrode 5 from the electrode 5. The Schottky gate type GaAsFET is obtained by finally forming an ohmic electrode 9 on the N<+> region 6. |
