| 摘要 |
PROBLEM TO BE SOLVED: To simultaneously achieve a high current gain, fast operation and a high voltage resistance property in an InP-based HBT.SOLUTION: A heterojunction bipolar transistor comprises: a first protection layer 111 formed from silicon nitride by covering a side surface of an emitter contact layer 108 and a top face of an emitter layer 107 outside of a region where the emitter contact layer 108 is formed; a second protection layer 113 formed from benzocyclobutene (BCB) by covering an outer side surface of the first protection layer 111, a top face of a base layer 106 excluding a region where the emitter layer 107 is formed and a region where a base electrode 110 is formed; and, in addition, a third protection layer 114 formed from silicon nitride by covering an outer side surface of the second protection layer 113, side surfaces of a first collector layer 103, a second collector layer 104, a third collector layer 105 and the base layer 106 and a bottom face of eaves of the second collector layer 104 closer to a substrate 101. |
