| 摘要 |
PURPOSE:To enhance reproducibility and mass-productivity of semiconductor device by forming a metal electrode which is resistive to a temperature of 500 deg.C or higher on the specified region of semiconductor layer on a high resistance substrate in such a manner that it establishes the Schottky contact thereto and forming a conductivity type layer on the semiconductor of the same conductivity type by the vapor phase deposition method. CONSTITUTION:The tungsten W is stacked on the n type epitaxial layer 12 of the semi- insulating GaAs 11 and the resist mask 31 is provided, followed by etching thereof. The mask is then removed and the gate electrode 13 is formed. The n-GaAs 32 is thereafter formed by the ordinary halogen method of AlCl3. In the halogen method, a crystal does not grow up on the tungsten W and even if a very little amount of amorphous grows, there is no problem because a resistance is high. When the source and drain 14 and 15 are thereafter formed, a field effect transistor (FET) causing a little influence of surface depletion layer because the GaAs 32 is thick can be obtained and when a growth temperature in the halogen method is lowered for example up to 600 deg.C, the thermal metamorphism of the channel region hardly occurs. A growth temperature can further be lowered by the thermal decomposition method of AsH3 and (CH3)3Ga and the required heat resistant temperature of gate metal is about 500 deg.C and requirement on heat resistivity is alleviated. |
