| 摘要 |
PURPOSE:To distribute an impurity uniformly, and to eliminate the variance of threshold voltage due to a crystal defect by applying a protective film on a semi-insulating GaAs substrate, implanting O2 ions or H2 ions having no adverse effect on a semiconductor device afterward through the protective film, implanting required impurity ions and thermally treating the whole as the protective film is left as it is. CONSTITUTION:A protective film of SiO2, Si3N4, AlN, etc. is applied on a semi- insulating GaAs substrate through a sputtering method or a thermal decomposition method, and H<+>: proton.ions are implanted through the protective film while the quantity of a dose is brought to approximately 10<14>/cm<2>. Si<+> ions are implanted through said protective film while the quantity of a dose is brought to approximately 2X10<12>/cm<2>, and the whole is thermally treated for approximately twenty min at approximately 850 deg.C as the protective film is left as it is. Accordingly, Si impurity is distributed extending over the whole operating region, and the variance of threshold voltage is eliminated while the resistance value of a resistance layer is equalized. |
