CMP Pressure Distribution Study Group Final Project Update By Dave Bullen Alia Koch Alicia Scarfo 7/30/1999

Overview Previous work Photos: The Jumbo 1000 in action Data collection software redesign Final static and dynamic pressure data Numerical work on pad deformation

Previous Work Manometer Testing –Response was to slow –Could not measure a wide enough range Pressure Gage Testing –Adequate response time –Still could not read a wide enough range –Could not be used with a rotating wafer

The Jumbo 1000 in Action

Data Acquisition LabVIEW helped because: –Real Time Data –Very Accurate Data from Transducer –Easier to Read Data –Other Calculations made in Real Time

The Program We were able to control: –Scan Rate –Scans per Channel –Total Scan Time –Total Number of Scans

Our Front Panel

Wafer Static Pressures

Pressure distribution is divided into two high pressure regions and two low pressure regions There is a wide variation in the pressures from point to point There is a vague increasing trend from rim to center

Wafer Dynamic Pressures

Pressure distribution structure is similar to the static structure Less variation from point to point There is a strong increasing trend from rim to center

Accomplished Numerical Goals Wrote structural program –modeled pad changes using finite element methods –wrote program in Fortran 77 compatible with current Fidap fluid finite element program

Update Program now compiles! Future changes to structural FEM program –program would benefit from new mesh generator –observe effect of pad deformation on pressure distribution under the wafer Other options –try to incorporate strain program supplied by Professor Perlman

Project Accomplishments Determined the pressure distribution under a static and dynamic wafer via three methods Created a system that can monitor film pressure under a rotating wafer Used numerical methods to advance the understanding of the pad deformation phenomenon

Future Pressure Detector Work Manufacturer the rotating platform and glass wafer as specified. Add a position signal to the data stream. Upgrade the sliding contact system to transmit several channels. Redesign transducer/air purge system to further reduce the response time.

Thanks Dewi Bramono Dr. Jonathan Coppeta Dr. Livia Racz James Hoffman Joe Lu The whole TAMPL gang