US4310759A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for removal of material from the surface of a sample
Assignee: Balzers und Leybold Deutschland Holding AG
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Filing: 1980-04-10
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Granted: 1982-01-12
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Expires: 2000-04-10
Abstract
Abstract A system and method for removing material from the surface of a sample comprising: a high-frequency plasma produced in front of the sample surface; a metallic shield electrically insulated from the sample and provided with an opening determining the area to be removed, disposed between the sample and the high-frequency plasma. The parameters of this arrangement are chosen so that the relation U.sub.2 =(U.sub.1.sup.3/4 +D/C).sup.4/3 with ##EQU1## holds, wherein: U 2 =Potential difference applied between sample and plasma; D=spacing of sample surface from shield; ε O =dielectric constant of vacuum; n=density of plasma; e o =elementary charge; k=Boltzmann constant; T e =electron temperature;p0 M i =atomic mass of the species of ions (plasma ions) used; m e =electron mass; and π=3.14.
Inventors
- 👤 Hans Oechsner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:09
CPC Classifications
C; C23; C23C; C23C14/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
119 words
A system for removing material from the surface of a sample comprising: a high-frequency plasma produced in front of the sample surface; a metallic shield disposed between the sample and the high-frequency plasma, electrically insulated from the sample and provided with an aperture determining the sample area to be removed; the parameters of this arrangement are chosen so that the relation U.sub.2 =(U.sub.1.sup.3/4 +D/C).sup.4/3 with ##EQU3## holds, wherein: U 2 =Potential difference applied between sample and plasma; D=spacing of sample surface from shield; ε o =dielectric constant of vacuum; n=density of plasma; e o =elementary charge; k=Boltzmann constant; T e =electron temperature; M i =atomic mass of the species of ions (plasma ions) used; m e =electron mass; and
Claim 2
Independent Claim
119 words
A system for removing material from the surface of a sample comprising: a high-frequency plasma produced in front of the sample surface; a metallic shield disposed between the sample and the high-frequency plasma, electrically insulated from the sample and provided with an aperture determining the sample area to be removed; the parameters of this arrangement are chosen so that the relation U.sub.2 =(U.sub.1.sup.3/4 +D/C).sup.4/3 with ##EQU3## holds, wherein: U 2 =Potential difference applied between sample and plasma; D=spacing of sample surface from shield; ε o =dielectric constant of vacuum; n=density of plasma; e o =elementary charge; k=Boltzmann constant; T e =electron temperature; M i =atomic mass of the species of ions (plasma ions) used; m e =electron mass; and
Claim 3
Dependent Claim
2 words
π=3. 14.
Claim 4
Dependent Claim
2 words
π=3. 14.
Claim 5
Dependent Claim
26 words
A system according to claim 1, wherein the spacing D between the sample surface and the shield in a vacuum is adjustable in a defined manner.
Claim 6
Independent Claim
104 words
A method for removing material from the surface of a sample comprising the steps of: producing a high-frequency plasma in front of the sample surface; adjusting the spacing D between a metallic shield provided with an aperture and the sample surface in accordance with the relation U.sub.2 =(U.sub.1.sup.3/4 +D/C).sup.4/3 with ##EQU4## holds, wherein: U 2 =Potential difference applied between sample and plasma; D=spacing of sample surface from shield; ε o =dielectric constant of vacuum; n=density of plasma; e o =elementary charge; k=Boltzmann constant; T e =electron temperature; M i =atomic mass of the species of ions (plasma ions) used; m e =electron mass; and
Claim 7
Independent Claim
104 words
A method for removing material from the surface of a sample comprising the steps of: producing a high-frequency plasma in front of the sample surface; adjusting the spacing D between a metallic shield provided with an aperture and the sample surface in accordance with the relation U.sub.2 =(U.sub.1.sup.3/4 +D/C).sup.4/3 with ##EQU4## holds, wherein: U 2 =Potential difference applied between sample and plasma; D=spacing of sample surface from shield; ε o =dielectric constant of vacuum; n=density of plasma; e o =elementary charge; k=Boltzmann constant; T e =electron temperature; M i =atomic mass of the species of ions (plasma ions) used; m e =electron mass; and
Claim 8
Dependent Claim
2 words
π=3. 14.
Claim 9
Dependent Claim
2 words
π=3. 14.
References Cited (Backward Citations)
US3845305A
Cited
US3963923A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-01-11 | 1985-07-13 | 1986-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-01-11 | 1989-07-13 | 1990-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-01-11 | 1993-07-13 | 1994-01-12 | $7700.00 | Window Closed / Lapsed |