Metal Film Uniformity

Sheet resistance uniformity of metal films is critical to ensure device performance, and most metal films can be measured by both 4PP and EC. EC is recommended for thicker, highly conductive metal films and 4PP for thinner metal films ( > 10Ω/sq), but very high 4PP/EC correlation ensures accurate results using either method.

The Filmetrics R54 resistivity maps highlight film uniformity, deposition quality, and other process variations. The example at left is a map of a TiWN deposition layer, showing the fingerprint of the batch reactor.

Ion Implantation Process Optimization

The 4PP probe is the standard technique for measuring ion implant processes. The Filmetrics R54 software includes I-V curve plotting and current ramp scans that can be used to optimize the current used during measurement or identify current leakage between an implant layer and the supporting silicon substrate. Contour maps and diameter scans of an ion implant after thermal annealing can identify hot and cold spots due to lamp failure, poor wafer/platen contact, or implant dose variations.

In the example at left, the process was optimized by improving the backside thermal contact. Accurate measurement of the resistance across the wafer diameter provides the necessary information to optimize the heating profile of the reactor to reduce nonuniformity.

Film Thickness/Resistivity/Sheet Resistance

Measured wafer data can be mapped as sheet resistance, film thickness, or resistivity. By entering a resistivity value (or resistance-dependent function) for a material, the thickness can be calculated and displayed; the resistivity can be calculated if the thickness value is entered.

Data Acquisition and Visualization

RsMapper is the R54 intuitive user interface that combines data acquisition and analysis features into a single platform that can be used on the tool itself or for offline analysis. Data acquisition for measurement sites can be easily specified using a variety of coordinate layouts.

The RsMapper platform can display 2D/3D measurement results for quick visualization of critical film uniformity data, as shown for the ion beam scanning issue shown at left. The software easily switches between maps of individual measurement parameters and rotatable 3D profiles to deliver customized views of the process parameters. SECS/GEM basic interfacing is available for remote benchtop operation.