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US5468296A Expired / Lapsed US ⏱️ 0.0 years remaining

Apparatus for igniting low pressure inductively coupled plasma

Assignee: LSI Corp
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Filing: 1993-12-17
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Granted: 1995-11-21
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Expires: 2013-12-17
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Abstract

Abstract An apparatus for producing a plasma suitable for semiconductor processing at pressures in the low millitorr range. The apparatus includes a vacuum chamber with a dielectric window, a generally planar coil disposed adjacent the window outside the chamber and coupled to an appropriate power source, and a plasma initiator disposed within the chamber. Once the plasma is initiated, the planar coil sustains the plasma by inductive power coupling. In one embodiment the plasma initiator is a secondary electrode disposed within the chamber and coupled to a second RF power source. In an alternative embodiment both the secondary electrode and a target pedestal are coupled to the secondary RE power source through a power splitter. In an alternative embodiment, the plasma initiator is used to ionize a portion of the process gas and provide a plasma that may then inductively couple with the planar coil. Initial ionization of the process gas may be achieved by use of an ultraviolet light source, an ultraviolet laser, a high voltage power source such as a tesla coil, or an electrical arc forming device such as a spark plug.

Inventors

  • 👤 Roger Patrick
  • 👤 Philippe Schoenborn
  • 👤 Mark Franklin
  • 👤 Frank Bose

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 17:54
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/32009; H01J37/32082; H01J37/321; C; C23; C23C; C23C16/00; C23C16/44; C23C16/50; C23C16/505; C23C16/507

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 156 words
A plasma generation apparatus, comprising: a vacuum chamber, including a gas inlet, a vacuum outlet, and an aperture; a dielectric window disposed in the aperture and forming a substantially vacuum seal with the container; a substantially planar coil disposed outside the vacuum chamber adjacent the window; starter means for initiating a plasma discharge within the vacuum chamber at pressures in the low 5 millitorr range, wherein a plasma discharge within the chamber is initiated by said starter means and then maintained by energy provided to the plasma from the substantially planar coil; wherein said starter means includes an electrode disposed within the chamber and electrically coupled to an external power source, wherein a plasma discharge within the chamber is initiated at low pressures; a target pedestal disposed within the chamber and electrically coupled to said external power source; and an RF power splitter between the external power source, the target pedestal and the starter means electrode.
Claim 2
Dependent Claim 156 words
A plasma generation apparatus, comprising: a vacuum chamber, including a gas inlet, a vacuum outlet, and an aperture; a dielectric window disposed in the aperture and forming a substantially vacuum seal with the container; a substantially planar coil disposed outside the vacuum chamber adjacent the window; starter means for initiating a plasma discharge within the vacuum chamber at pressures in the low 5 millitorr range, wherein a plasma discharge within the chamber is initiated by said starter means and then maintained by energy provided to the plasma from the substantially planar coil; wherein said starter means includes an electrode disposed within the chamber and electrically coupled to an external power source, wherein a plasma discharge within the chamber is initiated at low pressures; a target pedestal disposed within the chamber and electrically coupled to said external power source; and an RF power splitter between the external power source, the target pedestal and the starter means electrode.
Claim 3
Dependent Claim 27 words
The plasma generation apparatus of claim 1 further including a phase delay between the power splitter and either of the starter means electrode and the target pedestal.
Claim 4
Dependent Claim 148 words
A plasma generation apparatus, comprising: a vacuum chamber, including a gas inlet, a vacuum outlet, and an aperture; a dielectric window disposed in the aperture and forming a substantially vacuum seal with the container; a substantially planar coil disposed outside the vacuum chamber adjacent the window; starter means for initiating a plasma discharge within the vacuum chamber at pressures in the low 5 millitorr range, wherein a plasma discharge within the chamber is initiated by said starter means and then maintained by energy provided to the plasma from the substantially planar coil; wherein said starter means includes ionizing means for partially ionizing a process gas with the container, wherein the plasma is subsequently sustained within the chamber by inductive coupling to the substantially planar coil; and wherein said ionizing means is a tesla coil including an output rod projecting into the chamber and electrically insulated from the chamber.
Claim 5
Dependent Claim 148 words
A plasma generation apparatus, comprising: a vacuum chamber, including a gas inlet, a vacuum outlet, and an aperture; a dielectric window disposed in the aperture and forming a substantially vacuum seal with the container; a substantially planar coil disposed outside the vacuum chamber adjacent the window; starter means for initiating a plasma discharge within the vacuum chamber at pressures in the low 5 millitorr range, wherein a plasma discharge within the chamber is initiated by said starter means and then maintained by energy provided to the plasma from the substantially planar coil; wherein said starter means includes ionizing means for partially ionizing a process gas with the container, wherein the plasma is subsequently sustained within the chamber by inductive coupling to the substantially planar coil; and wherein said ionizing means is a tesla coil including an output rod projecting into the chamber and electrically insulated from the chamber.
Claim 6
Dependent Claim 138 words
A plasma generation apparatus, comprising: a vacuum chamber, including a gas inlet, a vacuum outlet, and an aperture; a dielectric window disposed in the aperture and forming a substantially vacuum seal with the container; a substantially planar coil disposed outside the vacuum chamber adjacent the window; starter means for initiating a plasma discharge within the vacuum chamber at pressures in the low 5 millitorr range, wherein a plasma discharge within the chamber is initiated by said starter means and then maintained by energy provided to the plasma from the substantially planar coil; wherein said starter means includes ionizing means for partially ionizing a process gas with the container, wherein the plasma is subsequently sustained within the chamber by inductive coupling to the substantially planar coil; and wherein said ionizing means is a spark plug disposed within the chamber.
Claim 7
Dependent Claim 138 words
A plasma generation apparatus, comprising: a vacuum chamber, including a gas inlet, a vacuum outlet, and an aperture; a dielectric window disposed in the aperture and forming a substantially vacuum seal with the container; a substantially planar coil disposed outside the vacuum chamber adjacent the window; starter means for initiating a plasma discharge within the vacuum chamber at pressures in the low 5 millitorr range, wherein a plasma discharge within the chamber is initiated by said starter means and then maintained by energy provided to the plasma from the substantially planar coil; wherein said starter means includes ionizing means for partially ionizing a process gas with the container, wherein the plasma is subsequently sustained within the chamber by inductive coupling to the substantially planar coil; and wherein said ionizing means is a spark plug disposed within the chamber.
Claim 8
Independent Claim 144 words
An apparatus for treating semiconductor wafers with a plasma comprising: a chamber including a gas inlet, a vacuum exhaust, and a dielectric window; a substantially planar coil disposed adjacent to and substantially oriented parallel with said dielectric window; a first power source coupled to said substantially planar coil; a secondary electrode disposed within the chamber; a second power source electrically connected to said second electrode, wherein plasma is initiated within the chamber by coupling between said secondary electrode and a process gas, and subsequently maintained by coupling between the process gas and the substantially planar coil; a target pedestal disposed within the chamber and coupled to said second power source; and an RF power splitter between the and power source, the secondary electrode and the target pedestal, and a phase delay between the power splitter and either of the electrode and the target pedestal.
Claim 9
Independent Claim 144 words
An apparatus for treating semiconductor wafers with a plasma comprising: a chamber including a gas inlet, a vacuum exhaust, and a dielectric window; a substantially planar coil disposed adjacent to and substantially oriented parallel with said dielectric window; a first power source coupled to said substantially planar coil; a secondary electrode disposed within the chamber; a second power source electrically connected to said second electrode, wherein plasma is initiated within the chamber by coupling between said secondary electrode and a process gas, and subsequently maintained by coupling between the process gas and the substantially planar coil; a target pedestal disposed within the chamber and coupled to said second power source; and an RF power splitter between the and power source, the secondary electrode and the target pedestal, and a phase delay between the power splitter and either of the electrode and the target pedestal.
Claim 10
Dependent Claim 111 words
A plasma generator for semiconductor processing, comprising: a vacuum chamber including a gas inlet, an exhaust outlet, and a dielectric window; a substantially planar coil disposed adjacent to and oriented substantially parallel with said dielectric window; a first power source coupled to said substantially planar coil; and ionizing means for ionizing some of a process gas within the chamber, wherein a plasma is initiated within the chamber by ionization of a portion of said process gas and maintained by inductive coupling between the plasma and the substantially planar coil; wherein said ionizing means is a tesla coil including an output rod projecting into the chamber and electrically insulated from the chamber.
Claim 11
Dependent Claim 111 words
A plasma generator for semiconductor processing, comprising: a vacuum chamber including a gas inlet, an exhaust outlet, and a dielectric window; a substantially planar coil disposed adjacent to and oriented substantially parallel with said dielectric window; a first power source coupled to said substantially planar coil; and ionizing means for ionizing some of a process gas within the chamber, wherein a plasma is initiated within the chamber by ionization of a portion of said process gas and maintained by inductive coupling between the plasma and the substantially planar coil; wherein said ionizing means is a tesla coil including an output rod projecting into the chamber and electrically insulated from the chamber.
Claim 12
Dependent Claim 101 words
A plasma generator for semiconductor processing, comprising: a vacuum chamber including a gas inlet, an exhaust outlet, and a dielectric window; a substantially planar coil disposed adjacent to and oriented substantially parallel with said dielectric window; a first power source coupled to said substantially planar coil; and ionizing means for ionizing some of a process gas within the chamber, wherein a plasma is initiated within the chamber by ionization of a portion of said process gas and maintained by inductive coupling between the plasma and the substantially planar coil; wherein said ionizing means is a spark plug disposed within the chamber.
Claim 13
Dependent Claim 101 words
A plasma generator for semiconductor processing, comprising: a vacuum chamber including a gas inlet, an exhaust outlet, and a dielectric window; a substantially planar coil disposed adjacent to and oriented substantially parallel with said dielectric window; a first power source coupled to said substantially planar coil; and ionizing means for ionizing some of a process gas within the chamber, wherein a plasma is initiated within the chamber by ionization of a portion of said process gas and maintained by inductive coupling between the plasma and the substantially planar coil; wherein said ionizing means is a spark plug disposed within the chamber.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-11-20 1999-05-22 1999-11-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-11-20 2003-05-22 2003-11-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-11-20 2007-05-22 2007-11-21 $7700.00 Window Closed / Lapsed

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