Fab pit crew

A chip production line without a solid equipment-maintenance group is like a car-racing team with a mediocre pit crew. Neither will succeed without the technicians who labor in relative obscurity to maintain and repair the high-performance machinery. A recent study confirms what the best fab managers know: a motivated maintenance team can have a big impact on yields.

A paper presented at this year’s Advanced Semiconductor Manufacturing Conference describes how one facility has driven down defect densities through a focused equipment maintenance improvement program. IBM’s Burlington, VT, fab began the program in early 2002 to reduce foreign-material defects. Formed around each key toolset, teams are made up of process and equipment engineering, manufacturing, and maintenance personnel.

Each team uses a basic methodology to accomplish the mission, meeting regularly to review tool data and craft action plans to reduce defects. One key metric is a graph depicting the toolset’s weekly defect mean value with a high/low range above and below the mean. The resulting focus on the most common defect types and the worst-performing equipment allows the teams to zero in on those areas that provide the most tangible results.

After two years, the Burlington program has reduced defects by a whopping 65%, the kind of number that should get the maintenance mavens some newfound respect.