Control of ion angular distribution function at wafer surface
AssigneeTokyo Electron Limited
InventorJozef Brcka
Life of this patent
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Abstract
A manufacturing method and apparatus for IC fabrication controls the ion angular distribution at the surface of a wafer with electrodes in a wafer support that produce electric fields parallel to the wafer surface without disturbing plasma parameters beyond the wafer surface. The ion angular distribution function (IADF) at the wafer surface is controlled for better feature coverage or etching. Grid structure is built into the substrate holder within the coating at the top of the holder. The grid components are electrically biased to provide electric fields that combine with the sheath field to distribute the ion incidence angles from the plasma sheath onto the wafer. The grid can be dynamically biased or phased to control uniformity of the effects.
Claims20
A semiconductor wafer plasma processing apparatus comprising:
- a plasma processing chamber;
- a substrate holder in the plasma processing chamber having a wafer supporting surface thereon and having a plurality of pairs of electrical conductors therein located below the wafer supporting surface;
- a plasma generator operative to generate in the plasma processing chamber a plasma bounded by a plasma sheath spaced from the substrate supporting surface;
- means for applying opposite and alternating potentials across the pairs of electrical conductors in the substrate holder to create an electric field parallel to the surface of a semiconductor wafer supported on the substrate holder;
- means for directing ions across the plasma sheath and through the parallel electric field onto the surface of the semiconductor wafer;
- and
- means for controlling the applied opposite and alternating potentials to affect the angular distribution of ions onto the semiconductor wafer over one or more points on the wafer supporting surface.
A semiconductor wafer plasma processing apparatus comprising:
- a plasma processing chamber;
- a substrate holder in the plasma processing chamber having a dielectric wafer supporting surface having a plurality of pairs of electrical conductors therein located below the wafer supporting surface;
- a plasma generator coupled to the plasma processing chamber and operative to generate in the plasma processing chamber a plasma bounded by a plasma sheath spaced from the substrate supporting surface;
- an alternating potential generator connected across each of the pairs of electrical conductors to produce electric fields close to and parallel to the surface of a semiconductor wafer supported on the substrate holder;
- a controller configured to control the alternating potential generator to apply different opposite and alternating potentials respectively across different pairs of electrical conductors in the substrate holder so as to affect the angular distribution of ions moving across the plasma sheath onto the semiconductor wafer over a plurality of points on the wafer supporting surface;
- and
- a bias potential generator coupled to the substrate holder to negatively bias the substrate holder relative to the plasma in the plasma processing chamber so as to cause ions from the plasma to move across the plasma sheath toward and onto the wafer supporting surface.
Dependencies are inferred from the claim text.