| 摘要 |
PURPOSE:To improve the Schottky junction withstand voltage of FET and to enable to perform a large amplitude oscillation operation at high output by a method wherein an Si3N4 film, containing Sn which comes in contact with an Si3N4 film, is coated on the GAAs contacting with the side face of a Schottky junction electrode. CONSTITUTION:An SiO2 film 3 containing Sn is superposed on the n-GaAs layer 2 located on a semiinsulating GaAs substrate, an aperture is provided on said film 3, and an Si3N4 film 4 is covered thereon. An N<+> connection layer 5 is formed by performing a heat treatment diffusing Sn. An aperture is provided on the Si3N4 film 4 by performing an anisotropic dry type etching, and the film 4 is left on the side wall of the film 3. Then, a Schottky junction electrode 6 is formed, the SiO2 film 3 located on the connection layer 5 pinching an electrode 6 is partially removed, and ohmic source and drain electrodes 7 and 8 are attached. If the thickness of the Si3N4 film 3 and the condition of heat treatment are properly selected, the Schottky junction electrode does not come in contact with the GaAs connection layer. According to this constitution, a high output and large amplitude operation can be performed, and an FET with improved Schottky junction withstand voltage can also be obtained. |
