Passivation Ledge Fabrication and Its Effect on Performance of Self-Aligned InGaP/GaAs HBT with Variety of Emitter Sizes
钝化边的制作及其对不同尺寸自对准InGaP/GaAs HBT性能的影响

The self-aligned InGaP/GaAs heterojunction bipolar transistors (HBTs) with passivation ledge are fabricated.The performances of the HBTs with and without passivation ledge are compared.The results show that they have the same high-frequency performance both for the devices without passivation ledge and for the devices with passivation ledge.But the improvement of the current gain is different for the devices with different emitter sizes.The devices with smaller size of emitter are more sensitive to the passivation ledge.Moreover,the reliability of all devices with the passivation ledge is improved.