Integration of optical polymer pillars chip I/O interconnections with Si MSM photodetectors

We demonstrate the process integration and characterization of mechanically compliant optical polymer pillar chip I/O interconnections with Si metal-semiconductor-metal photodetectors (MSM-PDs). Polymer pillar waveguides with various cross-sectional geometry, size, and aspect ratio are fabricated on the active area of Ti-Si-Ti MSM-PDs. Some of the key performance metrics of the MSM-PDs before and after the process integration are reported. It is shown that the dark current of passivated Ti-Si-Ti PDs does not degrade as a result of the processing required to fabricate the polymer pillar I/O interconnections. In addition, the pillar integration does not degrade the responsivity as well as the normalized photo-to-dark current ratio of the MSM-PDs.