Low temperature ultra-scaled fully self-aligned transistor technology (LOTUS) for SiGe-HBTs

Broadband and wireless communication seem to be a technology battle-ground, with new high performance demands to the applied active and passive devices, and the optimization of the circuit design. Up to now, there are several technologies for low power and low noise or high speed application including advanced silicon bipolar transistor, III-V-HBT, and HEMT/MODFET. In this paper the advantages of SiGe-HBTs are presented and discussed regarding the fabrication in a low-cost mass production technology. For further increasing the performance of the SiGe-HBT, the vertical doping profile and the lateral structure need to be optimized. Utilizing new LQw Temperature Ultra scaled fully Self-aligned (LOTUS) integration concepts a Si heterojunction bipolar device can be achieved featuring high package density, good passivation and long-term stability.