Anyone who has ever worked in a laboratory can appreciate the importance of environmental control. Whether the task is controlling vibration, regulating temperature, or removing particles from the air, laboratory conditions can often make or break the success of an experiment.
Nowhere is this control more important than at the National Institute of Standards & Technology, where researchers continually push the frontiers of metrology. In the past, researchers had to go to great lengths to achieve a highly controlled environment, but researchers at NIST have a new facility that will change all of that. The Advanced Measurement Laboratory (AML)--which was dedicated just two months ago (C&EN Online Latest News, June 22)--is designed to give researchers a highly regulated atmosphere.
At a cost of $235 million, AML provides strict controls over temperature, humidity, vibration, and air quality. The more than 500,000-sq-ft facility is also equipped with an uninterruptible power supply that prevents outages, spikes, and related power problems.
The facility, which is located on NIST's 578-acre campus in Gaithersburg, Md., is made up of five wings, which contain 338 reconfigurable laboratory modules and a nanofabrication facility. Two of the five wings are 40 feet underground to provide labs with a hundredth-of-a-degree-Celsius temperature control and maximum vibration control.
"We all feel very fortunate and very proud of having such a truly unique facility," NIST Acting Director Hratch G. Semerjian says. "We also feel that it is our responsibility to not only make the best use of this facility, but also to share our capabilities with other people.
"We are making an extra push to establish strategic partnerships with industry as well as with universities because we feel that we have a capability that not many other organizations--either universities or industry--are going to have," Semerjian explains. "At least, researchers could do the initial experiments here with us, and then if they convince themselves that it's really going to make a difference in their product or research," they can go back to their organization and better justify building a facility with similar capabilities, he says.
While AML now serves as a model for others to emulate, getting it built in the first place was no small task. "This was a major undertaking," Semerjian notes. He says the original discussions for the facility took place in the late 1980s when the name of the institute was being changed from the National Bureau of Standards to NIST. However, formal studies into what capabilities such a facility should have weren't available until the early 1990s.
"There was a two-step process. The first step was to assess our capabilities, the state of our laboratories, and how crowded they were," Semerjian says. "Those doing the assessment interviewed just about every technical person on the NIST campus about their laboratory and what future capabilities they might need."
"THE RESULTS of the study were all documented in excruciating detail," Semerjian says. These results were very important for decisionmakers to see, he noted, because they showed that a new facility was really needed and wasn't just someone's whim. In the end, the study identified four major shortcomings of the current laboratories: air quality, humidity control, temperature control, and vibration.
The second part of the process was an international benchmarking study that included visits to metrology facilities in Brazil, Germany, and Japan. "This study was very useful from the point of view of finding out what kind of capabilities other countries were including in their buildings," Semerjian says. "This study was also important to show other people that a facility like the one we were proposing was not a white elephant but instead was part of competing with the rest of the world," he points out.
Once the facility's desired capabilities were determined, NIST faced another challenge: proving to the contractors that it was possible to meet the stringent environmental controls. "We had to show the contractors that temperature control and vibration control could be done, because they had never done it before. The contractors had to be convinced before they bid on it," he explains.
With everything in place--including the necessary congressional appropriations--NIST broke ground for AML in 2000 and completed it four years later. Although the process from planning to completion took more than 10 years, the end product is a facility like no other in the world.
"It was worth the wait because the facility has met all of our expectations," Semerjian says. "I think they've done a super job, and believe me, this is unheard of--a project managed by the government (we actually managed the project internally) that was done on time, on budget, and meets all of our technical specifications," he says with pride.
Having advanced capabilities will clearly help NIST meet the growing demand for more sophisticated measurements brought about by rapidly developing technology. "We basically have to keep up with evolving technology, and that's why we need a place like AML," Semerjian notes.
One researcher who is looking forward to taking advantage of AML's environmental controls is John Henry J. Scott, a physicist in the Surface & Microanalysis Science Division in the Chemical Science & Technology Laboratory (CSTL). Scott's work involves using transmission electron microscopy (TEM) coupled with X-ray spectroscopy and electron energy loss spectroscopy to measure the chemical composition of materials with very high resolution.
Scott's group is also part of a NIST Competence Program. These are discretionary programs that the director awards to promising research projects. They are five-year programs that involve groups from multiple disciplines. The program Scott is working on uses scanning TEM (STEM) to create a three-dimensional image of samples at the nanoscale.
"We are basically taking a bunch of 2-D STEM data sets and synthesizing a 3-D set," Scott says. "We can do this now for structural data sets using STEM, but not for chemical composition. That's the goal of our Competence Program."
Being in AML will help Scott achieve the program's goal by providing a strictly controlled environment. In fact, Scott points out that TEM studies are very sensitive to vibration, stray electromagnetic fields, temperature variations, and humidity changes--all conditions that can be tightly regulated in AML.
Another NIST researcher excited to be part of AML is Greg J. Gillen, leader of the analytical microscopy group in CSTL. Gillen and his group use secondary ion mass spectrometry (SIMS) to understand the chemical makeup and quantity of a sample on a micrometer or smaller spatial scale.
One area of research that Gillen is involved in deals with isotopic imaging. "We are essentially a research lab that supports international atomic treaty verification by looking at uranium isotopes," he explains. In order to get precise measurements, temperature stability is very important, he notes, adding that AML will be a big help in this area.
Gillen is also working on ways to use SIMS to produce 3-D images of molecules--a process used in the semiconductor industry but not typically applied to molecular analysis, he says. Key to using SIMS to get 3-D information is the use of cluster-ion probes, which, unlike traditional ion beams, don't significantly damage the surface. This fact also makes it possible for Gillen to use cluster-ion SIMS to do depth analyses on samples of interest.
But for Gillen to extract any chemical information from the sample, it's important for the sample to remain free from dust. That's where the new lab's high air quality comes into play. "You can imagine that, if you are trying to look at a single atomic layer, a micron-thick piece of dust on the surface would effectively mask it," he explains.
Having a clean sample is also important in the labs of Roger van Zee and James Batteas, both research chemists in the surface and interface research group in CSTL. The two are working in the area of molecular electronics on a project that is also part of a Competence Program. They are interested in using molecules as electronic components because molecules are inherently small, they can be made to aggregate or self-assemble, and they can be functionalized using synthetic chemistry.
"What we are thinking about here at NIST is how to make physical and electrical measurements similar to those that exist for silicon-based electrical components on components that are molecular," van Zee explains. "For example, if you just take a voltmeter and hook it up to a molecule, what key measurements can we make available in the form of reference data that will accelerate the development of this technology in a broad-based way by business?"
To help study these systems, van Zee and Batteas use a range of techniques that include scanned probed microscopies and two-photon photoemission. For scanned probed microscopies, such as scanning tunneling microscopy and atomic force microscopy, controlling environmental vibration is critical, and that's just what AML allows, Batteas explains.
The new facility will also make running two-photon photoemission experiments easier, van Zee says. This technique uses complicated laser systems with long path lengths to excite samples to study their electronic levels and track electron relaxation effects. The smallest change in the laser path length can translate into a significant difference at the sample, which requires a lot of time to get everything realigned. "Since length is temperature dependent, having temperature controls cuts down on the setup time of each experiment," van Zee explains.
It's this reduction in experiment setup time that is perhaps the most important advantage of AML. Although work such as that of Scott, Gillen, van Zee, and Batteas was already being done at NIST, it was just much more complicated, Semerjian points out.
"IN THE PAST, our staff would spend time building boxes in boxes in boxes to create a tiny volume of environment that met the necessary experimental requirements," Semerjian explains. "Now that's done, and they don't have to worry about it. They can spend their time a lot more effectively by thinking about the next problem they're going to address."
Allowing researchers to move forward is essential for NIST, as the agency must develop the standards and measurements necessary to enable tomorrow's technology. For this to happen, NIST must stay a step ahead of industry and anticipate its needs.?
"We've got to be at the top of the pyramid," Semerjian says. To do this, NIST works closely with industry to make sure that arising needs are met.
"We are truly here to help industry innovate and move the technology along by providing them with better and more improved, sensitive, and selective measurement capabilities," he explains. "We also give industry the standards that enable them to meet all the relevant regulations--both U.S. and international ones--without any questions."
The new facility will only add to NIST's reputation as a world leader in metrology. "Now that we've moved into AML, our measurement uncertainties are going to be reduced significantly," Semerjian points out, adding that "AML is as close to perfection as we can come today."
The building of a state-of-the art lab like AML is something that the people involved will tell colleagues about for the rest of their lives, Semerjian says. "It was that kind of a job where everybody was so proud to have been a part of it," he adds. "It is the creation of a unique facility."