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US4458994A Expired / Lapsed US ⏱️ 0.0 years remaining

High resolution optical lithography method and apparatus having excimer laser light source and stimulated Raman shifting

Assignee: International Business Machines Corp
•
Filing: 1983-06-07
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Granted: 1984-07-10
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Expires: 2003-06-07
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Abstract

Abstract An optical lithography method and apparatus in which a pulsed excimer laser produces at least one fundamental output which is directed to expose a photosensitive medium. The output is highly non-gaussian and has sufficient power so that full exposures can be accomplished within a few seconds. An alternate light source is provided by directing the excimer laser output to a Raman cell having a suitable Raman medium contained therein. At least one secondary wavelength is produced by stimulated Raman scattering and the output of the Raman cell is directed to expose a photosensitive medium. A mixture of more than one excimer gas can also be provided in the excimer laser to produce one fundamental output for each excimer gas present in the mixture. These outputs can be directed to expose a photosensitive medium directly. Alternatively, these outputs can be directed to a Raman cell having either a single Raman medium or multiple Raman media in a suitable mixture and directing the output from the Raman cell to expose the photosensitive medium.

Inventors

  • 👤 Kantilal Jain
  • 👤 Carlton G. Willson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 15:52
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70483; G03F7/7055; G03F7/70575; G03F7/20; G03F7/70583; H; H01; H01S; H01S3/00; H01S3/30

Claims Analysis

Total Claims: 59
Claim 1
Independent Claim 74 words
The method for exposing, in a contact or projection mode, an area of a photosensitive element to the output of a light source at a predetermined wavelength to produce a pattern, characterized in that said method comprises the steps of providing a fundamental output from a light source comprising a pulsed incoherent excimer laser; and directing the output of said excimer laser to uniformly expose said photosensitive element over the area of said pattern.
Claim 2
Independent Claim 74 words
The method for exposing, in a contact or projection mode, an area of a photosensitive element to the output of a light source at a predetermined wavelength to produce a pattern, characterized in that said method comprises the steps of providing a fundamental output from a light source comprising a pulsed incoherent excimer laser; and directing the output of said excimer laser to uniformly expose said photosensitive element over the area of said pattern.
Claim 3
Dependent Claim 32 words
The method of claim 1 further comprising the step of producing a plurality of fundamental outputs from said pulsed incoherent excimer laser, each of said fundamental outputs having a predetermined different wavelength.
Claim 4
Dependent Claim 64 words
The method of claim 1, further comprising the steps of interposing a Raman cell between the pulsed incoherent excimer laser and photosensitive element; and producing at least one secondary wavelength by stimulated Raman scattering in at least one suitable Raman medium contained in said Raman Cell, there being at least one such secondary wavelength corresponding to each Raman medium contained in said Raman cell.
Claim 5
Dependent Claim 29 words
The method of claim 3, further comprising the step of producing a plurality of secondary wavelengths by Raman scattering, each of said secondary wavelengths having a different predetermined wavelength.
Claim 6
Dependent Claim 48 words
The method of claim 3 further comprising the steps of filling said Raman cell with a plurality of suitable Raman media, and producing a plurality of secondary wavelengths by Raman scattering, one of said secondary wavelengths corresponding to each of the Raman media contained in the Raman cell.
Claim 7
Dependent Claim 58 words
The method of claim 3 further comprising the steps of producing a plurality of fundamental outputs from said pulsed incoherent excimer laser, each of said fundamental outputs having a predetermined different wavelength, and producing a plurality of secondary wavelengths from said Raman cell, there being at least one such secondary wavelength corresponding to each of the fundamental outputs.
Claim 8
Dependent Claim 51 words
The method of claim 6, further comprising the step of filling said Raman cell with a plurality of suitable Raman media, and producing a plurality of secondary wavelengths by Raman scattering, there being at least one such secondary wavelength corresponding to each of the Raman media contained in the Raman cell.
Claim 9
Independent Claim 131 words
The method for exposing, in a contact or projection mode, an area of a photosensitive element having a known wavelength sensitivity to produce a pattern comprising the steps of: providing a pulsed incoherent excimer laser; selecting an excimer medium for said excimer laser which produces a fundamental output of a predetermined wavelength; providing a Raman cell; selecting a suitable Raman medium for said Raman cell; directing the output of said pulsed incoherent excimer laser to said Raman cell to produce at least one secondary wavelength within said known wavelength sensitivity region by stimulated Raman scattering in said suitable medium contained in said Raman cell; and uniformly exposing over the area of said pattern, said photosensitive element to the output of said Raman cell to optimize exposure for said known sensitivity region.
Claim 10
Independent Claim 131 words
The method for exposing, in a contact or projection mode, an area of a photosensitive element having a known wavelength sensitivity to produce a pattern comprising the steps of: providing a pulsed incoherent excimer laser; selecting an excimer medium for said excimer laser which produces a fundamental output of a predetermined wavelength; providing a Raman cell; selecting a suitable Raman medium for said Raman cell; directing the output of said pulsed incoherent excimer laser to said Raman cell to produce at least one secondary wavelength within said known wavelength sensitivity region by stimulated Raman scattering in said suitable medium contained in said Raman cell; and uniformly exposing over the area of said pattern, said photosensitive element to the output of said Raman cell to optimize exposure for said known sensitivity region.
Claim 11
Dependent Claim 68 words
Apparatus for exposing, in a contact or projection mode, an area of a photosensitive element to produce a pattern comprising: a pulsed incoherent excimer laser operable to produce a fundamental output of a predetermined wavelength; and means for directing the output of said excimer laser to uniformly expose, over the area of said pattern, said photosensitive element to the output at said predetermined wavelength to produce said pattern.
Claim 12
Dependent Claim 68 words
Apparatus for exposing, in a contact or projection mode, an area of a photosensitive element to produce a pattern comprising: a pulsed incoherent excimer laser operable to produce a fundamental output of a predetermined wavelength; and means for directing the output of said excimer laser to uniformly expose, over the area of said pattern, said photosensitive element to the output at said predetermined wavelength to produce said pattern.
Claim 13
Dependent Claim 18 words
The apparatus of claim 9 wherein said pulsed incoherent excimer laser includes a rare gas halide lasing medium.
Claim 14
Dependent Claim 24 words
The apparatus of claim 10 wherein said rare gas halide lasing medium is chosen from the group consisting of XeCl, KrF, KrCl and XeF.
Claim 15
Dependent Claim 30 words
The apparatus of claim 9 wherein said photosensitive element is chosen from the group consisting of novolak resin sensitized with a diazo ketone, poly(methyl methacrylate), and poly (methyl isopropenyl ketone).
Claim 16
Dependent Claim 18 words
The apparatus of claim 12 wherein said pulsed incoherent excimer laser includes a rare gas halide lasing medium.
Claim 17
Dependent Claim 24 words
The apparatus of claim 13 wherein said rare gas halide lasing medium is chosen from the group consisting of XeCl, KrF, KrCl, and XeF.
Claim 18
Dependent Claim 79 words
Apparatus for exposing, in a contact or projection mode, an area of a photosensitive element to produce a pattern comprising: pulsed incoherent excimer laser means for producing a plurality of fundamental outputs, each output having a predetermined wavelength different from the other predetermined wavelength; and means for directing the output of said excimer laser for uniformly exposing, over the area of said pattern, said photosensitive element to the outputs at said plurality of predetermined wavelengths to produce said pattern.
Claim 19
Dependent Claim 79 words
Apparatus for exposing, in a contact or projection mode, an area of a photosensitive element to produce a pattern comprising: pulsed incoherent excimer laser means for producing a plurality of fundamental outputs, each output having a predetermined wavelength different from the other predetermined wavelength; and means for directing the output of said excimer laser for uniformly exposing, over the area of said pattern, said photosensitive element to the outputs at said plurality of predetermined wavelengths to produce said pattern.
Claim 20
Dependent Claim 20 words
The apparatus of claim 15 wherein said pulsed incoherent excimer laser includes a plurality of rare gas halide lasing media.
Claim 21
Dependent Claim 26 words
The apparatus of claim 16 wherein said plurality of rare gas halide lasing media are chosen from the group consisting of XeCl, KrF, KrCl and XeF.
Claim 22
Dependent Claim 30 words
The apparatus of claim 15 wherein said photosensitive element is chosen from the group consisting of novolak resin sensitized with a diazo ketone, poly(methyl methacrylate), and poly (methyl isopropenyl ketone).
Claim 23
Dependent Claim 20 words
The apparatus of claim 18 wherein said pulsed incoherent excimer laser includes a plurality of rare gas halide lasing media.
Claim 24
Dependent Claim 26 words
The apparatus of claim 19 wherein said plurality of rare gas halide lasing media are chosen from the group consisting of XeCl, KrF, KrCl, and XeF.
Claim 25
Dependent Claim 95 words
Apparatus for exposing, in a contact or projection mode, an area of a photosensitive element to produce a pattern comprising: a pulsed incoherent excimer laser operable to produce a fundamental output of a predetermined wavelength; a Raman cell having a suitable Raman medium contained therein; means for directing said excimer laser output to said Raman cell to produce a secondary wavelength by stimulated Raman scattering in said suitable medium; and means for directing the output from said Raman cell to uniformly expose, over the area of said pattern, said photosensitive element to produce said pattern.
Claim 26
Dependent Claim 95 words
Apparatus for exposing, in a contact or projection mode, an area of a photosensitive element to produce a pattern comprising: a pulsed incoherent excimer laser operable to produce a fundamental output of a predetermined wavelength; a Raman cell having a suitable Raman medium contained therein; means for directing said excimer laser output to said Raman cell to produce a secondary wavelength by stimulated Raman scattering in said suitable medium; and means for directing the output from said Raman cell to uniformly expose, over the area of said pattern, said photosensitive element to produce said pattern.
Claim 27
Dependent Claim 18 words
The apparatus of claim 21 wherein said pulsed incoherent excimer laser includes a rare gas halide lasing medium.
Claim 28
Dependent Claim 24 words
The apparatus of claim 22 wherein said rare gas halide lasing medium is chosen from the group consisting of XeCl, KrF, KrCl and XeF.
Claim 29
Dependent Claim 30 words
The apparatus of claim 21 wherein said photosensitive element is chosen from the group consisting of novolak resin sensitized with a diazo ketone, poly(methyl methacrylate), and poly (methyl isopropenyl ketone).
Claim 30
Dependent Claim 18 words
The apparatus of claim 24 wherein said pulsed incoherent excimer laser includes a rare gas halide lasing medium.
Claim 31
Dependent Claim 24 words
The apparatus of claim 25 wherein said rare gas halide lasing medium is chosen from the group consisting of XeCl, KrF, KrCl, and XeF.
Claim 32
Dependent Claim 97 words
Apparatus for exposing, in a contact or projection mode, an area of a photosensitive element to produce a pattern comprising: a pulsed incoherent excimer laser operable to produce a fundamental output of a predetermined wavelength; a Raman cell having a suitable Raman medium contained therein; means for directing said excimer laser output to said Raman cell to produce a plurality of secondary wavelengths by stimulated Raman scattering in said suitable medium; and means for directing the outputs from said Raman cell to uniformly expose, over the area of said pattern, said photosensitive element to produce said pattern.
Claim 33
Dependent Claim 97 words
Apparatus for exposing, in a contact or projection mode, an area of a photosensitive element to produce a pattern comprising: a pulsed incoherent excimer laser operable to produce a fundamental output of a predetermined wavelength; a Raman cell having a suitable Raman medium contained therein; means for directing said excimer laser output to said Raman cell to produce a plurality of secondary wavelengths by stimulated Raman scattering in said suitable medium; and means for directing the outputs from said Raman cell to uniformly expose, over the area of said pattern, said photosensitive element to produce said pattern.
Claim 34
Dependent Claim 18 words
The apparatus of claim 27 wherein said pulsed incoherent excimer laser includes a rare gas halide lasing medium.
Claim 35
Dependent Claim 24 words
The apparatus of claim 28 wherein said rare gas halide lasing medium is chosen from the group consisting of XeCl, KrF, KrCl and XeF.
Claim 36
Dependent Claim 30 words
The apparatus of claim 27 wherein said photosensitive element is chosen from the group consisting of novolak resin sensitized with a diazo ketone, poly(methyl methacrylate), and poly (methyl isopropenyl ketone).
Claim 37
Dependent Claim 18 words
The apparatus of claim 30 wherein said pulsed incoherent excimer laser includes a rare gas halide lasing medium.
Claim 38
Dependent Claim 24 words
The apparatus of claim 31 wherein said rare gas halide lasing medium is chosen from the group consisting of XeCl, KrF, KrCl, and XeF.
Claim 39
Dependent Claim 103 words
Apparatus for exposing, in a contact or projection mode, an area of a photosensitive element to produce a pattern comprising: a pulsed incoherent excimer laser operable to produce a fundamental output of a predetermined wavelength; a Raman cell having a plurality of suitable Raman media contained therein; means for directing said excimer laser output to said Raman cell to produce a plurality of outputs of secondary wavelengths by stimulated Raman scattering in said plurality of suitable media; and means for directing the outputs from said Raman cell to uniformly expose, over the area of said pattern, said photosensitive element to produce said pattern.
Claim 40
Dependent Claim 103 words
Apparatus for exposing, in a contact or projection mode, an area of a photosensitive element to produce a pattern comprising: a pulsed incoherent excimer laser operable to produce a fundamental output of a predetermined wavelength; a Raman cell having a plurality of suitable Raman media contained therein; means for directing said excimer laser output to said Raman cell to produce a plurality of outputs of secondary wavelengths by stimulated Raman scattering in said plurality of suitable media; and means for directing the outputs from said Raman cell to uniformly expose, over the area of said pattern, said photosensitive element to produce said pattern.
Claim 41
Dependent Claim 18 words
The apparatus of claim 33 wherein said pulsed incoherent excimer laser includes a rare gas halide lasing medium.
Claim 42
Dependent Claim 24 words
The apparatus of claim 34 wherein said rare gas halide lasing medium is chosen from the group consisting of Xecl, KrF, KrCl and XeF.
Claim 43
Dependent Claim 30 words
The apparatus of claim 33 wherein said photosensitive element is chosen from the group consisting of novolak resin sensitized with a diazo ketone, poly(methyl methacrylate), and poly (methyl isopropenyl ketone).
Claim 44
Dependent Claim 18 words
The apparatus of claim 36 wherein said pulsed incoherent excimer laser includes a rare gas halide lasing medium.
Claim 45
Dependent Claim 24 words
The apparatus of claim 37 wherein said rare gas halide lasing medium is chosen from the group consisting of XeCl, KrF, KrCl, and XeF.
Claim 46
Dependent Claim 114 words
Apparatus for exposing, in a contact or projection mode, an area of a photosensitive element to produce a pattern comprising: a pulsed incoherent excimer laser operable to produce a plurality of fundamental outputs, each output having a predetermined wavelength different from the other predetermined wavelengths; a Raman cell having a suitable Raman medium contained therein; means for directing said excimer laser output to said Raman cell to produce an output of a secondary wavelength for each of said fundamental outputs by stimulated Raman scattering in said suitable medium; and means for directing the outputs from said Raman cell to uniformly expose, over the area of said pattern, said photosensitive element to produce said pattern.
Claim 47
Dependent Claim 114 words
Apparatus for exposing, in a contact or projection mode, an area of a photosensitive element to produce a pattern comprising: a pulsed incoherent excimer laser operable to produce a plurality of fundamental outputs, each output having a predetermined wavelength different from the other predetermined wavelengths; a Raman cell having a suitable Raman medium contained therein; means for directing said excimer laser output to said Raman cell to produce an output of a secondary wavelength for each of said fundamental outputs by stimulated Raman scattering in said suitable medium; and means for directing the outputs from said Raman cell to uniformly expose, over the area of said pattern, said photosensitive element to produce said pattern.
Claim 48
Dependent Claim 20 words
The apparatus of claim 39 wherein said pulsed incoherent excimer laser includes a plurality of rare gas halide lasing media.
Claim 49
Dependent Claim 26 words
The apparatus of claim 40 wherein said plurality of rare gas halide lasing media are chosen from the group consisting of XeCl, KrF, KrCl and XeF.
Claim 50
Dependent Claim 30 words
The apparatus of claim 39 wherein said photosensitive element is chosen from the group consisting of novolak resin sensitized with a diazo ketone, poly(methyl methacrylate), and poly (methyl isopropenyl ketone).
Claim 51
Dependent Claim 19 words
The apparatus of claim 42 wherein said pulsed incoherent excimer laser includes a plurality of rare gas halide media.
Claim 52
Dependent Claim 26 words
The apparatus of claim 43 wherein said plurality of rare gas halide lasing media are chosen from the group consisting of XeCl, KrF, KrCl, and XeF.
Claim 53
Dependent Claim 118 words
Apparatus for exposing, in a contact or projection mode, an area of a photosensitive element to produce a pattern comprising: a pulsed incoherent excimer laser operable to produce a plurality of fundamental outputs, each output having a predetermined wavelength different from the other predetermined wavelengths; a Raman cell having a plurality of suitable Raman media contained therein; means for directing said plurality of fundamental outputs to said Raman cell to produce a plurality of secondary wavelengths for each of said fundamental outputs by stimulated Raman scattering in said plurality of suitable media; and means for directing the outputs from said Raman cell to uniformly expose, over the area of said pattern, said photosensitive element to produce said pattern.
Claim 54
Dependent Claim 118 words
Apparatus for exposing, in a contact or projection mode, an area of a photosensitive element to produce a pattern comprising: a pulsed incoherent excimer laser operable to produce a plurality of fundamental outputs, each output having a predetermined wavelength different from the other predetermined wavelengths; a Raman cell having a plurality of suitable Raman media contained therein; means for directing said plurality of fundamental outputs to said Raman cell to produce a plurality of secondary wavelengths for each of said fundamental outputs by stimulated Raman scattering in said plurality of suitable media; and means for directing the outputs from said Raman cell to uniformly expose, over the area of said pattern, said photosensitive element to produce said pattern.
Claim 55
Dependent Claim 20 words
The apparatus of claim 45 wherein said pulsed incoherent excimer laser includes a plurality of rare gas halide lasing media.
Claim 56
Dependent Claim 26 words
The apparatus of claim 46 wherein said plurality of rare gas halide lasing media are chosen from the group consisting of XeCl, KrF, KrCl and XeF.
Claim 57
Dependent Claim 30 words
The apparatus of claim 45 wherein said photosensitive element is chosen from the group consisting of novolak resin sensitized with a diazo ketone, poly(methyl methacrylate), and poly (methyl isopropenyl ketone).
Claim 58
Dependent Claim 20 words
The apparatus of claim 48 wherein said pulsed incoherent excimer laser includes a plurality of rare gas halide lasing media.
Claim 59
Dependent Claim 26 words
The apparatus of claim 49 wherein said plurality of rare gas halide lasing media are chosen from the group consisting of XeCl, KrF, KrCl, and XeF.

References Cited (Backward Citations)

US4063192A Cited
US4195930A Cited
US4117177A Cited
US4194170A Cited
US4251625A Cited
US4144464A Cited
US4243881A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-07-10 1988-01-09 1988-07-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-07-10 1992-01-09 1992-07-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-07-10 1996-01-09 1996-07-10 $7700.00 Window Closed / Lapsed

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