Multi-Point Monitoring In Minienvironments

By Morgan Polen, VP of Application Technology, Lighthouse Worldwide Solutions

Minienvironments and isolation technology have become commonplace in semiconductor and other high technology manufacturing industries. The use of minienvironments and the associated automation allows for greater levels of control as well as improved process cleanliness. 

Minienvironments come in many sizes and shapes. Traditional minienvironments were built around the process tool after the tool was installed. Modern minienvironments are integrated as part of the process equipment. Design of the tool, airflow patterns and pressurization are important considerations in maintaining the cleanliness classification at which the tool is designed to operate.

The use of particle counters to monitor, test and characterize minienvironments has been an established practice in cleanroom manufacturing. The particle counter is used in conjunction with other equipment such as pressure differential indicators, air velocity sensors, and temperature/relative humidity probes. A traditional portable particle counter is often deployed as the main tool to accomplish the testing, characterization and fine-tuning process .This generally is the same particle counter used to test and monitor the main cleanroom. Characterization is required to assure the tool is performing to the required cleanliness. Routine monitoring is also needed as an audit to assure that nothing has changed.