International SEMATECH Manufacturing Initiative (ISMI) has released its reliability, availability and maintainability calculator (RAMCalc), a Web-based application that captures and calculates RAM metrics, at the equipment, module and wafer levels, for SEMI E10-conformant reporting. ISMI’s RAMCalc enables equipment, industrial and maintenance engineers to calculate RAM metrics such as mean time between failures, mean time to repair, mean time off line, and availability for single-path and complex multi-path cluster tools.

The basic single-path RAMCalc, which is available to the public free of charge, calculates performance of single chamber or non-clustered manufacturing equipment. In addition to the single-path calculator, a multi-path version of RAMCalc enables tracking of complex multi-path cluster tool equipment.

“The development of a robust data collection solution for equipment demonstration testing is critical,” said Lorn Christal, ISMI project manager. “ISMI’s role in an equipment demonstration test is to deliver accurate performance metrics formulated from standardized data collection mechanisms.”

Algorithms used in RAMCalc can be loaded independently on fab tools to automatically generate RAM metrics consistent with SEMI E10. According to Jo Beekman, co-project manager, “RAMCalc is flexible. It currently generates metrics consistent with SEMI E10, but using a different set of states it can be adapted to other metrics such as those related to equipment productivity, or it can be used to generate metrics for states that have yet to be defined.”

SEMI E10 is a well-known industry standard for measuring equipment reliability performance of semiconductor manufacturing equipment. SEMI E10 establishes a common basis for communication between users and suppliers of semiconductor equipment by providing standards for measuring RAM performance of that equipment in a manufacturing environment. A ballot to revise the SEMI E10 Standard is expected later this year. The ballot will attempt to formalize the calculation of RAM metrics for multi-path cluster tool equipment. ISMI’s RAMCalc is designed to conform to the emerging ballot.

RAMCalc source code is available via ISMI's Collaborative Application Development Environment (CADe). CADe is a “community source” code sharing program that is available at no charge to ISMI members, and on a quid pro quo basis to non-member companies.

ISMI will provide an introduction on the use of RAMCalc to track or benchmark equipment performance in situations involving marathon tests and high volume production environments at the ISMI Symposium on November 1, 2010. The course will highlight new concepts: intended process sets, single path cluster tools and multi-path cluster tools, and demonstrate how RAMCalc can be used in each of these situations.

The basic RAMCalc application is available on ISMI’s public web site at For more information, contact Johannes Beekman,, or Lorn Christal,

About ISMI
ISMI is a global alliance of the world’s major semiconductor manufacturers, dedicated to reducing cost per wafer and ultimately cost per die, through cooperative programs focused on manufacturing effectiveness. ISMI is a wholly-owned subsidiary of SEMATECH,