| 摘要 |
PROBLEM TO BE SOLVED: To suppress diffusion of Au and thereby to inhibit that current gain deteriorates suddenly. SOLUTION: A sub-collector layer 2 is formed on a substrate 1, a collector layer 3 is formed on the sub-collector layer 2, a base layer 4 is formed on the collector layer 3, an emitter layer 5 is formed on the base layer 4, an emitter contact layer 6 is formed on the emitter layer 5, a metallization layer 7 for contact consisting of Ti is formed on the emitter contact layer 6, a barrier metal layer 8 for Au diffusion prevention consisting of W is formed on the metallization layer 7 for contact, a low resistance metal layer 9 consisting of Ti/Pt/Au/Pt/Ti is formed on the barrier metal layer 8, and a silicon nitride film 10 covering a side surface of an emitter electrode, which comprises of the emitter layer 5, the emitter contact layer 6, the metallization layer 7 for contact, the barrier metal layer 8, and the low resistance metal layer 9, is formed. COPYRIGHT: (C)2009,JPO&INPIT
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