| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To further improve off-breakdown voltage without sacrificing high-frequency characteristics in an InP-based HBT having a base layer composed of a GaAsSb-based compound semiconductor. <P>SOLUTION: A heterojunction bipolar transistor comprises: a first collector layer 102 formed above a substrate 101 composed of InP; a second collector layer 103 formed on the first collector layer 102; a base layer 104 formed on the second collector layer 103 and composed of a compound semiconductor containing Ga, As, and Sb; and an emitter layer 105 formed on the base layer 104 and composed of a compound semiconductor containing In and P. The second collector layer 103 has an energy level of a conduction band edge lower than that of the base layer 104 and higher than that of the first collector layer 102, and has an energy level of a valence band edge lower than that of the base layer 104, while contacting the first collector layer 102 and the base layer 104. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
