Clean Room

A clean room is a work area in which the air quality, temperature and humidity are highly regulated in order to protect sensitive equipment from contamination. Clean rooms are important features in the production of silicon chips, hard disk drives and nanotechnology. The air in a clean room is repeatedly filtered to remove dust particles and other impurities that can damage the production of highly sensitive technologies.

The measure of the air quality of a clean room is described in Federal Standard 209. Clean rooms are rated as "Class 10,000," where there exists no more than 10,000 particles larger than 0.5 microns in any given cubic foot of air; "Class 1000," where there exists no more than 1000 particles; and "Class 100," where there exists no more than 100 particles. Hard disk drive fabrication requires a Class 100 clean room. People who work in clean rooms must wear special protective clothing called "bunny suits" that do not give off lint particles and prevent human skin and hair particles from entering the room's atmosphere.

The Physics & Astronomy Clean Room was constructed through the joint support of the KU High Energy Experiment group working within D0, the Condensed Matter Experiment group, and the University of Kansas. Within the D0 project, KU's role was the testing of the sensitive electronic components of the D0 upgrade. Beginning with an unstuffed (without surface mount components) circuit based on a Beryllia ceramic substrate that is called a hybrid, the hybrid was tested for continuity and shorts, and then shipped off to be stuffed with resistors and capacitors. The stuffed hybrids were returned to KU where further testing was done. After being tested for the correct resistance between the pads, the hybrid was shipped off for the SVX4 chip mount at D0.

For nanotechnology projects, the Clean Room is equipped with the capability of fabricating electronic devices at micrometer to nanometer scales.The microfabrication facilities are located in the class 100 cleanroom and the class 1000 cleanroom. Major pieces of equipment include: including Deep UV Mask Aligner, e-beam evaporator, plasma etcher, wire bonder, coordinate measurement machine, and probe station. The manufacture specified feature dimension is in the range of 0.2-0.3 micrometers.

The nanofabrication is carried out in a Jeol 6380 scanning electron microscope (SEM) equipped with Nabity e-beam lithographic package for electron beam lithography. Device feature dimension in several to tens of nanometers has been demonstrated. The same SEM can also be applied to image the samples and fabricated electronic devices. The spatial resolution is as small as 3 nanometers.