| 摘要 |
PURPOSE:To obtain electrodes of good flatness by forming, when forming ohmic electrodes on a GaAs substrate havig an N type conductive layer, them of a laminate of an AuGe layer, an Ni layer and an Au layer, specifying the ratio of thicknesses of the AuGe layer and the Ni layer, and heat treating it. CONSTITUTION:Tow N<+> type layers 2 are formed by ion implanting on the surface layer of a semi-insulating GaAs substrate 1, and a shallow N type layer 3 is formed on the surface which includes the layers 2. Then, the entire surface is coated with an SiO2 film 4, a photoresist film 5 having holes 6 for forming ohmic electrodes are opened, and holes are opened on the region 2. Thereafter, an AuGe layer 7 which contains 4-8wt% of Ge, an Ni layer 8 which contains 0.1-0.2 of thickness ratio to the layer 7, and an Au layer 9 are laminated in the hole, heated at 360-410 deg.C in reduced atmosphere as ohmic electrodes. A laminate of a Ti layer 10, a Pt layer 11 and an Au layer 12 is provided on the layer 3 in the film 4 disposed between the electrodes. |
