The 21st On-Wafer Forum held during IMS2025 and ARFTG-105 in San Francisco brought together 34 participants from industry, metrology institutes, and academia to explore the latest advances in wafer-level measurement and calibration.

Andrej Rumiantsev (MPI Cooperation) opened the session with “Towards a Framework for Characterizing System and Calibration Drift Across Temperatures”, setting the stage for in-depth discussion on thermal management strategies to minimize temperature-induced drift in wafer-level measurements at mmWave frequencies.

Ziad Hatab (Keysight Technologies) followed with a presentation on customized multiline TRL calibration for planar DUTs. His talk provided practical guidance on designing mTRL calibration kits with reduced parasitics, supporting more accurate and robust high-frequency characterization.

Faisal Mubarak (VSL) concluded the session with results from an inter-laboratory on-wafer S-parameter comparison spanning six frequency bands from 10 GHz to 1.1 THz. Conducted across seven laboratories using equipment from multiple vendors with varying probe pitch sizes, the comparison demonstrated excellent cross-lab consistency underscoring the increasing reliability of wafer-level metrology in the sub-THz bands.

The strong attendance and active engagement throughout the forum reflect a growing interest in practical, temperature-aware calibration strategies, on-wafer calibration and cross-laboratory reproducibility at the frontier of on-wafer measurements.