Pulsed-mode RF bias for side-wall coverage improvement
AssigneeApplied Materials, Inc.
InventorsJohn Forster, Praburam Gopalraja, Bradley O. Stimson, Liubo Hong
Life of this patent
Estimating the term…
Abstract
The present invention provides a method and apparatus for achieving conformal step coverage of one or more materials on a substrate using sputtered ionized material. A target provides a source of material to be sputtered by a plasma and then ionized by an inductive coil, thereby producing electrons and ions. In one embodiment, one or both of the signals to the substrate and the target are modulated. Preferably, the modulated signal to the substrate includes a negative voltage portion and a zero voltage portion.
Claims21
A method for controlling directionality of ionized material traveling from a target toward a substrate in a semiconductor processing system, comprising:
- providing a first partially modulated signal to a substrate positioned on a substrate support member;
- providing a second signal to the target;
- and
- providing a magnetic field in a plasma region, wherein the first partially modulated signal is modulated between a first voltage and a second voltage during a first time period, and wherein the first partially modulated signal is constant during a second time period.
A method for controlling sidewall coverage in a semiconductor deposition chamber, comprising:
- providing a first electrical signal to a substrate positioned in the deposition chamber, the electrical signal having a modulated portion and a constant portion, the modulated portion varying between a negative voltage and a slightly positive voltage;
- providing a second electrical signal to a target positioned above the substrate in the deposition chamber, the second signal being a constant DC voltage;
- and
- providing a magnetic field in the deposition chamber.
Dependencies are inferred from the claim text.