Electrical Engineering
      and Computer Sciences

Electrical Engineering and Computer Sciences


UC Berkeley


2010 Research Summary

Zero-Footprint Optical Metrology Wafer

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John Gerling1 and Nathan W. Cheung

UC Discovery and IMPACT

Using a heterogenous integration approach, we have encapsulated prefabricated monolithic components, a photodiode and LED, inside a silicon wafer form factor to achieve a self-contained, environmentally sealed system for hard-to-access hostile processing environments. We have demonstrated the utility of the metrology wafer for data mapping and process monitoring in plasma, CMP, and chemical etching.

Our work now focuses on expanding the functionality of the metrology wafer to include spectral analysis. To date, we have designed and prototyped a refractive index optical dispersion stack for spectroscopy capability, calibrated wavelength dispersion and photon intensity. Proof-of-concept experiments are currently underway to show that the spectroscopy function can be used to monitor process changes relevant to the semiconductor industry via the fluorescence phenomenon.

John Gerling, Zhongsheng Luo, Vorrada Loryuenyong, and Nathan Cheung, "Zero Footprint Optical Sensor Cell for In-situ Monitoring of Membrane Absorption/Desorption of Liquids," Institute of Biological Engineering Annual Conference March 19-21, 2009

1Applied Science and Technology, UC Berkeley