Dose monitor for plasma doping system
First Claim
1. Plasma doping apparatus comprising:
- a plasma doping chamber;
a platen mounted in said plasma doping chamber for supporting a workpiece, said workpiece constituting a cathode;
a source of ionizable gas coupled to said chamber, said ionizable gas containing a desired dopant for implantation into the workpiece;
an anode spaced from said platen;
a pulse source for applying high voltage pulses between said platen and said anode for producing a plasma having a plasma sheath in the vicinity of said workpiece, said plasma containing positive ions of said ionizable gas, said high voltage pulses accelerating said positive ions across the plasma sheath toward said platen for implantation into the workpiece; and
a Faraday cup positioned adjacent to said platen for collecting a sample of said positive ions accelerated across said plasma sheath, said sample being representative of the number of positive ions implanted into the workpiece.
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Accused Products
Abstract
Plasma doping apparatus includes a plasma doping chamber, a platen mounted in the plasma doping chamber for supporting a workpiece such as a semiconductor wafer, a source of ionizable gas coupled to the chamber, an anode spaced from the platen and a pulse source for applying high voltage pulses between the platen and the anode. The high voltage pulses produce a plasma having a plasma sheath in the vicinity of the workpiece. The high voltage pulses accelerate positive ions across the plasma sheath toward the platen for implantation into the workpiece. The plasma doping apparatus includes at least one Faraday cup positioned adjacent to the platen for collecting a sample of the positive ions accelerated across the plasma sheath. The sample is representative of the dose of positive ions implanted into the workpiece.
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Citations
40 Claims
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1. Plasma doping apparatus comprising:
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a plasma doping chamber; a platen mounted in said plasma doping chamber for supporting a workpiece, said workpiece constituting a cathode; a source of ionizable gas coupled to said chamber, said ionizable gas containing a desired dopant for implantation into the workpiece; an anode spaced from said platen; a pulse source for applying high voltage pulses between said platen and said anode for producing a plasma having a plasma sheath in the vicinity of said workpiece, said plasma containing positive ions of said ionizable gas, said high voltage pulses accelerating said positive ions across the plasma sheath toward said platen for implantation into the workpiece; and a Faraday cup positioned adjacent to said platen for collecting a sample of said positive ions accelerated across said plasma sheath, said sample being representative of the number of positive ions implanted into the workpiece. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. In plasma doping apparatus comprising a plasma doping chamber, a platen mounted in said chamber for supporting a workpiece, a source of an ionizable gas coupled to said chamber, an anode spaced from said platen and a pulse source for applying high voltage pulses between said platen and said anode for producing a plasma having a plasma sheath in the vicinity of said workpiece, said plasma containing positive ions of said ionizable gas, said high voltage pulses accelerating said positive ions across the plasma sheath toward said platen for implantation into the workpiece, a method for monitoring a dose of said positive ions implanted into the workpiece comprising the step of:
collecting a sample of said positive ions accelerated across said plasma sheath with a Faraday cup positioned adjacent to said platen, said sample being representative of a number of positive ions implanted into the workpiece. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27)
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28. Plasma doping apparatus comprising:
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a plasma doping chamber; a platen mounted in said plasma doping chamber for supporting a workpiece; a source of ionizable gas coupled to said chamber, said ionizable gas containing a desired dopant for implantation into the workpiece; a pulse source for applying high voltage pulses between said platen and the electrically conductive walls of said chamber for producing a plasma having a plasma sheath in the vicinity of said workpiece, said plasma containing positive ions of said ionizable gas, said high voltage pulses accelerating said positive ions across the plasma sheath toward said platen for implantation into the workpiece; and a Faraday cup positioned adjacent to said platen for collecting a sample of said positive ions accelerated across said plasma sheath, the sample of said positive ions collected by said Faraday cup being representative of a dose of said positive ions implanted into the workpiece. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35)
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36. Plasma doping apparatus comprising:
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a plasma doping chamber; a platen mounted in said plasma doping chamber for supporting a workpiece, said workpiece constituting a cathode; an anode spaced from said platen; a source of ionizable gas coupled to said chamber, said gas containing a desired dopant for implantation into the workpiece; means for producing a plasma containing positive ions of said ionizable gas between said platen and said anode; a pulse source for applying high voltage pulses between said platen and said anode for accelerating said positive ions across a plasma sheath of said plasma toward said platen for implantation into the workpiece; and a Faraday cup positioned adjacent to said platen for collecting a sample of said positive ions accelerated across said plasma sheath, said sample being representative of the dose of positive ions implanted into the workpiece. - View Dependent Claims (37, 38, 39, 40)
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Specification