Patent Number: 052296164
Section: claims

1. An exposure lamp for emitting incoherent far ultraviolet light to illuminate a substrate, said lamp enveloping a metal element which substantially consists of a single isotope of said metal element such that said incoherent far ultraviolet light is emitted on vaporization of said single isotope. 2. A lamp as claimed in claim 1, wherein said single isotope has a nuclear spin equal to zero. 3. A lamp as claimed in claim 1, wherein said metal element is an element selected from the group consisting of mercury (Hg), cadmium (Cd), zinc (Zn), and lead (Pb). 4. A lamp as claimed in claim 1, wherein said metal element is mercury and said single isotope is .sub.80 Hg.sup.196, .sub.80 Hg.sup.198, .sub.80 Hg.sup.199, .sub.80 Hg.sup.200, .sub.80 Hg.sup.201, .sub.80 Hg.sup.202, or .sub.80 Hg.sup.204. 5. A lamp as claimed in claim 1, wherein said metal element is lead and said single isotope is .sub.82 Pb.sup.204, .sub.82 Pb.sup.206, .sub.82 Pb.sup.207, or .sub.82 Pb.sup.208. 6. A lamp as claimed in claim 1, wherein said metal element is zinc and said single isotope is .sub.30 Zn.sup.64, .sub.30 Zn.sup.66, .sub.30 Zn.sup.67, .sub.30 Zn.sup.68, or .sub.30 Zn.sup.70. 7. A lamp as claimed in claim 1, wherein said metal element is cadmium and said single isotope is .sub.48 Cd.sup.106, .sub.48 Cd.sup.108, .sub.48 Cd.sup.110, .sub.48 Cd.sup.111, .sub.48 Cd.sup.112, .sub.48 Cd.sup.113, .sub.48 Cd.sup.114, or .sub.48 Cd.sup.116. 8. A lamp as claimed in claim 1, wherein said single isotope produces a light beam of said far ultraviolet light in a narrow bandwidth of less than 0.005 nm. 9. A lamp as claimed in claim 8, wherein said light beam produced by said single isotope has a wavelength of about 250 nm. 10. A lamp as claimed in claim 9, wherein said narrow bandwith and said wavelength of said light beam produced by said single isotope are effective when said lamp is utilized in combination in an exposure apparatus to illuminate a substrate for producing minimum pattern sizes of no more than 0.3 micron meters on said substrate. 11. A lamp as claimed in claim 1 further comprising means for receiving said far ultraviolet light as a beam of incoherent light and projecting said beam onto said substrate. 12. An exposure apparatus for use in exposing a substrate to manufacture a semiconductor device, said exposure apparatus comprising an exposure light source for emitting incoherent far ultraviolet light onto said substrate, said exposure light source comprising: a lamp enveloping a metal element which substantially consists of a single isotope such that said incoherent far ultraviolet light is emitted on vaporization of said single isotope. 13. An exposure apparatus as claimed in claim 12, wherein said single isotope has a nuclear spin equal to zero. 14. An exposure apparatus as claimed in claim 12, wherein said metal element is selected from the group consisting of mercury (Hg), lead (Pb), zinc (Zn), and cadmium (Cd). 15. An exposure apparatus as claimed in claim 12, wherein said metal element is mercury and said single isotope is .sub.80 Hg.sup.196, .sub.80 Hg.sup.198, .sub.80 Hg.sup.199, .sub.80 Hg.sup.200, .sub.80 Hg.sup.201, .sub.80 Hg.sup.202, or .sub.80 Hg.sup.204. 16. An exposure apparatus as claimed in claim 12, wherein said metal element is lead and said single isotope is .sub.82 Pb.sup.204, .sub.82 Pb.sup.206, .sub.82 Pb.sup.207, or .sub.82 Pb.sup.208. 17. An exposure apparatus as claimed in claim 12, wherein said metal element is zinc and said single isotope is .sub.30 Zn.sup.64, .sub.30 Zn.sup.66, .sub.30 Zn.sup.67, .sub.30 Zn.sup.68, or .sub.30 Zn.sup.70. 18. An exposure apparatus as claimed in claim 12, wherein said metal element is cadmium and said single isotope is .sub.48 Cd.sup.106, .sub.48 Cd.sup.108, .sub.48 Cd.sup.110, .sub.48 Cd.sup.111, .sub.48 Cd.sup.112, .sub.48 Cd.sup.113, .sub.48 Cd.sup.114, or .sub.48 Cd.sup.116. 19. An exposure apparatus as claimed in claim 12, further comprising optical means for receiving said far ultraviolet light from said light source as a beam of incoherent light and projection said beam onto said substrate. 20. A method of emitting far ultraviolet light from an exposure lamp to illuminate a substrate, said method comprising exciting an exposure lamp to vaporize a metal element in said lamp and produce a beam of incoherent far ultraviolet light, and selecting as said metal element a single isotope of said metal element so that said beam of incoherent far ultraviolet light has a wavelength of about 250 nm and a narrow bandwidth of less than 0.005 nm.