This standard was technically approved by the global Physical Interfaces & Carriers Committee. This edition was approved for publication by the global Audits & Reviews Subcommittee on April 30, 2010. Initially available at www.semi.org in June 2010. Originally published in 1992; previously published July 2004.

NOTICE: This document was balloted and approved for withdrawal in 2010.

The purpose of this standard is to prevent any opening or closing of the isolation valve(s) which would result in an unsafe condition or possible damage to material or equipment.

SEMI E21 — Cluster Tool Module Interface: Mechanical Interface and Wafer Transport Standard