Group IV Alloys for Advanced Nano‐ and Optoelectronic Applications

Mainstream semiconductor technology builds on elements of group IV within the periodic table. Crystalline silicon remains the principal base material, whereas germanium and carbon have entered the mainstream in the embedded source/drain technology, as well as in heterojunction bipolar transistors (HBTs) used in BiCMOS technology. Recently, it has been shown that alloying Ge with Sn enables the fabrication of fundamental direct bandgap group IV semiconductors, as well as optically pumped GeSn lasers grown on Si. This achievement pave the route toward efficient and monolithically integrated group IV light emitters, that is, lasers, for electronic‐photonic integrated circuits (EPICs) that could solve the emerging power consumption crisis in complementary metal‐oxide semiconductor (CMOS) technology by enabling optical on‐chip and chip‐to‐chip data transfer. The large parasitic capacitances introduced by various layers of copper (Cu) interconnects demand high transistor I_ON currents, which could be reduced if some of the Cu lines are replaced by optical interconnects.