| 摘要 |
PURPOSE:To improve the emitter injection efficiency by providing a quantum well to a base layer to form a quantum well structure. CONSTITUTION:An N<+> type Si-doped GaAs buffer layer 12, a collector layer 13, a Be-modulation-doped quantum well base layer 14, an emitter layer 15, and an n<+> type Si-doped GaAs contact layer 16 are sequentially grown on a semi-insulating GaAs substrate 11 by a molecular beam epitaxy method. The layer 14 is formed by alternately laminating 4 undoped GaAs layers 21 and 3 P<+> type AlGaAs layers 22, thereby forming a quantum well structure. Then, Zn is diffused only at the position for forming a base electrode with a patterned Si3N4 film as a mask. Then mesa etching is conducted as for as the layer 12, Au/Ge/Ni are deposited in all the collector, base and emitter regions to be alloyed. Thereafter, a region between the base and the emitter is recess-etched. Holes 28 are enclosed in a two-dimensional manner in the quantum well to prevent them from being injected to the emitter 29 side, thereby improving the emitter injection efficiency. |
