US5707486A — Plasma reactor using UHF/VHF and RF triode source…

Claim 1

Independent Claim 184 words

A system for processing a workpiece comprising: a vacuum processing chamber for the workpiece; a chamber inlet for introducing process gas into the chamber; a plurality of electrodes coupling AC electrical energy into the chamber to generate a plasma in the gas, the electrodes comprising a first electrode structure having two separate sections for defining a plasma-generating electrical field, the field being concentrated within a region of the chamber spaced from the workpiece, the field also being principally oriented parallel to the workpiece for preventing ion acceleration from or toward the workpiece, and a second electrode structure adapted to support the workpiece and for modifying a sheath voltage associated with the electrodes and plasma ion energy proximate the workpiece; first source of AC electrical energy to the first electrode at a first frequency within the range of about 50 MHz to about 800 MHz, and a second source of AC electrical energy to the second electrode at a second frequency within the range of about 0.1 MHz up to but below about 50 MHz, thereby controlling the sheath voltage and the plasma ion energy.

Claim 2

Independent Claim 184 words

A system for processing a workpiece comprising: a vacuum processing chamber for the workpiece; a chamber inlet for introducing process gas into the chamber; a plurality of electrodes coupling AC electrical energy into the chamber to generate a plasma in the gas, the electrodes comprising a first electrode structure having two separate sections for defining a plasma-generating electrical field, the field being concentrated within a region of the chamber spaced from the workpiece, the field also being principally oriented parallel to the workpiece for preventing ion acceleration from or toward the workpiece, and a second electrode structure adapted to support the workpiece and for modifying a sheath voltage associated with the electrodes and plasma ion energy proximate the workpiece; first source of AC electrical energy to the first electrode at a first frequency within the range of about 50 MHz to about 800 MHz, and a second source of AC electrical energy to the second electrode at a second frequency within the range of about 0.1 MHz up to but below about 50 MHz, thereby controlling the sheath voltage and the plasma ion energy.

Claim 3

Dependent Claim 78 words

The system of claim 1, wherein: the chamber includes a dielectric dome internally defining a section of the chamber; the first electrode structure surrounds the chamber section defined within the dome; the second electrode structure has a planar surface proximate and parallel to the workpiece; and the first electrode structure and the second electrode structure are positioned for forming an electric field in the chamber parallel to and spaced from the planar surface of the second electrode structure.

Claim 4

Dependent Claim 29 words

The system of claim 2, wherein the first electrode structure is located on the interior of the dielectric dome and is covered on the inside of the dielectric dome.

Claim 5

Independent Claim 18 words

The system of 2, wherein the first electrode structure is formed on the exterior of the dielectric dome.

Claim 6

Independent Claim 18 words

The system of 2, wherein the first electrode structure is formed on the exterior of the dielectric dome.

Claim 7

Dependent Claim 46 words

The system of claim 1, wherein the first electrode structure comprises a split electrode, the system further comprising means for feeding the gas within the chamber from proximate the chamber inlet to proximate the workpiece for transporting components of the plasma into contact with the workpiece.

Claim 8

Dependent Claim 75 words

The system of claim 5, wherein the chamber comprises an exhaust port for evacuating the chamber; and wherein said chamber inlet comprises: said exhaust port which is located opposite the workpiece from the split electrode; and a plurality of gas inlet ports for admitting the gas into the chamber, the inlet ports being spaced about the chamber proximate the split electrode for producing gas flow toward the workpiece from the selected region of the chamber.

Claim 9

Dependent Claim 17 words

The system of claim 5, wherein the split electrode comprises a pair of approximately semicircular ring members.

Claim 10

Dependent Claim 29 words

The system of claim 7, wherein the ring members concentrically enclose the chamber for concentrating the electric field within a right circular cylinder that is perpendicular to the workpiece.

Claim 11

Dependent Claim 58 words

The system of claim 1, wherein said chamber comprises a first chamber including said first electrode structure and a second chamber including said second electrode structure and having a central opening in a wall thereof, side walls of said first chamber substantially extending to said central opening, whereby said first chamber substantially uninterruptibly communicates with said second chamber.

Claim 12

Independent Claim 193 words

A system for processing a workpiece in a plasma generated from a gas, comprising: a vacuum processing chamber for receiving the gas; a support electrode for supporting the workpiece within the chamber; a split electrode surrounding a volume of the chamber in parallel spaced relation to the workpiece for capacitively coupling AC electrical energy into the chamber to produce a plasma-inducing electrical field in a selected region of the chamber spaced from the support electrode, to prevent damage to the workpiece, and a first power supply connected to the split electrode for supplying high frequency AC energy having a frequency in the range of 50-800 MHz to the split electrode and for controlling the power of the energy, to provide selected plasma density and plasma ion current density; and a second power supply for applying to the support electrode selected AC electrical energy of lower frequency, in the range 0.1 MHz up to but below 50 MHz, than said capacitively coupled AC electrical energy, and for controlling said selected AC electrical energy applied to the support electrode to control a plasma sheath voltage at the support electrode and an associated plasma ion energy.

Claim 13

Independent Claim 193 words

A system for processing a workpiece in a plasma generated from a gas, comprising: a vacuum processing chamber for receiving the gas; a support electrode for supporting the workpiece within the chamber; a split electrode surrounding a volume of the chamber in parallel spaced relation to the workpiece for capacitively coupling AC electrical energy into the chamber to produce a plasma-inducing electrical field in a selected region of the chamber spaced from the support electrode, to prevent damage to the workpiece, and a first power supply connected to the split electrode for supplying high frequency AC energy having a frequency in the range of 50-800 MHz to the split electrode and for controlling the power of the energy, to provide selected plasma density and plasma ion current density; and a second power supply for applying to the support electrode selected AC electrical energy of lower frequency, in the range 0.1 MHz up to but below 50 MHz, than said capacitively coupled AC electrical energy, and for controlling said selected AC electrical energy applied to the support electrode to control a plasma sheath voltage at the support electrode and an associated plasma ion energy.

Claim 14

Dependent Claim 43 words

The system of claim 10, further comprising means for applying to the chamber a magnetic field oriented non-orthogonal to the electric field and transverse to the support electrode, for controlling the location of the plasma and extending the plasma downstream to the workpiece.

Claim 15

Dependent Claim 35 words

The system of claim 10, further comprising means for feeding the gas within the chamber from proximate the selected region to proximate the workpiece for transporting components of the plasma into contact with the workpiece.

Claim 16

Dependent Claim 78 words

The system of claim 12, wherein the chamber comprises an exhaust port for evacuating the chamber, and wherein the means for feeding the gas comprises: said exhaust port which is located opposite the workpiece from the split electrode; and a plurality of gas inlet ports for admitting the gas into the chamber, the inlet ports being spaced about the chamber proximate the dielectric dome for producing gas flow toward the workpiece from the selected regions of the chamber.

Claim 17

Dependent Claim 21 words

A system for processing a workpiece according to claim 10 wherein said chamber includes a dielectric dome inside the split electrode.

Claim 18

Dependent Claim 117 words

A process for generating a plasma, comprising: supporting a workpiece on a supporting electrode within a vacuum chamber; supplying gas to the vacuum chamber; using a surrounding electrode structure having two separate sections surrounding a volume of the vacuum chamber in relation to the workpiece, capacitively coupling electrical energy at a first frequency of from 50-800 MHz into the chamber for generating a plasma from the gas for processing one or more materials on the workpiece; and controlling the power of the first frequency electrical energy; applying RF energy to the supporting electrode at a second frequency of 0.1 up to but below 50 Mhz; and controlling a power of the RF energy at said second frequency.

Claim 19

Dependent Claim 117 words

A process for generating a plasma, comprising: supporting a workpiece on a supporting electrode within a vacuum chamber; supplying gas to the vacuum chamber; using a surrounding electrode structure having two separate sections surrounding a volume of the vacuum chamber in relation to the workpiece, capacitively coupling electrical energy at a first frequency of from 50-800 MHz into the chamber for generating a plasma from the gas for processing one or more materials on the workpiece; and controlling the power of the first frequency electrical energy; applying RF energy to the supporting electrode at a second frequency of 0.1 up to but below 50 Mhz; and controlling a power of the RF energy at said second frequency.

Claim 20

Dependent Claim 45 words

The process of claim 15, wherein a power delivered to the surrounding electrode structure defines an ion flux density and the power delivered to the supporting electrode defines a cathode sheath voltage, for directing ions and controlling ion energy independently of the ion flux density.

Claim 21

Dependent Claim 60 words

The process of claim 15, wherein the plasma is generated within a region of concentration of electrical energy at the first frequency, and wherein the step of supplying the gas to the vacuum chamber comprises the further step of feeding the gas within the chamber in a direction toward the workpiece from proximate the region of first frequency energy concentration.

Claim 22

Dependent Claim 31 words

A process for generating a plasma according to claim 15 wherein a first power source is connected to the first frequency electrical energy and is selected to control the plasma density.

Claim 23

Dependent Claim 35 words

A process for generating a plasma according to claim 15 wherein a second power source is connected to the second frequency electrical energy and is selected to control the sheath voltage at the supporting electrode.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2001-01-12	2001-07-14	2002-01-13	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2005-01-12	2005-07-14	2006-01-13	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2009-01-12	2009-07-14	2010-01-13	$7700.00	Window Closed / Lapsed

Plasma reactor using UHF/VHF and RF triode source, and process

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