New Release: Beamfox Proximity v1.9.0

We are thrilled to announce the release of feature update 1.9.0 of Beamfox Proximity! The update is loaded with several highly requested new features, as well as major enhancements and improvements. Upgrade your existing installation or download our free, fully featured 30-day trial over at the Downloads page today, or read on to learn all about what is new in 1.9.0.

Unique layer dose targets

With feature update 1.9.0, we have added the feature to set custom, unique dose targets for specific layers, enabling a large swathe of new applications and use-cases that require going beyond using a fixed global dose target. This new functionality is especially useful for exposing patterns in multiple resist layers, utilizing ghost layers to artificially increase the dose in specific areas useful for, e.g., producing a controlled undercut, and exposing patterns on partially suspended thin membranes.

To enable setting custom layer dose targets, simply enable the Unique layer dose targets (experimental) option in the Advanced settings menu. Once enabled, an input field is displayed next to all layers in the Layers menu, where the custom dose targets can be set.

Demonstration of the Unique target dose layers feature. Four squares in separate layers are assigned target doses of 0.5, 1, 2, and 5, respectively. The proximity-effect correction ensures that each square will be exposed to match its assigned target dose.

With custom dose targets set, running proximity-effect correction corrects the exposure doses of the entire pattern, taking the dose targets into account. The result is a proximity-effect corrected mask, where the exposure doses of the pattern in each layer are corrected such that the resulting dose will match the assigned target doses.

This feature is currently marked as an experimental feature, as it has not been verified for all applications and use cases. Users are encouraged to thoroughly review output files when using this feature.

Improved point-spread function simulation

A number of improvements have been made to the underlying point-spread function (PSF) simulation and fitting algorithm, improving the robustness, accuracy, and reliability of the PSF fitting. Using the Automatic mode in Beamfox Proximity now provides fits of the PSF with even higher accuracy, as well as more consistent results from simulation to simulation.

To take advantage of the improved fitting, users can now toggle the newly added Recalculate PSF option under the Point spread function menu. When enabled, the PSF will be re-simulated for the given material stack and will replace the existing PSF stored in the database.

Zero-area objects support

We have added support for zero-area objects – single shots and single-width lines – when exporting to select Elionix file formats. With the Elionix zero-area objects detection (experimental) setting enabled in the Advanced settings, Beamfox will automatically detect these objects, proximity-effect correct them accordingly, and export them using the corresponding unique object type in the output file.

Using zero-area objects with Beamfox Proximity is straightforward: simply define the objects within the GDS file directly. Single-width lines are defined using paths with the width set to zero, and single shots are defined with paths consisting of a single point, with the width similarly set to zero.

Array of single shots and single-width lines proximity-effect corrected using Beamfox Proximity.

Working with zero-area objects requires setting the Effective beam width FWHM (nm) in the advanced settings. The effective beam width is the full width at half maximum of the measured beam width for the given process, which includes contributions from the beam spot size, short-range scattering, as well as process and development effects. For optimal results, it is recommended to enable the Forward scattering correction (experimental) feature when correcting zero-area objects.

This feature is currently marked as an experimental feature, as it has not been verified for all applications and use cases. Users are encouraged to thoroughly review output files when using this feature. The handling of zero-area objects is currently only supported when exporting to the Elionix SCON and CAR file formats.

Further upgrades/improvements

  • Streamlined the Output menu for CAR export
  • Improved the efficiency of path to polygon conversion
  • Improved general robustness and handling of edge cases
  • Improvements to the command-line interface