Ultra-High Resolution & Ultra-High Sensitivity
Scatterometer and Thin Film Measurement System
for Photomask or Semiconductor Wafer Applications
The n&k Gemini series are automated metrology systems used to fully characterize and monitor Thin Film and OCD applications for both current and next generation IC processes. Capable of simultaneous Reflectance and Transmittance measurements the Gemini series is ideal for applications with transparent substrates (i.e., Photomasks, SiC Wafers, Quartz Wafers, Flat Panels, etc.).
Utilizing patented all-reflective optics, a broadband wavelength range (190 – 1000nm), proprietary optical formulation, and an industry leading signal-to-noise ratio, each system provides the accurate and reproducible data required to monitor subtle changes in critical device parameters (thin film thickness, optical properties, critical dimensions (CD), poly recess profile, sidewall angle) across various key applications.
In this example application, the desired measurement output is the degree of rounding of contact holes in MoSi on quartz.
The figure on the right shows the sensitivity of the raw reflectance and transmittance data to corner rounding. The high sensitivity of the transmittance data allows for accurate measurements of this quantity. Also note the high level of the transmittance (65% at 800 nm) compared to the reflectance (15% at 800 nm). This high level improves the signal-to-noise and hence the repeatability of the measurement.
This example illustrates the importance of the n&k Gemini’s unique transmittance capability in achieving accurate and repeatable results.
As critical dimensions (CD) become smaller, mask manufacturers increasingly use phase shift technologies to enhance the resolution of the resist image that is formed on the wafer
The n&k Gemini determines phase shift from 190-1000 nm through R and T measurements and through the analysis of film optical properties, film thickness and quartz etch depth.
The n&k Gemini can measure structures used in EUV lithography, as well as the thickness and n and k spectra of the associated materials.
Using measurements on blanket areas, the thicknesses and n and k spectra can be found for: