Scientific Instrumentation
CXRO creates and operates advanced experimental systems to address national needs, support research in material, life, and environmental science, and extend the forefront of semiconductor manufacturing. Behind each of these systems is a team of engineers who design, build, and commission some of the most precise instruments in the world. The projects below show examples of precision engineering at CXRO.
SHARP
SHARP is a highly flexible mask-imaging microscope built to support semiconductor research. It is the world’s highest-resolution EUV microscope, enabling the characterization of mask defects in great detail. The CXRO engineering team designed, built, and commissioned SHARP at Advanced Light Source beamline 11.3.2 in 2013, and has delivered a steady series of upgrades since:
- Tilting zone plate holder (2014)
- Interchangeable flexures and mask presence sensor for the mask holder (2014)
- Automatic mask handling system, a CXRO and Intel collaboration, and adjustable shutter system (2015–2016)
- Laser interferometry encoders for the mask and zone plate stages (2016)
MET5
The Berkeley MET5 is an EUV projection lithography tool at the ALS. With a depth of focus of 30 nm, the 0.5 NA tool requires 1 nm resolution metrology in the three linear directions and 100 nrad in tip and tilt, with wavefront errors below 0.5 nm RMS. MET5 has a proven optical resolution of 7.5 nm (half-pitch) and 0.8 nm stabilization over exposure times as long as one minute. The instrument combines a two-mirror objective with nanometer-resolution precision stage systems and a support and metrology system engineered for high stability. The mechatronics are designed to hold off drift, which allows even very slow experimental resist materials to be characterized.
The CXRO engineering team designed, built, and commissioned the MET5 facility at ALS 12.0.1.4 in 2019, and has continued to upgrade it, improving vibration from 1.5 nm to 1 nm RMS and commissioning a standalone EUV source.
AIRES
AIRES (Actinic Image REview System) is a plasma-source-based ultrahigh resolution zone plate microscopy tool that addresses the industry need for EUV mask imaging and defect printability studies. A standalone discharge-produced plasma source provides EUV light to the tool. The CXRO engineering team developed the architecture and design of AIRES, including a solution to mitigate the impact of ground motion on system performance. The optical column hosts a monochromator that significantly narrows the wavelength, allowing unique CXRO-developed zone plate optics to be used. The system produced its first image in January 2020. CXRO later delivered a new monochromator upgraded with motorized stages that improved throughput by a factor of two.
TPI
Lithography masks act as the master copy from which wafers are printed, so they must be inspected to identify any defect. It is also essential that no particles land on the mask. Pellicles, thin membranes placed a few millimeters above the mask, keep particles off the imaging surface. In 2022 the CXRO engineering team installed the TPI (Through Pellicle Inspection) mask inspection tool at ALS beamline 11.3.2. TPI features a working distance long enough to focus past the pellicle. The TPI microscope is among the highest resolution EUV microscopes in the world, capable of imaging mask features at a half-pitch of 25 nm, with potential for even greater resolution using higher-NA zone plates.
