(1) Monolithic photoelectric integration
In recent years, silicon-based photonic devices have developed rapidly, such as optical switches, modulators, micro-ring filters, etc. The design and manufacturing technology of unit devices based on silicon technology has been relatively mature. By rationally designing and organically integrating these photonic devices with traditional CMOS processes, silicon photonic devices can be fabricated on the traditional CMOS process platform at the same time, thereby forming a monolithic integrated optoelectronic system with certain functions. However, the current optoelectronic integration technology still needs to address sub-micron etching technology, process compatibility between photonic devices and electronic devices, thermal and electrical isolation, integration of light sources, optical transmission loss and coupling efficiency, and optical logic a series of issues such as devices. The world's first monolithic optoelectronic integrated chip based on standard CMOS manufacturing process, marking the future development of optoelectronic integrated chip to smaller size, lower power consumption and cost.
(2) Hybrid optoelectronic integration
Hybrid optoelectronic integration is the most studied optoelectronic integration solution at home and abroad. For system integration, especially for core lasers, InP and other III-V materials are a better technology choice, but the disadvantage is high cost, so it must be combined with a large number of silicon technologies to reduce costs while ensuring performance. In terms of the specific technical realization approach, take a company in the United States as an example, which combines active chips such as lasers, detectors, and CMOS processing in the form of different functional chipsets to common silicon through optical interconnection and electrical interconnection on passive optical adapter board. The advantage of this is that each chipset can be manufactured independently, the process is relatively simple, and the implementation is easy, but the integration level is relatively low. Universities and research institutions engaged in optoelectronic integration research have put forward optoelectronic integration technology solutions based on three-dimensional integration processes such as TSV interconnection, that is, SOI-based photonic integration layer and CMOS circuit layer realize system-level integration through TSV technology. Whether the two are compatible with each other in terms of design and structure, manufacturing processes, ensure low insertion loss of electrical interconnection, optical interconnection and optical coupling. This is the key to achieving hybrid optoelectronic integration and the main development of optoelectronic integration in the future direction.
