IBM Corporation, T J Watson Research Center
Project Description: Vibration Sensitivity Testing of Direct-Write Lithography Equipment
IBM developed lithography equipment for producing small geometry wafers. It was necessary to understand the sensitivity of the tools to facility vibrations.
Vibration Engineering Consultants, Inc. conducted extensive on-site testing of the components to establish the loss of precision (resolution) as a direct function of base (floor) vibration. The project involved actual testing using electrodynamic shakers as the force exciters, and post-test analysis using Vibration Engineering Consultants' own software package, PCMODAL, to ultimately develop curves providing permissible displacement, velocity and acceleration linear spectra. The project established the permissible facility vibration criteria for selected IBM production equipment.
Brookhaven National Laboratories
Project Description: Facility Analysis and Conceptual Design Services For the Neutral Beam Test Facility (NBTF)
The NBTF is a new linear accelerator facility being constructed adjacent to existing similar facilities. The facility operations are extremely sensitive to on-site vibrations and vibrations caused by support equipment. An overall displacement criteria for permissible target deviation not to exceed roughly 3 microns was established.
Vibration Engineering Consultants, Inc. was retained to measure the site vibration characteristics, and provide analytical and design recommendations in a conceptual form to Brookhaven and the Architect/Engineer. To that end, on-site measurements were made to establish the proposed site vibration characteristics. In addition, as the support machinery to be used in the NBTF was essentially the same as existed in the LINAC accelerator, measurements were made of the vibration signatures of the support pumps, compressors and motors. This data was used in an evaluation of the conceptual design of the NBTF and design recommendations were offered regarding foundation design, equipment isolation, and most importantly, the quadrupole magnet monuments. Post-construction tests were conducted to confirm the engineering criteria had been met.
Project Description: Analysis and Retrofitting of Sensitive Equipment Laboratory at the General Technology Division, Building 967
IBM Corporation relocated the entire wafer inspection laboratory from Building 970 which was on grade, to the second floor of Building 967. Vibration Engineering Consultants, Inc. was charged with evaluating whether the equipment, particularly the scanning electron microscopes (SEM), would function on an elevated floor. Any remedial design measures were also the responsibility of the Consultant.
Measurements were made in Building 970 in which all the equipment was presently contained and functioning adequately. Measurements in Building 967-2 showed considerably higher vibrations. In order to achieve acceptable levels of vibration, special isolation systems were designed and some modifications were made to the equipment to harden them against the effects of vibration. After the installations began, measurements were made to ensure that the vibration levels were as designed and to verify equipment operability.
Systronics, Inc./MIT Lincoln Laboratories
Project Description: Vibration Testing and Retrofit Design of the Massachusetts Institute of Technology Lincoln Laboratories Clean Room in Bedford, Massachusetts
Lincoln Laboratories is refurbishing their clean rooms and has purchased new, greater resolution wafer fabrication equipment for the laboratory. Perkin Elmer Microalign M300 series aligners were purchased and installed in the clean rooms. Vibration Engineering Consultants was retained to measure the existing floor vibration levels in the room and compare the data to the vibration acceptability envelopes provided by Perkin Elmer for this aligner series.
The clean room has a raised floor construction with the exhaust plenum located beneath. This caused significant vibration levels throughout the floor and indicated that the aligners would not function well in the existing environment. We recommended placement of the aligners directly on the slab beneath and design of a rigid pedestal from the slab to the level of the raised floor which will ensure the operability of the component.