Modern EBL systems have a high depth of focus of several hundred nanometers and can correct for large-scale wafer height variations of several hundred microns. This makes it useful with wafers that have rough surface topology, such as those of gallium nitride (GaN). EBL also allows multiple designs to be fabricated in tandem on one wafer.
However, EBL is a relatively slow and expensive process. This makes it impractical for use in production, and substrate charging and proximity error effects also need to be accounted for in order to achieve good quality devices, a requirement that adds extra fabrication steps and correction software into the design process.
With the increasing need for early-generation chips with mature nodes, mask-related costs begin to add up. Masks with less demand also have longer lead times, which is a drain on productivity.
According to Multibeam chairman David Lam, MEBL cuts prototyping cost and time because "respins" no longer require a new set of masks. “Since all e-beam columns in our MEBL system write independently and in parallel, they empower production of multi-project wafers and chips larger than the typical optical field of view,” he added.
As a proprietary platform, MEBL can reportedly be applied to ensure “security lithography” by embedding unique security information into each integrated circuit (IC) during wafer fabrication. Multibeam plans to build on this by enabling hardcoding of unique chip IDs into each IC during fabrication, something that would make counterfeiting profoundly more difficult.
even the U.S. says is inefficient and now they are backing the idea of MEBL
