| 摘要 |
PURPOSE:To omit a special material for forming a resistor, by using a semiconductor, which is to become the base or the collector of a transistor as a resistor for a semiconductor device, in which a heterojunction transistor is used as an element. CONSTITUTION:On a semi-insulating substrate 1, an n<+> type GaAs layer 2 is epitaxially grown. Then, a n<-> type GaAs layer 5, a p<+> type GaAs layer 6 and an n<-> type GaAlAs layer 7 are epitaxially grown by an MBE method and the like. The impurity concentrations of the layers are controlled at the desired values. The n<-> type GaAlAs layer 7 (emitter layer) is completely removed from a resistor forming region 10, and a resistor and wirings 21 and 22 are directly connected. Then, mesa etching is performed and a mesa hole part 14 is formed. The n<+> type GaAs layer 2, which is to becomes a collector C, is exposed. Thereafter, p<+> and n<+> impurities for contacting a base B and an emitter E are diffused. Then an AuGe electrode or wirings 18-21 are patterned. The resistance value can be freely selected by appropriately selecting the concentration and the film thickness. |
