From Semiconductor Today:
Hong Kong University of Science and Technology (HKUST) has been advancing technologies for direct growth of indium phosphide (InP) on silicon (Si) substrate with a view to monolithic integration of optoelectronics on a low-cost platform.
In particular, professor Kei May Lau’s group at HKUST claims the first indium gallium arsenide/indium aluminium gallium arsenide (InGaAs/InAlGaAs multi-quantum-well (MQW) lasers directly grown on on-axis V-grooved (001) Si by metal-organic chemical vapor deposition (MOCVD) [Si Zhu et al, Optics Express, vol26, p14514, 2018]. Miscut silicon substrates are often used to grow III-V materials to avoid defects such as anti-phase boundaries.
Integration of lasers with on-axis silicon is desired for the interconnection of photonic integrated circuits and optical-fiber large-scale networking with the efficient, complex complementary metal-oxide-semiconductor (CMOS) electronics that powers today’s communications technologies. Monolithic integration, it is hoped, will reduce the costs arising from additional processing needed for wafer bonding, and also allow the use of larger-diameter substrates for economies of scale.
The V-groove Si was created by etching with potassium hydroxide solution through a silicon dioxide (SiO2) mask. The parallel stripes were made with a 130nm pitch. The silicon surface was prepared for MOCVD with 800°C thermal desorption of native oxide.