| 摘要 |
PURPOSE:To make it possible to implement a saturation type resistor, whose saturation voltage is small, by forming a second electrode from the upper part of a semiconductor layer so that a part of the second layer is overlapped on a first electrode. CONSTITUTION:An N-type conducting layer 12 is formed on a GaAs substrate 11. A first electrode using an AuGe film and an SiO2 film are formed in a self-aligned laminated manner. Thereafter, an Si3N4 film 15 is deposited on the entire surface as a second insulating film by a plasma CVD method. Then the Si3N4 film 15 is etched by a reactive ion etching method. The film 15 is made to remain only on the side wall of the first electrode 13. A second electrode 16 using an AuGe film is formed form the part on the N-type conducting layer 12 as a second ohmic electrode material layer also by a lift-off method so that a part of the layer 16 is overlapped on the first electrode 13. In order that the ohmic characteristics of the first and second electrodes 13 and 16, which are formed in this way, are made excellent, heat treatment is carried out for one minute at 420 deg.C as a final process.
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