| 摘要 |
PURPOSE:To operate a transistor at high speed, and to improve an amplification factor by forming a base layer and an emitter layer through a planar doping method. CONSTITUTION:A semi-insulating GaAs substrate 1 is used, and a non-doped buffer layer 2 is grown on the substrate 1. A collector-contact layer 3 is grown while Si is doped. A collector layer 4 is grown. There layers are grown by using a MBE method. The projection of Ga is stopped by the device, Be as a p-type impurity is projected in an atmosphere consisting of only As, and only one layer is doped (called planar doping). Be is stopped, Ga is projected, and a non-doped GaAs layer in 20Angstrom is grown. The processes are repeated ten times, thus forming a base layer 5. n-type Si is doped in a planar manner by thirty layers at the period of 20Angstrom as an emitter layer 6. Thin base-emitter regions in extremely high concentration are shaped by employing a planar doping method as mentioned above. |
