HETEROJUNCTION BIPOLAR TRANSISTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME

摘要

PURPOSE: A heterojunction bipolar transistor device and a method for manufacturing the same are provided to reduce a parasitic capacitance by using a process for forming an oxide layer. CONSTITUTION: A GaAs layer(11) of a high density for a collector contact is formed on a GaAs substrate(10). An Al(x)Ga(1-x)As layer(20) of the high density is formed on the GaAs layer(11). A GaAs layer(13) of a low density is formed on the Al(x)Ga(1-x)As layer(20). A GaAs base layer(14) of p-type high density is formed on the GaAs layer(13). An AlGaAs or an InGaP emitter layer(16) is formed on the GaAs base layer(14). A GaAs or an InGaAs layer(17) for reducing an emitter resistance is formed on the AlGaAs or the InGaP emitter layer(16). An AlGaAs oxide layer(19) is formed at an edge portion of the AlGaAs layer.