Etch chambers, toxic gas and RF — isolation with a hazard on every line.
A wet clean on an etch chamber is a lockout on electrical, RF, process gas, vacuum, chilled water, and the toxic-gas cabinet feeding the tool. Several of those have their own interlocks, and the fab's gas system has its own isolation discipline that the LOTO procedure has to sit inside, not replace.
The tool vendor's service procedure and the fab's energy-control procedure are two documents. The gap between them is where the finding lives.
Fabs run 24/7 with contractors on tools constantly. Who is qualified on which tool, and whether their qualification is current, is a question the record has to answer before a lock goes on — not after an incident.
The electrical isolation is complete; the gas cabinet upstream is still supplying because it belongs to facilities, not the tool owner, and the procedure stopped at the tool boundary.
A contractor applies a lock on a tool they were qualified on eighteen months ago. Nothing checked.
The valve is closed and locked; the loop between the valve and the chamber was never bled.
Real isolation-point structure, illustrative tags, equipment that does not exist. Free to read and download. An example to learn from — not a document to adopt.
Full energy isolation of plasma etch chamber A for scheduled chamber wet clean. Cl2/BCl3 metal etch chemistry.
- 10 isolation points
The system checks the applying person's current qualification on the curriculum the procedure requires, and refuses the lock if it is missing or expired. The refusal is recorded.
A bleed point can carry a required dwell; the next step is not offered until it has elapsed.
Vendor engineers are users of the site, with the same training gate as employees. Users are unlimited.
Plans are per site, per year, unlimited users — see pricing.