ASELTA operates in the IC manufacturing world, and provides advanced software solutions for wafer and mask patterning based on e-Beam technology. ASELTA is enabling the use of e-Beam lithography equipment for all advanced technology nodes such as 28nm and beyond.
Smaller geometries following Moore’s law are now requiring the need of using e-beam writer, whether on direct write wafer patterning equipment or mask patterning manufacturing equipment.
The challenge of using ebeam writing equipment is to trade off between the writing time, which correlates to cost, and the pattern fidelity , which correlates to quality.
The electron beam behavior in such equipment can be predicted and corrected using a deterministic algorithm like Proximity Effect Correction.
e-beam Proximity Effect Correction
Direct write equipment has been using for some time e-beam Proximity Effect Correction (PEC) in order to reach targeted resolution; but the old algorithms are running out of steam.
As semiconductor devices push into the 20-nm process node and beyond, advanced critical masks written by e-beam writers can run into the issue of days for write time, therefore triggering exploding costs. And, the challenge is augmented by pattern fidelity issues like resolution, accuracy, uniformity, hotspots...
So there is a need for new generation of model based correction technology taking into account the e-beam PEC and being able to trade off pattern fidelity and writing time.
The need of increased resolution is not new within the Ebeam direct write on Silicon equipment. ASELTA, created initially to help supporting the direct write market, has now a mature technology already deployed in the direct write community.
ASELTA methods and algorithms , are now being used in the mask manufacturing world. Serdar Manakli started to focus on the proximity effects correction for e-beam while working at ST & CEA-LETI during earlier 2000’s. So the company foundations are based on deep user and technology knowledge.
Advanced e-beam machines
During 10 years, ST and CEA-LETI e-beam teams worked on advanced e-beam machines : 3 VSB Vistec machines and two Gaussian machines, Advantest (standard and cell projection option tools), Mapper, IMSnano, Jeol and NuFlare but also deeply analysed others multibeam platforms like KLA-Tencor, multibeam systems.
Data preparation for ebeam machines
Nobody has to be told of the complexity and ever-growing data volume as designs move further along the technology curve. The increase of transistors per square mm translates to exponentially growing figure counts that dictate truly hi-performance computational methods just to keep up. But since the beginning, the ideas of distributed processing and efficient handling algorithms have been the foundation for mask data processing at ASELTA. PEC algorithms require so much more than just simple data fracturing into machine formats. ASELTA has been addressing such computational requirements with scalable hardware and software solutions suited for today, and tomorrow.
EU Programs – worldwide consortium
MAGIC : From January 2010 to March 2011, ASELTA has led the European MAGIC program working on the analysis of multibeam proximity effects correction and the accuracy of the simulation.
IMAGINE : Since 2010, ASELTA has worked on the development of Mapper multibeam platform and its introduction in IC mass manufacturing. ASELTA continues to develop its INSCALE product on Mapper interface, data preparation and proximity effects steps.