| 摘要 |
PURPOSE:To enable heat treatment for compound semiconductor by usual electric oven by using complex film of Si3N4 and SiO2 as a protective film for heat treatment. CONSTITUTION:In GaAs substrate, an Si implantation layer is selectively arranged and SiO2 film is evaporated on surface of the substrate by vacuum evaporation and Si3N4 film is laminated by CVD method. After that, annealing is done in N2 at 800 deg.C followed by removing Si3N4/SiO2 film by buffer solution of hydrofluoric acid and then ohmic electrode is applied. By this constitution, there is no crack produced in Si3N4/SiO2 film after annealing and surface of the crystal after the removal maintains its mirror surface before annealing and variability of characteristics is reduced. This constitution enables heat treatment with use of usual electric oven being used for, for example, heat oxidation of Si element, resulting in mass production. In addition, heat treatment in V group or VIgroup gas is unnecessary thereby improving safety and sanitation as well as the characteristics of the device. |
