Cleanrooms with a system of raised false floors are commonly used in semiconductor manufacturing factories (fabs), Nanofabs, Nanotechnology Centers and other precision manufacturing and research facilities to accommodate complex facility requirements (plumbing, electrical cables, gas piping, etc.) and to maintain proper cleanliness standards.
Installation of vibration-sensitive manufacturing, inspection and metrology equipment is difficult on such floors.
The elevated flooring is unable to offer the quiet vibration environment that such equipment requires. The Quiet Island® from TMC is a unique solution that replaces a piece of the elevated floor with a “Quiet Island” attached to the sub-floor below. The Quiet Island is made up of a cleanroom-friendly platform top and an application and site-specific support structure.
Vibration Cancellation
The STACIS III Active Vibration Cancellation System is Quiet Island’s major support element and core technology. This “rigid” type inertial vibration cancellation support system is vital for any vibration-sensitive instrument, allowing them to perform at its best in a noisy environment.
STACIS III works with automated wafer-processing equipment, ion-beam milling tools, high-resolution eBeam imaging tools, and any other tool with passive or active internal vibration isolation systems (see the white paper on stacking active on active isolators).
It also offers the best vibration isolation across the commercially accessible frequency range. Furthermore, the “hard-mount” design is highly rigid, ensuring that tall, top-heavy equipment is stable.
STACIS IIIc isolators can be used to create a more compact version of the Quiet Island for extremely short raised floors.
Risers and supports
TMC’s skilled engineering team designs very strong and durable risers to support STACIS isolators, which are then built to high standards with welding certifications at the ISO 9001 plant. Each Quiet Island is designed to accommodate a wide range of raised floor heights, subfloor geometries, and tool footprints.
TMC has the experience and knowledge to develop a support system that meets the demands of STACIS and the facility, with thousands of installations worldwide supporting over 200 distinct instrument models.
Rigid platform
The raised floor platform is a 4-inch (100 mm) thick steel plate lamination that is sandwiched around a lightweight, incompressible, damped core material developed and manufactured by TMC. The layering effect of rigid steel plates and core, epoxy bonded to a seamless, stainless steel pan gives an incredibly high level of structural rigidity and damping.
Overall rigidity is quite high because of the wide cross-section and steel composition. To maintain cleanliness, appearance and integrity, the top and sides are a continuous, one-piece stainless steel shell. TMC creates platforms that are tailored to the application, including cuts, unusual shapes, tiedown holes and elevating bolts as needed.
Quiet Islands vs. Quiet Buildings
Designing a facility to fulfill the stringent Vibration Criteria of very accurate imaging equipment can be difficult and expensive, especially when not all of the facility’s instruments require these extremely low vibration levels.
Isolating huge regions, such as entire buildings or floors, is extremely challenging. It is also widely established that as a facility fills with equipment and people, building vibration levels rise over design specifications. Floor vibration levels often grow with time, as measured by repeated vibration measurements a few months or a year later.
Employing point-of-use active vibration control with serial piezoelectric technology is a more cost-effective and successful way of meeting the stringent criteria of vibration-sensitive equipment, notably to minimize problematic low frequency (less than 5 Hz) vibration.
TMC may collaborate with the team to create a Quiet Island solution tailored to the unique tool. This method allows users to examine each instrument individually and propose the most effective solution. A building design that has a single huge concrete sub-floor “slab” with a “raised floor” enables tool selection flexibility after construction.
Replacing the elevated floor with a Quiet Island, only when needed, offers the most sensitive toolset with a vibration environment that is at least an order of magnitude lower than the sub-floor.
Statistical representation (in terms of Mean plus Sigma Spectra) of vertical vibrations in a typical semiconductor fab production area at “as built” and two times thereafter. Image Credit: TMC Vibration Control
The Quiet Island advantage
- Incorporates STACIS - TMC’s active piezoelectric vibration cancellation technique is unrivaled in the industry, with a “hard mount” design and isolation starting at 0.6 Hz, making it compatible with tools with internal isolators.
- Modularity, customization and relocation flexibility - Unlike concrete plinths, each platform is suited to the customer’s application but can be simply modified if the tool or floor parameters change.
- Expertise - TMC has extensive expertise working with leading semiconductor manufacturers, scientific institutions and ultra-precision OEMs across the world. Designers understand the clients’ requirements. Specialists develop and produce everything individually.
Performance
Measured transmissibility on a 24” tall 40”x60” Quiet Island, 4-mount STACIS support, VC-C input from the floor. Image Credit: TMC Vibration Control
Specifications
View STACIS® III for vibration isolation specifications.
Source: TMC Vibration Control
| . |
. |
| Platform surface |
Stainless steel surface top and sides; epoxy painted steel bottom |
| Platform construction |
Proprietary multi-layer steel laminate |
| Dimensions |
Build to suit |
| Standard heights |
15, 18, 20, 24, 30, 36, 48 in.
38, 46, 51, 61, 76, 91, 122 cm
Custom heights also available |
| Load capacity |
Build to suit |
| Rigid risers and supports |
Certified welding, all-steel construction, cleanroom compatible powdercoat finish |
| Options |
Restraint brackets, platform top eyebolts for lifting, bridge plates for waffle-type subfloors |
| Platform top variations |
Cutouts, thru-holes, tapped holes for tool tie-downs |
Other Quiet Island Configurations
Large instruments that do not have an environmental vibration specification frequently require solid and stable support that is distinct from the elevated floor. The Rigid Quiet Island is an excellent choice. Rigid Quiet Islands are specially developed for installation in raised floor cleanrooms with any height, any sub-floor geometry, and a range of tool footprints, all with the same high-performance platform top.
TMC supplies a variety of support posts to meet a variety of needs, resulting in a solution that is tailored to the instrument and Fab while also being modular, relocatable, and upgradeable.
Image Credit: TMC Vibration Control
Image Credit: TMC Vibration Control
Application photos
Image Credit: TMC Vibration Control
Image Credit: TMC Vibration Control
Image Credit: TMC Vibration Control
Image Credit: TMC Vibration Control
Image Credit: TMC Vibration Control
Videos
TMC Quiet Island for Cryo Electron Microscopes
Typical setup of a Quiet Island under a cryo electron microscope.
Video Credit: TMC Vibration Control
TMC Vibration Control -- STACIS 2100 installation
Quiet Island isolated raised floor installation steps.
Video Credit: TMC Vibration Control