International Image Sensor Workshop (1)

Some thoughts about day 1 :

  • Sony showed that they are ready for hybrid bonding on pixel level with a pitch of 2 um (on teststructures) and 4 um in a real imager with 1 um pixel pitch,
  • A collaboration between TSMC and Qualcomm illustrated a stacked image sensor on top of an FPGA,
  • According to Omnivision, the pixel race is picking up again.  This was illustrated by an imager with a pixel pitch of 0.9 um, with the same performance as the 1.0 um pixel,
  • Fermi Lab showed an very complex die-to-wafer-to-wafer structure,
  • TSMC realized a 4T pixel in which the charge transfer (underneath the transfer gate) is no longer taking place at the interface but deeper into the silicon.  Also this was demonstrated in a device with 0.9 um pixel pitch with an improved noise performance,
  • TechInsights give a great (historical) overview of PDAF pixels and stacking.  Although they tell what others are doing (or have been done), still a lot of interesting details were shown,
  • BAE illustrated that dark current is reduced over the years by a factor of 5000, and that we now have a temperature behaviour according the Eg-law, while in the past it was the Eg/2-behaviour.  Unfortunately (or maybe fortunately), still not all dark current secrets are yet revealed,
  • TowerJazz illustrated a pinned-storage node in a global shutter pixel with 2.8 um pixel pitch (is this global shutter CIS with 2.8 um seen elsewhere in a product of … ?)
  • Fluorine implant is used to lower the noise in a CIS, this was presented by Dongbu,
  • Random Telegraph Noise got quite a bit of attention, talks from TSMC and twice Tohoku University showed a lot of measurement results to further explain and understand the RTN effect,
  • On-chip near-IR filter for colour imaging was presented by VisEra.  This is an attractive alternative to the classical near-IR filter because it makes the height of the camera-module lower.

It is impossible to write about every single paper.  On day 1 there were 17 presentations plus 45 posters, an incredible amount of details and information.  But the good news is that all papers will become on-line (open access on www.imagesensors.org) in about 2 or 3 months from now.

 

Albert, 30-05-2017.

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