From Applied Materials, Inc. comes a new eBeam metrology system. The new system is specifically designed to precisely measure the critical dimensions of semiconductor device features patterned with extreme ultraviolet (EUV) and emerging high-numerical aperture (NA) EUV lithography.

Chipmakers use critical dimension scanning electron microscopes (CD-SEMs) to take sub-nanometer measurements of patterns once a lithography scanner transfers them from a mask to a photoresist. These measurements continuously calibrate lithography process performance. This ensures the patterns are correct before they are etched into the wafer. Also, CD-SEMs are used after etch to correlate intended patterns with on-wafer results. Thereby, CD-SEMs help control the etch process and enable a feedback loop between lithography and etch. This process gives engineers highly correlated data sets for holistic process tuning.

Measuring the critical dimensions of semiconductor device features becomes more challenging as photoresists get thinner with EUV and especially high-NA EUV. To capture high-resolution images that provide accurate, sub-nanometer measurements, the CD-SEM must be able to precisely apply a narrow eBeam to the small area occupied by the extremely thin photoresist. eBeam energy interacts with photoresists, and if the landing energy is too high, the resist will shrink, distorting the pattern and creating errors. Conventional CD-SEMs cannot produce beams narrow enough to create high-resolution images at landing energies low enough to minimize interactions with the delicate high-NA photoresist.

VeritySEM® 10 CD-SEM Metrology System

Applied’s new VeritySEM 10 system features a unique architecture that enables low landing energy at 2× better resolution compared to conventional CD-SEMs. Also, it provides a 30-percent faster scan rate to further reduce interaction with the photoresist and increase throughput​. The system’s industry-leading resolution and scan rate provide improved control of EUV and High-NA EUV lithography and etch processes. This helps chipmakers accelerate process development and maximize yield in high-volume manufacturing.

Moreover, chipmakers adopt the VeritySEM 10 system for critical dimension metrology applications in 3D designs. These include Gate-All-Around (GAA) logic transistors and 3D NAND memories, where the system’s back-scattered electrons enable high-resolution imaging of deep structures. Among the applications for GAA chips, the VeritySEM 10 measures and characterizes the selective epitaxy process, which is key to transistor performance. For 3D NAND memories, the system provides a large field of view and high depth of focus to measure entire staircase interconnect structures and help tune etch process recipes.

“The VeritySEM 10 system is a breakthrough in CD-SEM technology that solves the metrology challenges of major technology inflections that will shape the industry in the years ahead,” said Keith Wells, Group Vice President of Imaging and Process Control at Applied Materials. “The system’s unique combination of low landing energy, high resolution and faster imaging speed helps pave the way to High-NA EUV, Gate-All-Around transistors and high-density 3D NAND.”

The VeritySEM 10 system is receiving strong commercial interest from leading logic and memory customers, with more than 30 systems shipped over the past year. Multiple customers selected the system as the development tool of record for GAA transistors. All leading 3D NAND customers chose the system as the development and process tool of record. Also, multiple DRAM customers selected it as the process tool of record.