SEMICONDUCTOR WAFER FOR HETEROJUNCTION BIPOLAR TRANSISTOR AND HETEROJUNCTION BIPOLAR TRANSISTOR

摘要

The present invention includes: a semi-insulating substrate; a first layer that is formed on the semi-insulating substrate and functions as a subcollector layer; and a second layer that is formed on the first layer and functions as a collector layer. The first layer is doped with tellurium as an n-type impurity at a concentration of 3.0 x 10¹⁸ cm^-3 to 9.0 x 10¹⁹ cm^-3. A third layer composed of at least an InGaP layer or a GaAs layer is disposed between the first layer and the second layer.