Absorptive filter for semiconductor processing systems
AssigneeNovellus Systems, Inc.
InventorStephen E. Hilliker
Life of this patent
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Abstract
In one embodiment, an absorptive filter network is provided between an RF generator and a semiconductor processing reactor. The absorptive filter network includes an absorptive filter circuit which allows energies at a fundamental frequency to pass while absorbing energies at frequencies away from the fundamental frequency. An absorptive filter circuit is located on the reactor-side of the absorptive filter network to isolate the RF generator from the effects of the non-linear loading presented by a plasma in the reactor. Another absorptive filter circuit is located on the RF generator-side of the absorptive filter network to present a stable voltage waveform to the plasma.
Claims12
A semiconductor processing system having an RF generator, a matching network coupled to a reactor, and a filter network coupled between the RF generator and the matching network, wherein the filter network comprises:
- a first parallel resonant circuit coupled between a first end coupled to the RF generator and a second end coupled to the matching network;
- a capacitor coupled between the RF generator and the matching network, the capacitor forming a series resonant circuit with the first parallel resonant circuit;
- a second parallel resonant circuit coupled between the first end and a ground reference;
- and
- a first resistive element coupled between the first end and the ground reference so that radio frequency (RF) energies at frequencies away from a resonant frequency of the second parallel resonant circuit are dissipated in the first resistive element instead of being delivered to the reactor.
A semiconductor processing system having an RF generator, a matching network coupled to a reactor, and a filter network coupled between the RF generator and the matching network, wherein the filter network comprises:
- a first parallel resonant circuit coupled between a first end coupled to the RF generator and a second end coupled to the matching network;
- a capacitor coupled between the RF generator and the matching network, the capacitor forming a series resonant circuit with the first parallel resonant circuit;
- a second parallel resonant circuit coupled between the second end and a ground reference;
- and
- a first resistive element coupled between the second end and the ground reference so that radio frequency (RF) energies at frequencies away from a resonant frequency of the second parallel resonant circuit are dissipated in the first resistive element instead of being delivered to the RF generator.
Dependencies are inferred from the claim text.