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US4190786A Expired / Lapsed US ⏱️ 0.0 years remaining

Discharge lamp

Assignee: Ushio Denki KK
•
Filing: 1978-03-29
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Granted: 1980-02-26
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Expires: 1998-03-29
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Abstract

Abstract A discharge lamp of the type which seals mercury and a rare gas in a bulb having sealed therein a pair of electrodes and in which both the mercury and the rare gas contribute to discharge radiation. Letting the value of the quantity of mercury (mg/cc.) sealed per 1 cc. of the volume of the bulb and the value of the (atmospheric) pressure of the rare gas be represented by X and Y, respectively, the values X and Y are selected to be in the ranges of 1≦X≦13 and 2≦Y≦10, respectively, whereby to abundantly emit ultraviolet rays of the wavelengths between 2000 to 2500 A. The discharge lamp is employed as a light source for photolithography in the manufacture of semiconductor devices to achieve the formation of a fine pattern in a short time.

Inventors

  • 👤 Takehiro Kira

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 03:37
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70008; G03F7/70016; H; H01; H01J; H01J61/00; H01J61/02; H01J61/12; H01J61/18; H01J61/20

Claims Analysis

Total Claims: 32
Claim 1
Independent Claim 71 words
A source of ultraviolet radiation comprising: a sealed bulb, at least a portion of said bulb being transmitting to wavelengths below 3000 angstroms, a pair of electrodes sealed in said bulb, mercury sealed within said bulb in amount from 1 to 13 mg. per cc. of volume of said bulb, and at least one rare gas sealed within said bulb at a pressure from 2 to 10 atm. at 25° C.
Claim 2
Dependent Claim 71 words
A source of ultraviolet radiation comprising: a sealed bulb, at least a portion of said bulb being transmitting to wavelengths below 3000 angstroms, a pair of electrodes sealed in said bulb, mercury sealed within said bulb in amount from 1 to 13 mg. per cc. of volume of said bulb, and at least one rare gas sealed within said bulb at a pressure from 2 to 10 atm. at 25° C.
Claim 3
Dependent Claim 16 words
The source of claim 1, said portion of said bulb transmitting between 2000 and 2500 angstroms.
Claim 4
Dependent Claim 20 words
The source of claim 1, said electrodes comprising an anode and a cathode for operating said source with DC voltage.
Claim 5
Dependent Claim 44 words
The source of claim 3, said bulb having length L in a vertical direction, said anode and cathode being aligned vertically from above and below, respectively, and said anode being located between the center of said bulb and a distance L/6 below said center.
Claim 6
Dependent Claim 30 words
The source of claim 1 or 4, wherein said amounts of mercury and rare gas are adjusted to maximize the emission of said ultraviolet radiation between 2000 and 2500 angstroms.
Claim 7
Dependent Claim 15 words
The source of claim 1 or 4, said at least one rare gas comprising xenon.
Claim 8
Dependent Claim 29 words
The source of claim 4, said anode comprising a volume in the range from 0.5×10 -3 to 1.5×10 -3 cc. per watt of rated power dissipation of said source.
Claim 9
Dependent Claim 47 words
The source of claim 7 comprising means for operating said bulb for exposing photoresist in practical exposure periods of considerably less than 100 sec., said at least one rare gas comprising xenon, and said at least one portion of said bulb transmitting between 2000 and 2500 angstroms.
Claim 10
Dependent Claim 32 words
The source of claim 4 comprising a reflective coating on the inside of said bulb from the bottom of said bulb to a distance L/6 from said bottom in said vertical direction.
Claim 11
Dependent Claim 27 words
The source of claim 3, said anode and cathode being selectively spaced to comprise a lamp chosen from the group consisting of short and long arc lamps.
Claim 12
Independent Claim 81 words
A method for producing ultraviolet radiation below 3000 angstroms comprising: providing a lamp having a bulb that transmits said ultraviolet radiation, a pair of electrodes sealed in said bulb, and mercury in amount from 1 to 13 mg. per cc. of bulb volume and at least one rare gas at a pressure from 2 to 10 atm. at 25° C. sealed in said bulb, and operating said lamp by applying a voltage across said electrodes sufficient to produce said ultraviolet radiation.
Claim 13
Independent Claim 81 words
A method for producing ultraviolet radiation below 3000 angstroms comprising: providing a lamp having a bulb that transmits said ultraviolet radiation, a pair of electrodes sealed in said bulb, and mercury in amount from 1 to 13 mg. per cc. of bulb volume and at least one rare gas at a pressure from 2 to 10 atm. at 25° C. sealed in said bulb, and operating said lamp by applying a voltage across said electrodes sufficient to produce said ultraviolet radiation.
Claim 14
Dependent Claim 16 words
The method of claim 11, said bulb transmitting said ultraviolet radiation between 2000 and 2500 angstroms.
Claim 15
Dependent Claim 22 words
The method of claim 11, said pair of electrodes comprising an anode and a cathode for operating said lamp with DC voltage.
Claim 16
Dependent Claim 44 words
The method of claim 13, said bulb having length L in a vertical direction, said anode and cathode being aligned vertically from above and below, respectively, and said anode being located between the center of said bulb and a distance L/6 below said center.
Claim 17
Dependent Claim 27 words
The method of claim 11, comprising adjusting said amounts of mercury and rare gas to maximize the emission of said ultraviolet radiation between 2000 and 2500 angstroms.
Claim 18
Dependent Claim 15 words
The method of claim 11 or 14, said at lease one rare gas comprising xenon.
Claim 19
Dependent Claim 29 words
The method of claim 13, said anode comprising a volume in the range from 0.5×10 -3 to 1.5×10 -3 cc. per watt of rated power dissipation of said lamp.
Claim 20
Dependent Claim 35 words
The method of claim 14, said lamp comprising a reflective coating on the inside of said bulb from the bottom of said bulb to a distance in said vertical direction of L/6 from said bottom.
Claim 21
Dependent Claim 27 words
The method of claim 13, said anode and cathode being selectively spaced to comprise a lamp chosen from the group consisting of short and long arc lamps.
Claim 22
Dependent Claim 70 words
An improved source of ultraviolet radiation, said source comprising a sealed bulb transmitting wavelengths as low as 2000 angstroms and a pair of electrodes sealed in said bulb, said improvement comprising mercury sealed in said bulb in amount from 1 to 13 mg. per cc. of said bulb volume, and at least one rare gas sealed within said bulb at a pressure from 2 to 10 atm. at 25° C.
Claim 23
Dependent Claim 70 words
An improved source of ultraviolet radiation, said source comprising a sealed bulb transmitting wavelengths as low as 2000 angstroms and a pair of electrodes sealed in said bulb, said improvement comprising mercury sealed in said bulb in amount from 1 to 13 mg. per cc. of said bulb volume, and at least one rare gas sealed within said bulb at a pressure from 2 to 10 atm. at 25° C.
Claim 24
Dependent Claim 14 words
The improved source of claim 20, said bulb transmitting between 2000 and 3000 angstroms.
Claim 25
Dependent Claim 24 words
The improved source of claim 21, said pair of electrodes comprising an anode and a cathode, and said lamp being operated with DC voltage.
Claim 26
Dependent Claim 48 words
The improved source of claim 22, said improvement comprising said bulb having length L in a vertical direction, said anode and cathode being aligned vertically from above and below, respectively, and said anode being located between the center of said bulb and a distance L/6 below said center.
Claim 27
Dependent Claim 25 words
The improved source of claim 21, said improvement comprising adjusting said mercury and rare gas(es) to maximize said ultraviolet radiation between 2000 and 2500 angstroms.
Claim 28
Dependent Claim 17 words
The improved source of claim 20, said improvement comprising said at least one rare gas comprising xenon.
Claim 29
Dependent Claim 30 words
The improved source of claim 22, said improvement comprising a volume in the range from 0.5×10 -3 to 1.5×10 -3 cc. per watt of rated power dissipation of said source.
Claim 30
Dependent Claim 35 words
The improved source of claim 23, said improvement comprising a reflective coating on the inside of said bulb from the bottom of said bulb to a distance L/6 from said bottom in said vertical direction.
Claim 31
Dependent Claim 28 words
The improved source of claim 22, said anode and cathode being selectively spaced to comprise a lamp chosen from the group consisting of short and long arc lamps.
Claim 32
Dependent Claim 39 words
The improved source of claim 20 or 26, said sealed bulb, electrodes, mercury and at least one rare gas providing said transmitted wavelengths with sufficient intensity for exposing photoresist in practical exposure times of considerably less than 100 sec.

References Cited (Backward Citations)

US2707247A Cited
US2896107A Cited
US2990490A Cited
US3786297A Cited
US4038578A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1983-02-25 1983-08-27 1984-02-26 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1987-02-25 1987-08-27 1988-02-26 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1991-02-25 1991-08-27 1992-02-26 $7700.00 Window Closed / Lapsed

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