CONDITIONING: RE-CONDITIONING AFTER PREVENTIVE MAINTENANCE
Plasma chambers need preventive maintenance (PM) at regular
intervals due to:
- Films build-up from the deposition process or by-products
and resist mask fragments
- different life time of spare parts
- Erosion of surface anodization
- Exchange of end point detector quartz window and view port
Installing refurbished or new chamber parts result
in process changes.
of wafers needed for conditioning is mostly determined empirically, and
often too many wafers and time are used for the
tool is not able to detect the conditioning status.
rate is very sensitive to the chemistry at the chamber wall and can be
used as a status indicator when conditioning is complete.
layer systems and processes require a series of conditioning
wafers such as:
Using incorrect wafer types (e.g., blamk Silicon) can reserve the
conditioning process. These de-conditioning effects can not be
detected by tool parameters. It requires a chemical
such as the electron collision rate.
- Structured conditioning wafers
Insufficient conditioning can lead to process instabilities and yield
Using the electron collision rate and electron
the conditioning procedure, and increases tool uptime and OEE
(Overall Equipment Effectiveness). Once the plasma parameters
stable, chamber conditioning is complete. This enables dynamic
The electron collision rate and electron density can also used to
determine the sucess of other maintenance procedures.