| 摘要 |
PURPOSE:To conduct heat treatment at a high temperature easily for forming ohmic electrodes by growing a large number of semiconductor layers into a plurality of recessed sections shaped to an insulating substrate, each forming semiconductor-layer electrodes required onto the surfaces of the semiconductor layers grown into the recessed sections and shaping severally independent transistor element structure. CONSTITUTION:One substrate surface of a GaAs insulating substrate 1 is mesa- etched to form a recessed section 2 with a stepped section 2a. An silicon nitride film SiN4 is shaped onto the surface of the substrate 1 except the recessed section 2 as an insulating film 20. An N<+>-GaAs layer 3, an N-GaAs collector layer 4, an N-AlGaAs layer 5 and a P<+>-GaAs layer 6 are crystal-grown in succession while using the insulating film 20 as a mask. A resist film 22 is shaped so as to leave the section of the P<+>-GaAs layer 6 as a section left as a control-electrode forming region 21 and the section of the N-AlGaAs layer 5 on the lower side of the section of the layer 6, and these layers 6 and 5 are etched. The AlGaAs layer 5 except the base-electrode leading-out section 21 is etched by employing an etching liquid, which can each the AlGaAs layer 5 but cannot each the GaAs layer 6. |
