| 摘要 |
PURPOSE:To achieve lift-off easily and avoid creation of a recess in a GaAs substrate even after a heat treatment process by a method wherein a novolak system photoresist film is formed on an organic silane film formed on the GaAs substrate and, after patterning, metal is deposited on the exposed GaAs substrate and the novolak photoresist film left after patterning and the organic silane film is removed. CONSTITUTION:A GaAs substrate 1 is coated with an organic silane film 2 with a thickness of 100-500 Angstrom applied by a spinner method and a novolak photoresist film 3 with a thickness of about 8000 Angstrom is formed on the organic silane film 2 by coating. After the organic silane film 2 and the novolak photoresist film 3 are baked and a required pattern is formed, the exposed surface of the GaAs substrate 1 is cleaned by an O2 plasma. Then metal 4 composed of Au/Ni/Au-Ge is deposited over the whole surface. Then the metal 4 on the novolak photoresist film 3 is removed. After organic washing and so forth, the metal is alloyed. The organic silane film 4 which is dissolved and decomposed by solvent easily is provided between the GaAs substrate 1 and the novolak photoresist film 3. Therefore, the organic silane film 4 relieves the adhesiveness between the GaAs substrate 1 and the novolak photoresist film 3 so that easy lift-off can be provided. Even after alloying, creation of a recess near the end of the metal on the GaAs substrate can be avoided.
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