Edwin L. Aguirre
We all know the importance of keeping our surroundings clean. That’s why we dust off and vacuum our homes and cars regularly to keep dust, smoke and other airborne allergens to a minimum.
In nanomanufacturing and scientific research, a clean environment is not only desirable, it’s essential. That’s why an integral part of UMass Lowell’s newly inaugurated $80 million Emerging Technologies and Innovation Center (ETIC) on North Campus is a “clean room” facility, where the air inside is continuously circulated, filtered and monitored to make sure that the number of microscopic particles present doesn’t exceed the maximum allowable limit.
“Semiconductor and other submicron devices are very vulnerable to many types of contamination, such as particles, metallic ions, chemicals and bacteria,” says Thomas Ferraguto, director of ETIC’s Nano Fabrication Laboratory Clean Room. “When things are this small, you need a hyper-controlled environment.”
In addition to meeting critical criteria for temperature, humidity and vibration, the building houses Class 100, Class 1,000 and Class 10,000 clean-room spaces. The classification refers to the maximum number and size of particles — in microns — permitted per volume of air. (A micron is a millionth of a meter — for a sense of how small it is, the human hair measures about 100 microns wide.)
In the Class 100 clean room, only 100 particles measuring about 0.5 micron are allowed per cubic feet of air; in Class 10,000, only 10,000 such particles are permitted. In comparison, an ordinary room can contain as many as 1,000,000, or more, particles per cubic feet.
How Does the ETIC Keep the Room so Clean?
“Clean air is forced down by large fans over the work area through high-efficiency particulate air [HEPA] or ultra-low penetration air [ULPA] filters,” says Ferraguto.
Researchers working in the facility have to wear protective garments, such as lint-free hoods, face masks, coveralls, gloves and boots, to prevent contamination, he adds.
The ETIC features both positive-pressure and negative-pressure clean-room spaces. In the positive-pressure room, the air pressure inside is greater than the outside, preventing contaminants from entering the room. In the negative-pressure room, the air pressure is lower than the outside, preventing potentially hazardous particles or vapors from leaving the room.
“In this case, your concern is not what gets into the room, but what gets out,” notes Ferraguto.
Now Open for Business
The ETIC is designed to be a place where faculty and student researchers engage with industry to meet its challenges and help improve people’s lives in the region and the world. Among the University’s research thrusts are various fields in nanomanufacturing, including flexible electronics, biosensors and photovoltaic arrays.
“The ETIC is where scientists from both public and private companies can perform cutting-edge research using state-of-the-art equipment,” says Ferraguto.
The University spent $6 million to construct the clean room and is spending another $6 million for new equipment. This includes an Oxford Instruments Plasmalab System 100 for reactive ion etching and plasma-enhanced chemical vapor deposition, an Aixtron 4-inch Black Magic system for carbon nanotube and graphene production, a Raith 150-two for electron-beam lithography and a Cambridge Nanotech Fiji for plasma-assisted atomic layer deposition.
“The ETIC’s clean room is the largest, most modern and well-equipped facility of its kind in a public university in New England,” says Ferraguto.