| 摘要 |
PURPOSE:To activate the implanted ions on the titled semiconductor device in a high efficiency by performing a cap annealing by a method wherein, after ions are implanted on a semiconductor substrate, a heat treatment is performed in two stages, namely, at a low temperature for a long period and at a high temperature for a short period. CONSTITUTION:After <30>Si<+> ions are implanted for the purpose of forming an n type active layer 2 on the surface of a semiconductor GaAs substrate 1, a W3Si3 layer 3 to be turned to a heat-resisting gate is formed by performing a sputtering method. The layer 3 is brought into the desired gate length by performing a plasma etching using SF6 gas, and after an SiO2 film 4 is grown in vapor phase, the side wall of a W5Si3 gate 4 is coated by SiO2 films 5 and 6 by performing a reactive ion etching using CF4 gas. n<+> type layers 7 and 8 are obtained by implanting <28>Si<+> ions. After a heat treatment is performed at 400 deg.C in a hydrogenous atmosphere for 48hr, and the layers 2, 7 and 8 are activated by performing an annealing at 800 deg.C for 20min. By performing the above-mentioned primary annealing, the generation of microcracks 9 and 10 on the gate end face can be prevented. Then, after removal of a protective layer 11, Au-Ge/Ni layers 12 and 13, a Ti-Au source electrode 14 and a drain electrode 15 are formed, and a GaAs FET is obtained. |
