Scanned electron cyclotron resonance plasma source
AssigneeInternational Business Machines Corporation
InventorsJohn C. Forster, William M. Holber, Joseph S. Logan
Life of this patent
Estimating the term…
Abstract
Electron cyclotron apparatus is described in which the locus of cyclotron resonance is scanned away from and toward the axis of a magnetic field by varying the strength of the magnetic field, the frequency of electromagnetic waves passing along its axis, or both.
Claims15
Electron cyclotron resonance apparatus comprising:
- a chamber,
- means for producing an axial magnetic field in said chamber that is symmetric about the axis and varies in strength with radius from the axis and decreases in strength in a given direction along the axis,
- means for passing electromagnetic waves into said axially symmetric magnetic field,
- means defining at least one opening in said chamber through which gas can be passed to a region occupied by said axially symmetric magnetic field and said electromagnetic waves, and
- scanning means for varying at least one of the strength of the axially symmetric magnetic field produced by said magnetic field producing means in an electron cyclotron resonance zone and the fundamental frequency of said electromagnetic waves so as to change the locus along which maximum cyclotron resonance occurs.
A method of producing a flow of ions to a substrate comprising the steps of:
- forming an axially symmetric D.C. magnetic field with an axis,
- projecting a beam of electromagnetic waves along the axis toward a substrate, and
- cyclically varying at least one of the strength of the axially symmetric magnetic field in an electron cyclotron resonance zone and the fundamental frequency of the electromagnetic waves so as to cause the time averaged densities of ions arriving at different parts of the substrate to be nearly the same.
Electron cyclotron resonance apparatus for producing a flow of ions toward a substrate comprising:
- means for producing an axially symmetric D.C. magnetic field having an axis,
- means for projecting electromagnetic waves along said axis,
- means for mounting a substrate in the axially symmetric magnetic field perpendicular to said axis, and
- means for varying said axially symmetric magnetic field in magnitude in an electron cyclotron resonance zone so as to make the densities of the ions arriving at different parts of said substrate more nearly the same.
Electron cyclotron resonance apparatus for producing a flow of ions toward a substrate comprising:
- means for producing an axially symmetric D.C. magnetic field having an axis,
- means for projecting electromagnetic waves along said axis,
- means for mounting a substrate in the axially symmetric magnetic field perpendicular to said axis, and
- means for varying the fundamental frequency of said electromagnetic waves so as to make the densities of the ions arriving at different parts of said substrate more nearly the same.
Electron cyclotron resonance apparatus for producing a flow of ions toward a substrate comprising:
- means for producing a D.C. magnetic field which is symmetric about an axis,
- means for projecting electromagnetic waves along said axis,
- means for mounting a substrate in the axially symmetric magnetic field transversely to said axis, and
- means for cyclically varying the fundamental frequency of the electromagnetic waves so as to make the densities of the ions arriving at different parts of the substrate more nearly the same.
Electron cyclotron resonance apparatus for producing a flow of ions toward a substrate comprising:
- means for producing a D.C. magnetic field which is symmetric about an axis,
- means for projecting electromagnetic waves along said axis,
- means for mounting a substrate in the axially symmetric magnetic field perpendicular to said axis, and
- means for cyclically varying the magnitude of the axially symmetric magnetic field in an electron cyclotron resonance zone so as to make the densities of the ions arriving at different parts of the substrate more nearly the same.
Electron cyclotron resonance apparatus comprising:
- means defining a chamber having a resonance section;
- means for introducing gas into said resonance section;
- a coil wound about said resonance section;
- means for supporting a substrate in said chamber;
- a source of electromagnetic waves;
- means for directing electromagnetic waves from said source through said resonance section;
- and
- control means for varying one of current in said coil and the fundamental frequency of said electromagnetic waves so as to change the locus of cyclotron resonance within said resonance section, whereby the locus of the maximum density of ions arriving at said substrate on said support means is radially scanned across the substrate.
Dependencies are inferred from the claim text.