| 摘要 |
PURPOSE:To eliminate the occurrence of a damage on the surface of a substrate in a semiconductor device by laminating an oxide film and a nitride film on the surface of the substrate when forming selectively the nittide film on the surface of a semiconductor substrate, retaining necessary nitride film, thereafter etching the oxide film using a mask having larger size than the nitride film. CONSTITUTION:A buffer layer 12 is coated on a semiconductor substrate 11 of GaAs or the like, a mesa portion 14 is formed thereon, an operation layer 13 is formed on the top of the mesa portion to form a semiconductor wafer 10. When a desired Si3N4 film 22 isolated from the layer 13 is formed then on wafer 10, an SiO2 film 21 and an Si3N4 film 22 are laminated on the entire surface of the wafer 10, are grown in vapor phase, are plasma etched with a mask of a photoresist film, and the film 22 is retained only on bonding pad portion 50. Thereafter, the film 21 is removed using an etchant with a mask large than the film 22, and there can be obtained a structure of an SiO2 film and an Si3N4 film extended from the GaAs substrate at the pad 50. |
