| 摘要 |
PURPOSE:To obtain a transistor having good high frequency characteristics by forming a bipolar transistor with a GaAs crystal, forming it in a forward mesa shape, burying the mesa with a high resistance layer, and forming a region separating from the emitter contact by ion implantation but contacting only with the base contact. CONSTITUTION:An N<+> type GaAs contact layer 22, a high purity N type GaAs collector layer 23, a P<+> type GaAs base layer 24, an N<-> type AlGaAs emitter layer 25, a high density GaAs contact layer 26 are laminated, epitaxially grown on an N type GaAs substrate 21 to form a bipolar transistor. Then, the transis tor is formed in a forward mesa structure while a mesa is intruded into the layer 22, buried with a high resistance epitaxial layer 27, acceptor ions are implanted to form a P<+> type layer 28 which does not pass the layer 27, is sepa rated from the layer 26 and contacted only with the end of the layer 24. Then, a base electrode 30 is coated on the layer 28, an emitter electrode 29 is coated on the layer 26, and a collector electrode 31 is coated on the back surface of the substrate 21. Thus, a parasitic capacity is reduced. |
