| 摘要 |
PROBLEM TO BE SOLVED: To provide an epitaxial wafer for a heterojunction bipolar transistor capable of reducing resistance of a sub-collector layer without reducing a current amplification factor and a heterojunction bipolar transistor.SOLUTION: An epitaxial wafer 100 for a heterojunction bipolar transistor includes a sub-collector layer 102, composed of n-type GaAs. The sub-collector layer 102 includes: an n-type impurity of a covalent bond radius smaller than a covalent bond radius of a substitution site; and an n-type impurity of a covalent bond radius larger than the covalent bond radius of the substitution site.SELECTED DRAWING: Figure 1 |
