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US 6,855,209 B2Granted
Plasma chamber cleaning
AssigneeScientific Systems Research Limited
InventorsJohn Scanlan, Kevin O'Leary
Life of this patent
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Abstract
A method for determining optimum plasma chamber cleaning cycles based on an electrical precursor signal. Polymer build up on the interior wall of plasma chamber 1 during normal production runs is monitored by observing the phase of the fundamental RF signal on a pre-selected baseline process. At a predetermined level of this signal, the chamber processing is stopped and the chamber walls are cleaned.
Claims8
A method of motivating flaking events by determining a cleaning interval for interior walls of an RF-powered plasma processing chamber subject to unwanted material-build-up, the method comprising:
- (a) after cleaning the walls, running a given baseline plasma process on the chamber and determining a corresponding magnitude of a characteristic of delivered RF power at a fundamental frequency;
- (b) repeating step (a) at intervals between production runs;
- and
- (c) cleaning the walls at a time which is a function of the said magnitude.
1 more element
Dependencies are inferred from the claim text.