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US 7,733,095 B2Granted
Apparatus for wafer level arc detection at an RF bias impedance match to the pedestal electrode
AssigneeApplied Materials, Inc.
InventorsJohn Pipitone, John C. Forster
Life of this patent
Estimating the term…
Abstract
Wafer level arc detection is provided in a plasma reactor using an RF transient sensor coupled to a threshold comparator, and a system controller responsive to the threshold comparator.
Claims20
A plasma reactor comprising:
- a chamber and a workpiece support pedestal in the chamber, the workpiece support pedestal comprising at least one electrode;
- an RF bias power generator having a first shut-off control input;
- an impedance matching circuit coupled to said at least one electrode;
- a first RF power conductor connected between said RF bias power generator and said impedance matching circuit;
- a first RF current sensor comprising:
- (a) a first ring conductor wrapped around a portion of said first RF power conductor;
- (b) a first inductive winding having a pair of ends and wrapped around a portion of said first ring conductor;
- a first arc detection comparator circuit having a first comparison threshold and having a first comparator output and having a first comparator input coupled to said first inductive winding;
- a process controller coupled to the first comparator output of said first arc detection comparator circuit and having a first process controller output coupled to said first shut-off control input of said RF bias power generator;
- a plasma RF power applicator capable of coupling RF power into said chamber;
- an RF source power generator having a second shut-off control input;
- a second impedance matching circuit coupled to said plasma RF power applicator;
- and a second RF power conductor connected between said RF source power generator and said second impedance matching circuit;
- a second RF current sensor comprising:
- (a) a second ring conductor wrapped around a portion of said second RF power conductor;
- and
- (b) a second inductive winding having a pair of ends and wrapped around a portion of said second ring conductor;
- and
- a second arc detection comparator circuit having a second comparison threshold, and having a second comparator input coupled to said second inductive winding.
16 more elements
A plasma reactor comprising:
- a chamber and a workpiece support pedestal in the chamber, the workpiece support pedestal comprising at least one electrode;
- an RF bias power generator having a first shut-off control input;
- an impedance matching circuit coupled to said at least one electrode;
- a first RF power conductor connected between said RF bias power generator and said impedance matching circuit;
- a first RF voltage sensor comprising:
- (a) a first probe conductor connected to said first RF power conductor;
- (b) a first attenuation resistor network connected to said first probe conductor;
- a first arc detection comparator circuit having a first comparison threshold and having a first comparator output and having a first comparator input coupled to said attenuation resistor network;
- a process controller coupled to the first comparator output of said first arc detection comparator circuit and having a first process controller output coupled to said shut-off control input of said RF bias power generator;
- a plasma RF power applicator capable of coupling RF power into said chamber;
- an RF source power generator having a second shut-off control input;
- a second impedance matching circuit coupled to said plasma RF power applicator;
- and a second RF power conductor connected between said RF source power generator and said second impedance matching circuit;
- a second RF voltage sensor comprising:
- (a) a second probe conductor connected to said second RF power conductor;
- (b) a second high impedance attenuation resistor network connected to said second probe conductor;
- a second arc detection comparator circuit having a second comparison threshold and coupled to said second high impedance attenuation resistor network.
14 more elements
Dependencies are inferred from the claim text.