Cmos IC design for free-space optical-interconnect packaging

摘要

Hybrid integration of optoelectronic devices, such as GaAs MQW modulators and VCSELs, to CMOS VLSI circuits provides the oppor-tunity to design ICs that integrate millions of transistors and thousands of high-speed optical I/Os for high-performance computing and switching applications. One of the challenges in designing such large-scale ICs lies in the development of an efficient method for integrating existing VLSI circuit layouts with two-dimensional arrays of optodelctronic devices. Two reasons for this are the need to include fixed geometry and the need to communicate with non-CMOS level signals. Physical restrictions placed on the design to facilitate packaging and system-level use have to be planned for, and considered throughout the design process. Additionally, the need to interface between the digital circuits and the optical devices means that the design is no longer a strictly digital one, and again, changes must be made to take this into accunt. We have designed, fabricated and tested a variety of ICs which include optoelectronic communication. This paper will focus on how such communication has changed the design process and what approaches we have taken to include it.