Manufacturing Bits: June 27

World’s brightest laser; EUV mask inspection; $1.7M microscope.


World’s brightest laser
The University of Nebraska-Lincoln has set the unofficial record for the world’s brightest laser.

Researchers have focused a laser at a brightness of 1 billion times greater than the surface of the sun. This feat was accomplished using the so-called Diocles Laser at the University of Nebraska-Lincoln. The laser has a combination of peak power and a repetition rate of 100-TW at 10-Hz.

Diocles laser (Source: Extreme Light Laboratory|University of Nebraska-Lincoln)

The laser created various X-ray pulses, enabling researchers to observe changes in the interaction between light and matter. This, in turn, could one day enable high-resolution images for use in medical, engineering, scientific and security applications.

In the lab, researchers fired the laser at helium-suspended electrons. The goal was to measure how the laser’s photons scattered from a single electron. In the experiment, researchers scattered nearly 1,000 photons at a time. And at a certain threshold, the laser altered the angle, shape and wavelength of the photons.

“So it’s as if things appear differently as you turn up the brightness of the light, which is not something you normally would experience,” said Donald Umstadter, the Leland and Dorothy Olson Professor of physics and astronomy at the University of Nebraska-Lincoln, on the university’s Web site. “(An object) normally becomes brighter, but otherwise, it looks just like it did with a lower light level. But here, the light is changing (the object’s) appearance. The light’s coming off at different angles, with different colors, depending on how bright it is.”

Using a laser focused to the brightest intensity yet recorded, physicists at the Extreme Light Laboratory produced unique X-ray pulses with greater energy than their conventional counterparts. The team demonstrated these X-rays by imaging the circuitry of a USB drive. (Source: Extreme Light Laboratory|University of Nebraska-Lincoln)

EUV mask inspection
NuFlare and the Paul Scherrer Institute (PSI) are co-developing a technology that represents a missing piece in the infrastructure for extreme ultraviolet (EUV) lithography—actinic mask inspection, according to a paper from the recent newsletter from BACUS.

Today, traditional optical-based inspection tools are being used to find defects for EUV masks. 193nm-based optical inspection works for current EUV masks, but optical may run out of steam in terms of resolution in the future. Meanwhile, e-beam inspection can also work, but it’s slow in terms of throughput.

The industry wants 13.5nm actinic inspection, which can supposedly find more defects than optical in EUV masks. There is a problem, though. No such tool exists today.

To solve the problem, NuFlare and PSI are co-developing a technology called RESCAN, according to a paper from BACUS. The actinic defect inspection platform, which is being built at PSI, uses scanning scattering contrast microscopy (SSCM) and scanning coherent diffraction imaging (SCDI), according to the paper.

A prototype tool is installed at the Swiss Light Source (SLS). The SLS at the PSI is a third-generation synchrotron light source with an energy of 2.4 GeV. The mask inspection technology makes use of a light source called COSAMI. With a foot print of about 5- x 12m2, the source provides a “flux of about 100mW with 0.5% bandwidth,” according to the paper. The throughput for full mask inspection is 7 hours.

In operation, the reticle is illuminated with photons from a synchrotron. “The RESCAN tool is based on coherent scattering of EUV photons from the patterned reticle,” according to paper. “By illuminating a certain field of the photomask with coherent photons (typically from a synchrotron source), the far field scattering intensity is recorded on a pixel detector.”

$1.7M microscope
Washington State University is expected to become the first U.S. university to install a next-generation X-ray microscope from Zeiss.

The Xradia 810 Ultra from Zeiss enables non-destructive 3D X-ray imaging with resolutions down to 50nm. It employs advanced optics adapted from a synchrotron. The $1.7 million X-ray microscope will help Washington State University researchers to develop materials for self-healing roads, printable batteries and efficient solar cells.