US4960610A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of treating semiconductor wafers in a magnetically confined plasma at low pressure by monitoring peak to peak voltage of the plasma
Assignee: CollabRx Inc
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Filing: 1989-11-13
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Granted: 1990-10-02
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Expires: 2009-11-13
Abstract
Abstract In a magnetically confined plasma, optimal pressure is found by measuring the peak to peak voltage of the plasma and looking for a distinct minimum in the peak to peak voltage. The pressure at which the minimum occurs can be used to calibrate a manometer used in the system.
Inventors
- 👤 Ole Krogh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:59
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/32917; H01J37/32935; H01J37/32431; H01J37/3244
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
61 words
In a process for treating a semiconductor wafer in a chamber containing an RF induced, magnetically confined glow discharge at a pressure below two hundred millitorr, the improvement comprising the steps of: monitoring the peak to peak voltage in said chamber; and maintaining the gas pressure within said chamber at a value corresponding approximately to the minimum peak to peak voltage
Claim 2
Dependent Claim
61 words
In a process for treating a semiconductor wafer in a chamber containing an RF induced, magnetically confined glow discharge at a pressure below two hundred millitorr, the improvement comprising the steps of: monitoring the peak to peak voltage in said chamber; and maintaining the gas pressure within said chamber at a value corresponding approximately to the minimum peak to peak voltage
Claim 3
Dependent Claim
58 words
The process as set forth in claim 1 wherein said maintaining step comprises: supplying one or more gases to said chamber at or below a predetermined flow; exhausting said chamber with a pump having a capacity greater than said predetermine flow; and regulating the exhausting of said chamber with a valve interposed between said chamber and said pump.
Claim 4
Dependent Claim
31 words
The process as set forth in claim 1 and further comprising the step of: adjusting the pressure in said chamber to an initial value by monitoring the pressure within said chamber.
Claim 5
Dependent Claim
45 words
The process as set forth in claim 1 wherein said value is retained as a reference value and further comprising the steps of: adjusting the pressure in said chamber to a value higher than said reference value, and treating said wafer at said higher value.
Claim 6
Dependent Claim
57 words
In a process for treating a semiconductor wafer in a chamber containing an RF induced, magnetically confined glow discharge at a pressure below two hundred millitorr, the improvement comprising the steps of: monitoring the ion density in said chamber; and maintaining the gas pressure within said chamber at a value corresponding approximately to the maximum ion density.
Claim 7
Dependent Claim
57 words
In a process for treating a semiconductor wafer in a chamber containing an RF induced, magnetically confined glow discharge at a pressure below two hundred millitorr, the improvement comprising the steps of: monitoring the ion density in said chamber; and maintaining the gas pressure within said chamber at a value corresponding approximately to the maximum ion density.
Claim 8
Dependent Claim
31 words
The process as set forth in claim 5 and further comprising the step of: adjusting the pressure in said chamber to an initial value by monitoring the pressure within said chamber.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-10-01 | 1994-04-02 | 1994-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-01 | 1998-04-02 | 1998-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-01 | 2002-04-02 | 2002-10-02 | $7700.00 | Window Closed / Lapsed |