| 摘要 |
PROBLEM TO BE SOLVED: To suppress the deterioration of transistor performance when reducing a collector concentration in order to improve the breakdown voltage of a bipolar transistor. SOLUTION: The bipolar transistor 100 includes a heterojunction intrinsic base layer 50 epitaxially grown on a collector layer 3. The intrinsic base layer 50 is disposed on the collector layer 3 surrounded by an isolation layer 4, and an N-type impurity layer 30 is formed in a surface portion of the collector layer 3. The impurity concentration of the N-type impurity layer 30 is higher than the impurity concentration of the collector layer 3 under the N-type impurity layer 30. Between the N-type impurity layer 30 and the intrinsic base layer 50, an epitaxially grown layer is formed, where the epitaxially grown layer is lower in impurity concentration than the N-type impurity layer 30 and the intrinsic base layer 50. COPYRIGHT: (C)2011,JPO&INPIT
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