Wafer-Scale Testing Service (WST)

Full 8” wafer optical yield mapping before dicing – propagation loss · insertion loss · C-band 

A single die measurement tells you what one device achieved. A wafer map tells you what your process delivers – across your wafer, every run. Our automated wafer-scale service measures optical performance across an 8” wafer in a single uninterrupted run, giving foundry teams and device developers the spatially-resolved yield data they need before any downstream commitment is made. 

What sets this service apart

  • Full wafer coverage in a single automated run: Dies across the 8” wafer tested to the same calibrated standard. 
  • Pre-dicing decision point: Optical performance data before the wafer is diced and before packaging costs are incurred – yield failures identified at the earliest possible stage. 
  • Wafer maps, not just device values: Spatially-resolved maps of propagation loss and insertion loss across the full wafer – uniformity and run-to-run consistency that single-die measurements cannot reveal. 
  • ficonTEC platform: Built on the ficonTEC system – trusted by leading photonic foundries for automated wafer-scale testing – with precise automated fibre-to-chip alignment across the full 8” wafer area. 

Measurement capabilities 

Propagation loss mapping 

  • Waveguide propagation loss measured at different locations across the full 8” wafer 
  • Cutback test structure methodology – loss extracted per measurement site and aggregated into a full wafer map 
  • Strip and rib waveguide geometries supported 
  • Results reported in dB/cm 

Insertion loss mapping 

  • Fibre-to-chip coupling efficiency characterised across the wafer 
  • On-chip component insertion loss: splitters, MMI structures, directional couplers, and other passive elements 
  • Results mapped across the wafer to reveal spatial trends and identify process-induced outliers 

Measurement conditions 

  • Tunable laser source covering the C-band (1520 – 1630 nm) 
  • Automated fibre alignment to grating couplers 
  • All measurements performed on unpackaged, undiced 8” wafers 

Who this is for

Whether you are a foundry team monitoring process yield, a device developer seeking performance data before committing to dicing and packaging, or a research group characterising a new photonic platform at scale, our wafer-scale test service provides the throughput and statistical coverage you need to make informed decisions with confidence. 

  • Foundry process monitoring and run-to-run yield tracking 
  • Pre-dicing yield assessment before packaging investment is committed 
  • Within-wafer uniformity characterisation for process optimisation 
  • New photonic platform development requiring statistically significant device data