Chip-level waveguide-mirror-pillar optical interconnect structure

Abstract

Waveguides, mirrors, and polymer pillars can be integrated together to provide optical interconnects to the chip level. Total internal reflection in the polymer pillar provides a high level of spatial confinement of the light. The metallized mirror terminating the waveguide may be at 45 or at a nearby angle such as 54.74 (anisotropically etched silicon) and produce nearly equal coupling efficiencies. For a polymer waveguide, a gold mirror, and a polymer pillar of the dimensions fabricated, the simulated coupling efficiencies are 80.7% or 0.93 dB (45 mirror) and 82.5% or 0.84 dB (54.74 mirror), respectively. These simulations together with the fabrication and testing of a 54.74 mirror configuration demonstrates the viability of the waveguide-mirror-pillar structure, its insensitivity to mirror angle, and its compatibility with current substrate fabrication technologies.

Power delivery, signaling and cooling for 2D and 3D integrated systems

“…Electrical chip I/O interconnection is achieved using solder bumps. The optical I/Os are implemented using surface-normal optical waveguides and take the form of polymer pins [25,26,27]. A polymer pin, like a fiber optic cable, consists of a waveguide core and a cladding.…”

3D Integrated Circuits: Liquid Cooling and Power Delivery

“…In other words, the 3D technology under consideration combines all critical interconnect functions (power, signal and thermal) for a gigascale system [24]. Details of the optical interconnects proposed for the 3D system under consideration and its advantages to other optical interconnect technologies can be found in [25][26][27]. This paper will focus on the cooling and power delivery aspects.…”

‘trimoda’ Wafer-Level Package: Fully Compatible Electrical, Optical, and Fluidic Chip I/O Interconnects

“…For successful assembly and testing of the dual-mode pins, mirror terminated waveguides were fabricated on a silicon substrate, as illustrated in Figure 12. The process that was used to integrate mirrors with the waveguides is shown in Figure 13 and is an extension of previous work [25]. The waveguide core was photopatterned using SU-8 and was 20 pm thick and 40 pm wide.…”

“…However, optical simulations demonstrate that the coupling efficiency between a waveguide and a polymer pin can be as high as 89% when using the mirrors described in [25]. 588 Figure 14: Optical images of annular shaped metallic (solder) pads fabricated around a via through the cladding layer of the waveguide.…”