BiHEMT device having a stacked separating layer

摘要

A high electron mobility bipolar transistor including a substrate, a pseudomorphic high electron mobility transistor (pHEMT) sub structure, a sub collector/separating layer and a heterojunction bipolar transistor (HBT) sub structure sequentially stacked from bottom to top is disclosed. The sub collector/separating layer and the pHEMT sub structure are combined to form a pHEMT, and the sub collector/separating layer and the HBT sub structure are combined to form an HBT. The carbon concentration in the sub collector/separating layer is within 5×1017 cm−3 and 1×1020 cm−3, and/or the oxygen concentration within 5×1018 cm−3 and 1×1020 cm−3. The lattice during the process of epitaxy growth is stabilized and it is possible to prevent the dopants, the elements, the vacancies or the defects from diffusing into the neighboring layers, thereby improving the problem of mobility degradation and resistance increase, and sustaining the stability of the manufacturing process.

主权项

1. A BiHEMT, comprising:
a substrate formed with gallium arsenide; a pseudomorphic high electron mobility transistor (pHEMT) substructure formed on the substrate; a stacked separating layer comprising a cap layer, a separating layer and a sub-collector layer sequentially stacked from bottom to top, at least one of the cap layer, the separating layer and the sub-collector layer having a carbon concentration within 5×1017 cm−3 and 1×1020 cm−3; and a heterojunction bipolar transistor (HBT) substructure formed on the stacked separating layer, wherein the cap layer and the pHEMT substructure are combined to form a pHEMT, the sub-collector layer and the HBT substructure are combined to form an HBT such that the pHEMT and the HBT are joined together by the separating layer, and each of the cap layer and the sub-collector layer has a thickness of 0.5˜1000 nm.